EMM COURSE FILE UPDATED.docx

MAR EPHRAEM COLLEGE OF ENGINEERING AND TECHNOLOGY
Department of Mechanical Engineering
ME6403 ENGINEERING METALLURGY ACADEMIC YEAR2019-20
Course file - ME8491 -ENGINEERING METALLURGY
Name of Course instructor A. JUDE FELIX
Email judefelix@marephraem.edu.in
Contact number +91-8903787202
COURSE CONTENT
The whole course is divided into 5 Units.
48 lecture hours.
ME6702 ENGINEERING METALLURGY L T P
UNITI ALLOY AND PHASE DIAGRAM 8 0 0
UNITII HEAT TREATMENT 10 0 0
UNITIII FERROUSAND NON FERROUSMETALS 10 0 0
UNITIV NON METALLICMATERIALS 9 0 0
UNITV MECHANICAL PROPERTIESANDTESTING 11 0 0
TOTAL 48 0 0
Prerequisitefor theprogram:
SEMESTERII– Material science
Courseoutcomes:
CO1 Explain alloys and phase diagram, Iron-Iron Carbon diagram and steel classification
CO2 Describe the effectof heat treatment processes.
CO3 Explain the effectof alloying elements on ferrous and non-ferrous metals
CO4 Summarize the propertiesandapplicationsof nonmetallicmaterials.
CO5 Explain the types of mechanical testing.
CO6 Describe fatigue and creep failure mechanisms

Programoutcomes:
POs Statements
PO1
EngineeringKnowledge:
Apply the knowledgeof mathematics, science, engineering fundamentals, and an
engineering specialization to the solution of complex engineering problems.
PO2
Problemanalysis:
Identify,formulate, review research literature, and analyze complex engineering
problem researching substantiated conclusions using first principles of mathematics,
natural sciences, and engineering sciences.
PO3
Design/developmentofsolutions:
Design solutions forcomplex engineering problems and design system components or
processes that meet the specified needs with appropriate consideration for the public
health and safety, and the cultural, societal, and environmental considerations.
PO4
Conductinvestigationsofcomplexproblems:
Use research-based knowledge and research methods including design of experiments,
analysis and interpretation of data, and synthesis of the information to provide valid
conclusions.
PO5
Moderntool usage:
Create, select, and apply appropriate techniques, resources, and modern engineering
and ITtools including prediction and modeling to complex engineering activities with
an understanding of the limitations.
PO6
Theengineerandsociety:
Apply reasoning informed by the contextual knowledge to assess societal, health, safety,
legal and cultural issues and the consequent responsibilities relevant to the professional
engineering practice.
PO7
Environmentandsustainability:
Understand the impact of the professional engineering solutions in societal and
environmental contexts, and demonstrate the knowledge of, and need for sustainable
development.
PO8
Ethics:
Apply ethical principles and commit to professional ethics and responsibilities and
norms of the engineering practice.
PO9
Individual andteam work:
Function effectively asan individual, and as a member or leader in diverse teams, and in
multidisciplinary settings.
PO10
Communication:
Communicate effectively oncomplex engineering activities with the engineering
community and with society at large, such as, being able to comprehend and write
effectivereports and design documentation, make effectivepresentations, and give and

receive clear instructions.
PO11
Project managementand finance:
Demonstrate knowledge and understanding of the engineering and management
principles and apply these to one’s ownwork,as a member and leader in a team, to
manage projects and in multidisciplinary environments.
PO12
Life-longlearning:
Recognize the need for, and have the preparation and ability to engage in independent
and life-long learning in the broadest context of technological change.
CO PO Mapping:
CO CL PO1 PO2 PO3 PO4 PO5 PO6 PO7 PO8 PO9 PO10 PO11 PO12
CO
1
U
2 1 - - - - - - - - - -
CO
2
U 2 1 - - - - - - - - - 2
CO
3
U
2 1 - - - - - - - - - 2
CO
4
U
2 1 - - - - 2 - - - - -
CO
5
U 2 1 - - - - - - - - - 2
CO
6
U 2 1 - - - - 0 - - - - -
Average 2.00 1.00 - - - - 2.00 - - - - 2.00
CO-PSO Mapping
CO PSO1 PSO 2 PSO 3
CO 1 - - 2
CO 2 2 - 2
CO 3 - - 2
CO 4 - - 2
CO 5 - - 2
CO 6 - - 2
Average 2.00 - 2.00

COURSE SYLLABUS:
Unit
No
Unit Title
Unit wise Syllabus
1 ALLOY AND PHASE
DIAGRAM
Constitution of alloys – Solid solutions, substitutional
and interstitial – phase diagrams, Isomorphous, eutectic,
eutectoid, peritectic, and peritectoid reactions, Iron –
carbon equilibrium diagram. Classification of steel and
cast Iron microstructure, properties and application
2 HEAT TREATMENT Definition – Full annealing, stress relief, recrystallisation
and spheroidising – normalising, hardening and
Tempering of steel. Isothermal transformation diagrams
– cooling curves superimposed on I.T. diagram CCR –
Hardenability, Jominy end quench test - Austempering,
martempering – case hardening, carburizing, Nitriding,
cyaniding, carbonitriding – Flame and Induction
hardening – Vacuum and Plasma hardening
3 FERROUSAND NON
FERROUSMETALS
Effect of alloying additions on steel- α and β stabilisers–
stainless and tool steels – HSLA, Maraging steels – Cast
Iron - Grey, white, malleable, spheroidal – alloy cast
irons, Copper and copper alloys – Brass, Bronze and
Cupronickel – Aluminium and Al-Cu – precipitation
strengthening treatment – Bearing alloys, Mg-alloys, Ni-
based super alloys and Titanium alloys...
4 NON METALLIC
MATERIALS
Polymers – types of polymer, commodity and
engineering polymers – Properties and applications of
various thermosetting and thermoplastic polymers (PP,
PS, PVC, PMMA, PET,PC, PA, ABS, PI, PAI, PPO,
PPS, PEEK, PTFE, Polymers – Urea and Phenol
formaldehydes)- Engineering Ceramics – Properties and
applications of Al2O3, SiC, Si3N4, PSZ and SIALON –
CompositesClassifications- Metal Matrix and FRP -
Applications of Composites..
5 MECHANICAL PROPERTIES
AND TESTING
Mechanisms of plastic deformation, slip and twinning –
Types of fracture – Testing of materials under tension,
compression and shear loads – Hardness tests (Brinell,
Vickers and Rockwell), hardness tests, Impact test lzod
and charpy, fatigue and creep failure mechanisms.
ASSESSMENT
DIRECT ASSESSMENT
1. CONTINUOUS INTERNALASSESSMENT (CIA):
 CAE 1
 CAE 2
 MODEL

 ASSIGNMENT 1
 ASSIGNMENT 2
 ASSIGNMENT 3
2. SEMESTER END EXAMINATION (SEE)
INDIRECT ASSESSMENT
 COURSE EXIT SURVEY
INTERNALASSESSMENTPLAN
Assessment Total Marks Tentative Schedule
CAE 1 50 Feb 2nd week 2019
CAE 2 50 March 3rd week 2019
ME 100 April 1st week 2019
A1 20 To be submitted in Feb 4th week 2019
A2 20 To be submitted in March 2nd week2019
A3 20 To be submitted in April 1st week 2021
CO markssplitup- Internal Assessment:
CO CAE 1 CAE 2 ME A1 A2 A3
CO 1 30 - 17 10 - -
CO 2 20 - 17 10 - -
CO 3 - 17 17 - 10 -
CO 4 - 33 17 - 10 -
CO 5 - - 17 - - 10
CO 6 - - 15 - - 10

NOTE:
CAE 1- CONTINUOUS ASSESSMENT EXAMINATION1
CAE 2- CONTINUOUS ASSESSMENT EXAMINATION2
ME-MODELEXAMINATION1
List of students
Sl no
Register Number Name
1.
961416114001 ABHIJITH K
2.
961416114002 ABHINAND D S
3.
961416114003 ABILASH A
4.
961416114004 ABINESH E
5.
961416114005 ABIN S
6.
961416114006 ABIN SAM ABRAHAM
7.
961416114007 AGABOS M JACOB
8.
961416114008 AHIN T A
9.
961416114010 AJASHA J A
10.
961416114011 AJESH B S
11.
961416114012 AJIN J RAJENDRAN
12.
961416114013 AJIN P RAJ
13.
961416114014 AJITH KUMAR R
14.
961416114016 AKHIL K SHIBU
15.
961416114017 AKHILNATH S S
16.
961416114018 AKHIL P JOSE
17.
961416114019 AKHIL RAJ P
18.
961416114020 AKILAN H
19.
961416114021 AKSHAY V NAIR
20.
961416114022 ALAN ALEX
21.
961416114023 ALAN P WILSON
22.
961416114024 ALAN S ABRAHAM
23.
961416114025 ALEN CHRIS BIJU

24.
961416114026 ALEX M JOHNSON
25.
961416114027 ALLEN SABU DANIEL
26.
961416114028 ALPHIN A
27.
961416114029 AMAL V SKARIA
28.
961416114030 ANANDHU LAL
29.
961416114031 ANISH P
30.
961416114032 ANISH THOMAS
31.
961416114033 ANSLY NITHIN S
32.
961416114034 ANTO RUFUS G
33.
961416114035 ARAVIND A KURUP
34.
961416114036 ARAVIND GOPAL M J
35.
961416114037 ARAVINDHU M
36.
961416114038 ARJUNAN K
37.
961416114040 ASHIK SAJI JOHN
38.
961416114041 BELBIN J
39.
961416114042 BENISH JEBIN S
40.
961416114044 BIBIN FRANCIS
41.
961416114045 BLESSIN S V
42.
961416114046 CYRIAC VARGHESE
43.
961416114047 DHANUSH A
44.
961416114048 DOMINIC THOMAS
45.
961416114049 ELISHA G JOY
46.
961416114050 FELIX JOHN THOMAS
47.
961416114051 GAUTHAM KRISHNA
48.
961416114054 JAISON J THARAKAN
49.
961416114055 JEFFIN BINU JOHN
50.
961416114057 JESBIN JACOB KURIAN
51.
961416114058 JILLS GEEVARUGHESE SIMON
52.
961416114059 JINO MON M
53.
961416114060 JITHIN M ABEY

54.
961416114061 JITHU JOSE
55.
961416114062 JOBIN GEORGE
56.
961416114063 JOBIN JOSE
57.
961416114064 JOBIN T EAPEN
58.
961416114065 JOEL KURUVILLA MATHEW
59.
961416114066 JOMON M
60.
961416114067 JUSTIN NOYAL
61.
961416114068 KEVIN J MATHEW
62.
961416114069 KIRAN KRISHNA
63.
961416114070 MELVIN SAJI
64.
961416114071 MIDHUN BIJU
65.
961416114072 MOHAMED FARHAN
66.
961416114073 NAYANRAJ S R
67.
961416114074 NEJIN INFANT N C
68.
961416114075 NIHIL ANAND G M
69.
961416114076 NITHIN R V
70.
961416114077 NITHIN SURESH
71.
961416114078 PRABIN G
72.
961416114079 PRABIN Y
73.
961416114080 PRAKASH P
74.
961416114081 RAJ VIMAL S V
75.
961416114082 RAKESH C
76.
961416114083 RATHEESH D
77.
961416114084 RINU THOMAS
78.
961416114086 ROSHAN RAJU
79.
961416114087 SACHIN THOMAS
80.
961416114088 SACHIN VARGHESE MATHEW
81.
961416114090 SALBIN S VARGHESE
82.
961416114092 SARAN S NAIR
83.
961416114093 SEBIN JOSE

84.
961416114094 SHAINU S
85.
961416114095 SHARON SEBASTIAN
86.
961416114096 SHAWN A MATHEW
87.
961416114097 SHIBU T
88.
961416114098 SHIJO PAUL C M
89.
961416114099 SHIJU V
90.
961416114100 SHON SAM RAJU
91.
961416114101 SHYAM LAMBERT
92.
961416114102 SIBIN VARGHESE B
93.
961416114103 SIGO GEORGE
94.
961416114105 SIVA J
95.
961416114106 SOJU BIJOY
96.
961416114108 SONU ABIN BABU
97.
961416114109 STEFFIN P VARGHESE
98.
961416114110 THOMAS BABU
99.
961416114111 THOMAS KURIAN
100.
961416114112 TOM THOMAS (26-12-1996)
101.
961416114113 TOM THOMAS (21-04-1999)
102.
961416114114 TOM VARGHESE
103.
961416114115 VIBIN JOSE V
104.
961416114116 VIBIN P
105.
961416114117 VIBIN VARGHESE
106.
961416114118 VIJAY A S
107.
961416114119 VINOTH V
108.
961416114120 VISHNU S
109.
961416114301 AJIN DAS Y
110.
961416114302 AJIN MON R S
111.
961416114303 ALEX VARGHESE
112.
961416114304 ASWIN RAJA M R
113.
961416114305 HELWIN JOHN J S

114.
961416114307 LESLIN EMERSON S
115.
961416114308 MUHAMMED HASINSHA P S
116.
961416114309 PRINCE RAJU
117.
961416114310 RENJITH R
118.
961416114312 SARAVANAN R
119.
961416114313 SHOBIN GEORGE CHERIAN
120.
961416114701 ASWIN GEO S E
121.
961416114702 SOWMIYA M
122.
961416114703 STEBIN S
123.
961416114901 JOHNSTON CHRYSLER A
124.
961416114902 MONISH M
125.
126.
Lesson plan:
SlNo
Unit
Number
Lesson
Number
Lesson Topics L
1. 1 1 CONSTITUTIONOFALLOY L
2. 1 2
PHASE DIAGRAM, ISOMORPHOUS
L
3. 1 3 PHASE DIAGRAM EUTECTOIDREACTIONS L
4. 1 4 PHASE DIAGRAM EUTECTICREACTION L
5. 1 5 PHASE DIAGRAM PERITECTICREACTION L
6. 1 6 PHASE DIAGRAM PERITECTROIDREACTION L
7. 1 7 IRON-IRONCARBIDE EQUILIBRIUMDIGRAM L
8. 1 8 CLASSIFICATION OF STEELAND CAST IRON,
MICROSTRUCTURE,PROPERTIESANDAPPLICATIONS
L
9. 2 9 ANNEALING AND ITS TYPES L
10. 2 10 NORMALISING, HARDENINGAND TEMPERINGOF
STEEL
L
11. 2 11 ISOTHERMALTRANSFORMATIONDIAGRAM L

12. 2 12 COOLINGCURVE SUPERIMPOSEDONI.T.DIAGRAM L
13. 2 13 CRITICAL COOLINGRATE L
14. 2 14 HARDENABILITY,JOMINY ENDQUENCHTEST L
15. 2 15 AUSTEMPERING,MARTEMPERING L
16. 2 16 MARTEMPERINGORMARQUENCHINGOR
INTERRUPTEDQUENCHING
L
17. 2 17 CASE HARDENING L
18. 2 18 CARBURISING, NITRIDING,CYANIDING,
CARBONITRIDING,FLAME AND INDUCTION
HARDENING
L
19. 3 19 EFFECTOF ALLOYINGELEMENTONSTEEL(Mn,Si,Cr,
Mo, V,& W)
L
20. 3 20 CHARACTERISTICS OF ALLOYINGELEMENT L
21. 3 21 STAINLESS AND TOOLSTEEL L
22. 3 22 HSLA-MARAGING STEELS L
23. 3 23 CAST IRON-GREY,WHITE MALLEABLE,SPHEROIDAL L
24. 3 24 GRAPHITE,ALLOY CAST IRONS, COPPERAND COPPER
ALLOY
L
25. 3 25 BRASS, BRONZE AND CUPRONICKEL L
26. 3 26 ALUMINIUMAND Al-Cu ALLOY L
27. 3 27 PRECIPITATIONHARDENING L
28. 3 28 BEARING ALLOY L
29. 4 29 POLYMER L
30. 4 30 TYPESOFPOLYMER L
31. 4 31 COMMODITY ANDENGINEERINGPOLYMER L
32. 4 32 PROPERTIESANDAPPLICATIONOFPE,PP,PS,PVC L
33. 4 33 PROPERTIESAND APPLICATIONOFPMMA,PET,PC,PA,
ABS
L
34. 4 34 PROPERTIESANDAPPLICATIONOFPI,PAI,PPO,PPS,
PEEK,PTFE POLYMERS
L
35. 4 35 UREAAND PHENOLFORMALDEHYDES L

36. 4 36 ENGINEERINGCERAMICS L
37. 4 37 INTRODUCTIONTOFIBRE REINFORCEDPLASTICS L
38. 5 38 MECHANISM OF PLASTICS DEFORMATION,SLIP AND
TWINING
L
39. 5 39 TYPESOFFRACTURE L
40. 5 40 BRITTLE FRACTURE L
41. 5 41 SHEARING FRACTURE L
42. 5 42 TESTINGOF MATERIALUNDERTENSION L
43. 5 43 TESTINGON MATERIALUNDERCOMPRESION L
44. 5 44 TESTINGON MATERIALUNDERSHEAR LOAD L
45. 5 45 HARDNESS TESTING (BRINEL,VICKERS AND
ROCKWELL)
L
46. 5 46 IMPACTTEST- IZODAND CHARPY L
47. 5 47 FATIGUE AND CREEP TEST L
48. 5 48 FRACTURE TOUGNNESSTEST L

Course content
Lesson Title CONSTITUTION OF ALLOY
Lesson concept/
Points/Definitions
Constitution of Alloys
 An alloy is a mixture or metallic solid solution composed of two or
more elements.
 Alloying a metal is done by combining it with one or more other
metals or non-metals that often enhance its properties. For
example,steel is stronger than iron, its primary element.
 The term alloy is used to describe a mixture of atoms in which the
primary constituent is a metal. The primary metal is called the base,
the matrix, or the solvent. The secondary constituents are often
called solutes.
 A solvent is a substance that dissolves a solute (a chemically
different liquid, solid or gas), resulting in a solution.
 If there is a mixture of only two types of atoms, not counting
impurities, such as a copper-nickel alloy, then it is called a binary
alloy.
 If there are three types of atoms forming the mixture, such as iron,
nickel and chromium, then it is called a ternary alloy.
 An alloy with four constituents is a quaternary alloy, while a five-
part alloy is termed a quinary alloy.
 Because the percentage of each constituent can be varied, with any
mixture the entire range of possible variations is called a system.
Solid Solutions, Substitutional and Interstitial
 A solid solution is a solid-state solution of one or more solutes in
a solvent.
 When a molten metal is mixed with another substance, there are
two mechanisms that can cause an alloy to form, called atom
exchange and the interstitial mechanism.
 When the atoms are relatively similar in size, the atom exchange

method usually happens, where some of the atoms composing the
metallic crystals are substituted with atoms of the other constituent.
This is called a substitutional alloy.
Teaching
Methodology:
PPT - UNIT I- CONSTITUTION OF ALLOY AND PHASE DIAGRAM
Learning
Resource (page
number)
T2- (1 to 15)
R1- (10 to 12)
Lesson Title PHASE DIAGRAM,ISOMORPHOUS
Lesson concept/
Points/Definitions
Phase diagram is a diagram representing the limits of stability of the various phases
in a chemical system at equilibrium, with respect to variables such as composition
and temperature.
Common components of a phase diagram are lines of equilibrium or phase
boundaries, which refer to lines that mark conditions under which multiple phases
can coexist at equilibrium. Phase transitions occur along lines of equilibrium.
Triple points are points on phase diagrams where lines of equilibrium intersect.
Triple points mark conditions at which three different phases can coexist.
For example, the water phase diagram has a triple point corresponding to the single
temperature and pressure at which solid, liquid, and gaseous water can coexist in a
stable equilibrium.
The solidus is the temperature below which the substance is stable in the solid state.
The liquidus is the temperature above which the substance is stable in a liquid state.
There may be a gap between the solidus and liquidus; within the gap, the substance
consists of a mixture of crystals and liquid like a "slurry".
A slurry is a thin sloppy mud or cement or, in extended use, any fluid mixture of a
pulverized solid with a liquid (usually water), often used as a convenient way of
handling solids in bulk.
Slurries behave in some ways like thick fluids, flowing under gravity and being
capable of being pumped if not too thick.
The phase boundary which limits the bottom of the liquid field is called the liquidus

line.
The line giving the upper limit of the single phase solid field is called the solidus
line.
Isomorphous binary phase diagrams are found in a number of metallic and ceramic
systems. In the isomorphous systems, only one solid phase forms; the two
components in the system display complete solid solubility.
Typically, the isomorphous system has a liquid area, a solid area, and an area that is
a mixture of both liquid and solid. Typically, a binary isomorphous phase diagram
consists of two phase boundaries: the liquidus and the solidus.
Teaching
Methodology:
Learning
Resource (page
number)
T1-23
R1- (4 to 5)
Lesson Title PHASE DIAGRAMS EUTECTOID REACTIONS
Lesson concept/
Points/Definitions
Definition: A eutectoid reaction is a three-phase reaction by which, on cooling, a
solid transforms into two other solid phases at the same time. If the bottom of a
single-phase solid field closes (and provided the adjacent two-phase fields are solid
also), it does so with a eutectoid point.
The eutectoid reaction describes the phase transformation of one solid into two
different solids.
In the Fe-C system, there is a eutectoid point at approximately 0.8wt% C, 723°C.
Eutectoid point – here, the three phases are in equilibrium. The compositions of
the two new phases are given by the ends of the line through the eutectoid point.
The phase just above the eutectoid temperature for plain carbon steels is known as
austenite or gamma.
The compositions of the two new phases are given by the ends of the tie-line
through the eutectoid point. The general eutectoid reaction is therefore:
Solid γ –> solid α + solid β
or using the names given to these phases:
Austenite –> ferrite + cementite (Fe3C)
The mechanism of eutectoid transformation must transform a single solid phase into
two others, both with compositions which differ from the original.
Taking the eutectoid decomposition of iron as an example, austenite containing
0.8% C changes into ferrite (iron containing almost no carbon) and cementite (Fe3C,
containing 25 at% carbon). Hence carbon atoms must diffuse together to form Fe3C,
leaving ferrite.
Nuclei of small plates of ferrite and cementite form at the grain boundaries of the

austenite, and carbon diffusion takes place on a very local scale just ahead of the
interface (schematic below). Thus, the plates grow, consuming the austenite as they
go, to form pearlite.
The eutectoid structure in iron has a special name: it is called pearlite (because it
has a pearly look).
Some commercial steels have a eutectoid composition - steel for railway track is an
example of a "pearlitic steel
Teaching
Methodology:
Learning
Resource (page
number)
T1-(27-28) ; T2-(73-88)
R1- (10,13 to 26)
Lesson Title PHASE DIAGRAMS EUTECTIC REACTIONS
Lesson concept/
Points/Definition
s
A EUTECTIC REACTION is a three-phase reaction by which, on cooling, a liquid
transforms into two solid phases at the same time. It is a phase reaction, of course, but a
special one. If the bottom of a liquid-phase field closes with a V, the bottom of the V is
a eutectic point.
The lower limit of the single-phase liquid field formed by the intersection of two
liquidus lines is called the eutectic point.
A eutectic system is a mixture of chemical compounds or elements that has a single
multiple chemical composition that solidifies at a lower temperature than any other
composition made up of the same ingredients. This composition is known as
the eutectic composition and the temperature is known as the eutectic temperature.
The eutectic reaction is defined as follows:
This type of reaction is an invariant reaction (A function, quantity, or property that
remains unchanged when a specified transformation is applied.), because it is in thermal
equilibrium; another way to define this is the Gibbs free energy equals zero.
Definition: Gibbs free energy is a thermodynamic property that was defined in 1876
by Josiah Willard Gibbs to predict whether a process will occur spontaneously at
constant temperature and pressure. Gibbs free energy G is defined as G = H - TS where
H, T and S are the enthalpy, temperature, and entropy.
Changes in the Gibbs free energy G correspond to changes in free energy for processes
at constant temperature and pressure
Teaching
Methodology:

Learning
Resource
(page number)
R4- (153,174)
Lesson Title PHASE DIAGRAMS PERITECTIC REACTIONS
Lesson concept/
Points/Definitions
Peritectic reaction where a solid phase reacts with a liquid phase to produce a new
solid phase.
Peritectic reaction is commonly present as part of more-complicated binary
diagrams, particularly if the melting points of the two components are quite different.
Peritectic reaction do not give rise to micro-constituents as the eutectic and eutectoid
reactions do.
The term “peritectic,” or “peritectic point,” is often used to designate the point of
intersection between the temperature lines on a phase diagram at the onset of
crystallization of two solid phases in equilibrium with a peritectic liquid.
Peritectic point - The point on a phase diagram where a reaction takes place between
a previously precipitated phase and the liquid to produce a new solid phase. When this
point is reached, the temperature must remain constant until the reaction has run to
completion.
A peritectic is also an invariant point.
Teaching
Methodology:
Learning
Resource (page
number)
T1- (74 to 91); T2(16-36)
Lesson Title PHASE DIAGRAMS PERITECTROID REACTIONS
Lesson concept/
Points/Definitions
Peritectoid is a three-phase reaction similar to peritectic but occurs from
twosolid phases to one new solid phase (α + β = γ).
Peritectoid reactions do not give rise to micro-constituents as the eutectic
and eutectoid reactions do
Teaching
Methodology:
Learning
Resource (page
number)
T1- (103 to 105) T2 (89-90)
Lesson Title IRON – IRON CARBIDE EQUILIBRIUM DIAGRAM.
Lesson concept/ Steels are the most complex and widely used engineering materials because

Points/Definitions of the abundance of iron in the earth’s crust, high melting temperature of
iron (1534°C), and wide range of mechanical properties and associated
microstructures produced by solid-state phase transformations by varying
the cooling rate from the austenitic condition.
The iron-cementite phase diagram is the very useful foundation on which
analysis of all steel heat treating processes depends, whereas both iron-
cementite and iron-graphite diagrams are useful for the heat treatment of
cast iron.
The phase diagram is a map showing structures or phases and phase
boundaries present as the temperature and overall composition of the alloy
are varied under constant pressure (usually 1 atm).
Ferrite also known as α-ferrite (α-Fe) or alpha iron is a materials
science term for iron, or a solid solution with iron as the main constituent,
with a body-centered cubic crystal structure.
The bcc structure of pure iron at room temperature, called either α -iron or
ferrite, has one atom at the center of the cube and an atom at each corner of
the unit cell and constitutes 1 + (8 1/8) = 2 atoms per unit cell.
The atomic packing factor for this structure is 0.68 and represents the
volume fraction of the unit cell occupied by two atoms. The lattice
parameter of a-iron at room temperature is 2.86Å.
Ferrite is ferromagnetic below 768°C (1414°F) and paramagnetic in the
temperature range of 768 to 910°C (1414 to 1670°F). The temperature at
which this magnetic transformation takes place is called the Curie
temperature.
Austenite, also known as gamma phase iron (γ-Fe), is a metallic, non-
magnetic allotrope of iron or a solid solution of iron, with
analloying element. In plain-carbon steel, austenite exists above the

criticaleutectoid temperature of 1,000 K (1,300 °F); other alloys ofsteelhave
different eutectoid temperatures. It is named after Sir William Chandler
Roberts-Austen(1843–1902)
Austenite as well as other metals such as Al, Ni, Cu, Ag, Pt, and Au have the
close packed face-centered cubic (fcc) structure.
Delta Iron
The third phase that occurs in pure iron is δ-iron or ferrite with a bcc
structure, which is crystallographically similar to alpha-iron.
Delta-iron is stable at temperature between 1393 and 1534°C (2540 and
2793°F). Its lattice parameter is 2.89Å; it is also soft and ductile, and its
hardness and elongation are similar to those of ferrite and austenite in their
stable forms.
CRITICAL TEMPERATURES
There are three transformation temperatures, often referred to as critical
temperatures, which are of interest in heat treatment of steels.
The temperature A1 is the eutectoid temperature of 723°C in the binary
phase diagram which is the boundary between ferrite-cementite field and the
austenite-ferrite or austenite-cementite field.
Temperature A3 is the temperature at which α-iron transforms to γ-iron,
which, for pure iron, occurs at 910°C. The A3 line represents the boundary
between the ferrite-austenite and austenite fields.
Teaching
Methodology:
Learning
Resource (page
number)
R41- (68to 69)
Lesson Title CLASSIFICATION OF STEEL AND CAST IRON
Lesson
concept/
Points/Definiti
ons
Steels can be classified by severaldifferent systems depending on
(1) The compositions, such as carbon, low-alloy, alloy, or stainless steels;
(2) The manufacturing methods, such as basic and acid open hearth, or electric furnace
methods;
(3) The finishing methods, such as hot rolling or cold rolling;
(4) The product shape,such as bar, plate, strip, tubing, or structural shape;
(5) The application, such as structural, spring, and high tensile steels;
(6) The deoxidation practice, such as killed, semikilled, capped, and rimmed steels;
(7) The microstructure, such as ferritic, pearlitic, and martensitic;
(8) The required strength level, as specified in ASTM Standards;
(9) Heat treatment, such as annealing, quenching and tempering, and thermomechanical
processing;
(10) Quality descriptors/classifications, such as forging quality and commercial quality
Stainless Steels. Stainless may be defined as complex alloy steels containing a minimum
of 10.5% Cr with or without other elements to produce austenitic, ferritic, duplex (ferritic-
austenitic), martensitic, and precipitation hardening grades.
Maraging Steels. Maraging steels are a specific class of low-carbon ultrahigh-strength
steels which derive their strength not from carbon but from precipitation of intermetallic
compounds.
CAST IRON CLASSIFICATIONS
There are six generic types of cast irons. In each type, there are several grades, such as (1)
white iron, (2) gray iron, (3) ductile iron, (4) compacted graphite iron, (5) malleable iron,

and (6) high-alloy irons.
White Cast Iron
If the chemical composition of the alloy lies in the white cast iron range (Table 1.15) and
the solidification rate is quite rapid, a white cast iron will be produced.
In white cast iron, the carbon in the molten iron combines with the iron and, upon
solidification, forms iron carbide or cementite, which is a hard and brittle compound and
dominates the microstructure of white iron.
White cast iron has an exceptionally high compressive strength and a very high abrasive
wear resistance,and it retains its hardness for limited periods even up to red heat.
Gray Cast Iron
When the composition of the cast iron is in the gray cast iron range (Table 1.15) and the
solidification rate is appropriate, the carbon in the iron separates and forms distinct
graphite flake morphologies.
These graphite flakes become interconnected within each eutectic cell as the gray iron
solidifies. This characteristic flake morphology exerts a marked influence on the
mechanical and physical properties of gray irons.
Ductile Iron
Ductile iron, developed in 1940s, has grown in relative importance over the last two
decades and now constitutes about 25% of cast iron production in most industrialized
countries.
Ductile iron has its free carbon formed as graphite spheroids (or spherulites) rather than as
flakes. These nodules act as “crack arresters” and make ductile iron “ductile.”
Compacted Graphite (CG) Iron
A recently developed type of cast iron is called compacted graphite iron or vermicular
graphite iron.
CG iron has a graphite structure intermediate between that of gray iron and ductile iron.
The “worm-shaped” compacted graphite particles are elongated and interconnected within
each eutectic cell (similar to flake graphite morphology of gray iron), thereby providing
high thermal conductivity and vibration damping, and have the rounded or blunt edges
(similar to spheroidal graphite structure of ductile iron) providing high strength, stiffness,
and excellent fatigue property.
Their castability, machinability, dimensional stability, and thermal conductivity are
superior to those for ductile iron.
Malleable Iron
The necessary requirements for malleable cast iron production are low CE and
graphitization potential to ensure that it solidifies as white iron with a metastable carbide
structure in a pearlitic matrix.
Malleable cast iron is characterized by having most of its carbon present as irregularly

shaped nodules of graphite. This form of graphite is called temper carbon nodules (Type
III in ASTM Standard A247) because it is formed by the decomposition of Fe3C in the
solid state after an extended heat treatment of white cast iron of suitable composition in a
controlled atmosphere furnace to a temperature above the eutectoid temperature, usually
900°C (1650°F)
High-Alloy Iron
This group of cast irons includes high-alloy white irons, high-alloy gray irons, and high-
alloy ductile irons.
Usually, malleable irons are not highly alloyed because there is interference with the
malleabilizing process. CG irons have not been studied well in the highly alloyed
condition.
High-alloy irons are used in applications requiring high strength, hardness, and
hardenability or improved resistance to abrasive wear, heat, and chemical corrosion
properties and whenever special-purpose physical properties such as low thermal
expansion and nonmagnetic properties are in demand
Teaching
Methodology:
Learning
Resource
(page
number)
T2- (93 to 101)
Lesson Title ANNEALING
Lesson concept/
Points/Definitions
Annealing is commonly used after casting, forging or rolling to soften
materials and minimise residual stresses, improve machinability, and
increase ductility by carefully controlling the microstructure.
There are several process variations that qualify as annealing
treatments:
 Full annealing is performed on steels by heating to a high
temperature (typically 830-950°C), then cooling slowly to
ambient temperature. Non-ferrous materials are softened and
refined by full annealing at temperatures appropriate for each
alloy.
 Isothermal/cyclic annealing is performed by heating steels to
the full annealing temperature, cooling to an intermediate
temperature (typically 550- 700°C) and soaking for a long
period to allow transformation to proceed slowly, followed by
cooling to ambient temperature.
 Inter-critical annealing is applied by heating steels to below
the full annealing temperature (typically 723- 910°C)
according to composition. A prolonged soak is followed by
 Subcritical annealing takes place at a temperature for steels of
typically 650 - 720°C, allowing a prolonged soak before

 Homogenisation annealing can be applied to both ferrous and
non-ferrous materials and is a prolonged high-temperature
soak intended to break down segregation in the material s
structure.
 Solution annealing is applied commonly to austenitic stainless
steels, typically at 1010-1150°C. With unstabilised grades, the
treatment must be followed by fast cooling or quenching. It is
applied as a softening process during manufacture or to
optimise corrosion resistance (e.g. after welding).
Full annealing is the process of slowly raising the temperature about
50 ºC (90 ºF) above the Austenitic temperature line A3 or line ACM in
the case of Hypoeutectoid steels (steels with < 0.77% Carbon) and 50
ºC (90 ºF) into the Austenite-Cementite region in the case of
Hypereutectoid steels (steels with > 0.77% Carbon). It is held at this
temperature for sufficient time for all the material to transform into
Austenite or Austenite-Cementite as the case may be. It is then slowly
cooled at the rate of about 20 ºC/hr (36 ºF/hr) in a furnace to about 50
ºC (90 ºF) into the Ferrite-Cementite range. At this point, it can be
cooled in room temperature air with natural convection.
Stress Relief Annealingl is used to reduce residual stresses in large
castings, welded parts and cold-formed parts. Such parts tend to have
stresses due to thermal cycling or work hardening. Parts are heated to
temperatures of up to 600 - 650 ºC (1112 - 1202 ºF), and held for an
extended time (about 1 hour or more) and then slowly cooled in still
air.
Spheroidization is an annealing process used for high carbon steels
(Carbon > 0.6%) that will be machined or cold formed subsequently.
This is done by one of the following ways:
1. Heat the part to a temperature just below the Ferrite-Austenite
line, line A1 or below the Austenite-Cementite line, essentially
below the 727 ºC (1340 ºF) line. Hold the temperature for a
prolonged time and follow by fairly slow cooling. Or
2. Cycle multiple times between temperatures slightly above and
slightly below the 727 ºC (1340 ºF) line, say for example
between 700 and 750 ºC (1292 - 1382 ºF), and slow cool. Or
3. For tool and alloy steels heat to 750 to 800 ºC (1382-1472 ºF)
and hold for several hours followed by slow cooling.
Teaching
Methodology:
PPT - UNIT II-HEAT TREATMENT
Learning
Resource (page
number)
R4- (44 to 48)

Lesson Title NORMALISING,HARDENINGAND TEMPERING
Lesson concept/
Points/Definitions
Normalising
Applied to some, but not all, engineering steels, normalising can
soften, harden or stress relieve a material, depending on its initial
state. The objective of the treatment is to counter the effects of prior
processes, such as casting, forging or rolling, by refining the existing
non-uniform structure into one which enhances
machinability/formability or, in certain product forms, meets final
mechanical property requirements.
A primary purpose is to condition the steel so that, after subsequent
shaping, a component responds satisfactorily to a hardening operation
(e.g. aiding dimensional stability).
Normalising consists of heating the suitable steel to a temperature
typically in the range 830-950°C (at or above the hardening
temperature of hardening steels, or above the carburising temperature
for carburising steels) and then cooling in air. Heating is usually
carried out in air, so subsequent machining or surface finishing is
required to remove scale or decarburised layers.
Hardening and Tempering
Changing the properties of metals by processes involves heating. It is
used to harden, soften, or modify other properties of materials that
have different structures at low and high temperatures.
The type of transformation depends on the temperature that the
material is heated to, how fast it is heated, how long it is kept heated,
what temperature it is first cooled to, and how fast it is cooled.
(Hardened and quenched)
Followed by a secondary heating stage of a much lower temperature
and a length of time it is held. (Tempering)
Every heat treatable material has specific temperature ranges for
hardening and quenching mediums long with tempering temperatures
to produce the mechanical properties or hardness's required for the
application it has been chosen.
After the hardening treatment is applied, steel is often harder than
needed and is too brittle for most practical uses. Also, severe internal
stresses are set up during the rapid cooling from the hardening
temperature. To relieve the internal stresses and reduce brittleness,
you should temper the steel after it is hardened. Tempering consists of
heating the steel to a specific temperature (below its hardening
temperature), holding it at that temperature for the required length of
time, and then cooling it, usually in still air. The resultant strength,

hardness, and ductility depend on the temperature to which the steel is
heated during the tempering process.
Teaching
Methodology:
PPT - UNIT II- HEAT TREATMENT
Learning
Resource (page
number)
T2- (132)
Lesson Title ISOTHERMAL TRANSFORMATION DIAGRAMS
Lesson concept/
Points/Definitions
Isothermal Transformation Diagrams
Isothermal transformation diagrams (also known as time-temperature-
transformation diagrams) are plots of temperature versus time (usually on
a logarithmic scale).
They are generated from percentage transformation-vs logarithm of time
measurements,and are useful for understanding the transformations of
an alloy steelthat is cooled isothermally.
An isothermal transformation diagram is only valid for one specific
composition of material, and only if the temperature is held constant during
the transformation, and strictly with rapid cooling to that temperature.
Though usually used to represent transformation kinetics for steels, they also
can be used to describe the kinetics of crystallization in ceramic or other
materials.
Time-temperature-precipitation diagrams and time-temperature-
embrittlement diagrams have also been used to represent kinetic changes in
steels.
Isothermal transformation (IT) diagram or the C-curve is associated with
mechanical properties, microconstituents/microstructures, and heat
treatments in carbon steels.
The rate of austenite transforms to a cementite and ferrite mixture can be
explained using the sigmoidal curve; this eutectoid transformation begins
and is represented by the pearlite start (Ps) curve. This transformation is
complete at pearlite finish (Pf )curve.
Nucleation requires an incubation time. The rate of nucleation increases and
the rate of microconstituent growth decreases as the temperature decreases
from the liquidus temperature.
As a result of the transformation, the microconstituents, Pearlite and Bainite,
form; Pearlite forms at higher temperatures and bainite at lower.
Austenite is slightly undercooled when quenched
below Eutectoid temperature. When given more time, stable
microconstituents can form: ferrite and cementite
Teaching
Methodology:
Learning
Resource (page
number)
T2- (232 to 237)
Lesson Title COOLINGCURVES SUPERIMPOSEDON I.T. DIAGRAM,CCR
Lesson concept/
Points/Definitions
Critical Cooling Rate (CCR)

Concept:
Critical cooling rate is that the slowest rate of cooling at which all the
austenite is transformed into 100% martensite.
Critical cooling rate is important when hardening the steels (having
proper carbon content). In order to obtain fully martensitic (a very
hard) structure, the cooling rate must be more than the critical cooling
rate. It is actually the cooling rate (refer figure TTT diagram) that
determines the type of structure which will be obtained on cooling.
Slow cooling will produce a pearlitic structure and higher cooling rate
can form a martensitic structure. The final properties of the steel
component thus cooled will depend upon, therefore, on the magnitude
of cooling rate.
Various factors affecting the critical cooling rate are:
1 Composition of steel
The critical cooling rate varies with the carbon content of the steel.
The critical cooling rate is minimum when carbon is around 0.9%
2) Temperature of hardening
The higher is the quenching (hardening) temperature the more
uniform becomes the austenite, the lower is the critical cooling time
and more will be the critical cooling rate.
3) Purity of steel
The purer is the steel, the lesser will be the critical cooling rate for
quenching.
Teaching
Methodology:
PPT - UNIT II HEAT TREATMENT
Learning
Resource (page
number)
T2- (117 to 125)
Lesson Title HARDENABILITY, JOMINY END QUENCH TEST
Lesson concept/
Points/Definitions
Hardenability, Jominy End Quench Test
It is important to distinguish between hardness and hardenability.
Hardness is a measure of resistance to plastic deformation. Hardenability
may be defined as the ease with which a steel component can be hardened
by martensitic transformation. Hardenability may also be defined as the
depth of hardening produced under the given conditions of cooling.

Hardenability is evaluated by determining the minimum cooling rate
to transform an austenitized steel to a structure that is predominantly or
entirely martensitic.
Hardenability is usually tested by using the Jominy End Quench
Test. In this test the specimen dimensions and test conditions are
standardized.
The specimen is of cylindrical shape with 25.4mm (1 inch) diameter and
approximately 102 mm (4 inch) in length. The specimen is machined with a
shoulder at one end or may be fitted with a detachable collar ring at one end.
The specimen is heated to the austenitic temperature at a constant
temperature for a fixed time and quickly transferred to a fixture that supports
the specimen at its shoulder or collar.
Water at a temperature of 21 to 270
C is sprayed at the bottom end
of the specimen for about 20 minutes.
The pipe carrying the water has an inside diameter of 12.7 mm(1/2
inch). The pressure of the water is adjusted such that the free height of water
is approximately 64mm (2.5 inch). At this pressure,water forms a complete
umbrella shape at the bottom of the specimen.
The cooling rate will be maximum at the quenched end of the
specimen where full hardening occurs and gradually deccreases towards the
air cooled end bf the specimen, at this end the structure obtained is similar to
that produced by normalising. The specimen has urdergone all possible rates
of cooling from water quenching (rapid cooling) to air cooling (slow
cooling).
Since the Jominy end quench test is standardised, any other
specimen of the same composition will show the same results. It is possible
to compare the hardenability of other steels for their microstructure at
similar locations from the quenched end. After the completion of quenching,
two surfaces are ground flat (about 1.6mm depth) opposite to each other
along the entire length of the specimen. The hardness (Rc-Rockwell or
VPN-Vickers pyramid hardness) is measured at regular distance of every 1.6
mm (1/16 inch) from the quenched end.
Teaching
Methodology:
Learning
Resource (page
number)
T2- (145 to 153)
Lesson Title AUSTEMPERING, MARTEMPERING
Lesson concept/
Points/Definitions Austempering, Martempering
Austempering:
Austempering is the cooling of the austenitized steel with a rate more
than the critical cooling rate in a molten salt bath held at a
temperature between the nose of the TTT diagram and Ms
temperature. i.e., in the bainite region. The component is held at that
temperature for a sufficient period of time till the entire structure in
the component completely transforms to bainite. It is then cooled to
room temperature at a desired rate. The figure has been drawn for a

hypoeutectoid steel.
However there are certain disadvantages by performing
austempering.
1) The hardness obtained is not as high as that obtained through
martensitic transformation as in hardening.
2) In austempering we do not perform tempering operation,
however steels which are hardened by quenching are always
tempered and hence the desired properties can be obtained by
selecting suitable tempering temperatures. This is not possible
in austempering.
3) The cooling rate in austempering is greater than the critical
cooling rate, hence only steels which have good hardenability
properties can be austempered. Components made of high
carbon steels and alloy steels have good hardenability.
4) The soaking time or holding time for the transformation to
take place is more, hence this is a more expensive process.
Teaching
Methodology:
Learning
Resource (page
number)
T2- (304)
Lesson Title MARTEMPERINGOR MARQUENCHINGOR INTERRUPTED
QUENCHING
Lesson concept/
Points/Definitions
Martempering or Marquenching or Interrupted quenching
Martempering is a hardening process.
The name martempering is an abbreviation for martensite
tempering. Hence the name martempering is a misnomer.
In this process the austenitized steel is rapidly cooled to
avoid the nose region of the TTT diagram to a temperature between
the Ms (Martensite Start) and Mf (Martensite finish) region. The
component is held or soaked at this temperature for a sufficient time
till the entire component reaches the soaking temperature. It should
not be held for a very long time otherwise there will be a formation of
bainite. The component is cooled to room temperature in air or oil.
Martensitic structure is obtained after the completion of

transformation.
Teaching
Methodology:
Learning
Resource (page
number)
R4- (155 to 163)
Lesson Title CASE HARDENING
Lesson concept/
Points/Definitions
Case Hardening
Case hardening / Surface hardening
In engineering practice it is often necessary for parts to have
a hard, wear resisting
skin (outer surface) with a tough impact resisting core (inner surface).
No carbon steels even alloy steels posses both the above requirements.
So some methods have been developed to obtain this combination and
are called surface hardening or case hardening processes.
Generally Usedcase hardening are:
Carburizing, Cyaniding, Nitriding, Carbo Nitriding, Flame hardening,
Induction hardening, Electron beam hardening, Laser beam
hardening, Metallic cementation and Boriding
Teaching
Methodology:
Learning
Resource (page
number)
T2- (101,119)
Lesson Title CARBURISING,NITRIDING,CYANIDING, CARBONITRIDING,
FLAME AND INDUCTION HARDENING.
Lesson concept/
Points/Definitions
Carburising, Nitriding, Cyaniding, Carbonitriding, Flame and
Induction Hardening.
Carburizing
Carburizing is a process of enriching or saturating the surface layers

of steel with
Carbon. The depth of case obtained in components depends on the
time temperature, and type of carburizer used in the process.
There are three methods of carburizing namely
1) Pack or solid carburizing
2) Liquid carburizing (Liquid carburizing uses a molten potassium
cyanide salt
bath at a temp of 8500C and immersed in that bath)
3) Gas carburizing.
Pack carburizing or Solid carburizing
In this process components to be case hardened are packed
into a steel box along with carburizing and energizing mixture. The
mixture consists of a solid carburizer normally charcoal of 40 to
70%,barium carbonate of 20-25%, sodium carbonate of 3 to 12% (to
intensify the process) and CaCo3 of 3 to 5% (to prevent the carburizer
particles from caking). The box is covered and the lid is tightly sealed
with fire clay (to prevent the entry or escape of gases).
The box is then placed in a furnace and heated to a
temperature of 900 to 9800C for 6 to 72 hours. [The time depends on
case depth and temperature]. During heating the charcoal releases Co
gas which reacts with the metal and releases the desired carbon which
is absorbed in the austenite of the metal surface.
Gas carburizing
The parts to be gas carburized are kept in a tightly sealed
furnace chamber filled with a carburizing gas. Usually, the
carburizing gas is made to flow through the chambers at a given
speed. Any one of the saturated hydro carbons like methane (CH4),
ethane (C6H6),propane (C3H8) butane (C4H10) can be used for this
process. But Natural (having 96% CH4) is more commonly used. A
liquid hydrocarbon (Kerosene, benzene etc) is supplied drop wise into
the air tight furnace to activate the process.
Liquid carburizing
The process is suitable for case hardening small components. In this
both carbon and nitrogen are added to the steel surface. This is quite
similar to cyaniding. [except that the steel surface is higher in carbon

and lower in nitrogen ].
In this process steel parts are immersed for I to 2 hours in a molten
cyanide salt bath [20 to 50% sodium cyanide, 30 to 40% sodium
carbonate and 18 to 30% sodium chloride ] kept at a temperature of
900o to 950oC. Now both carbon and nitrogen are added to the surface
of steel; producing a harder case than by gas carburizing. Case depth
obtained in liquid carburizing is very small, i.e., from 0.08 to 1.0 mm.
Nitriding
Nitriding is the process of diffusion saturation of certain alloy
steel surface with nitrogen. Alloying elements in steels like Al, Cr, V
and Mo would form very hard nitrides when they combine with
nitrogen. This is the basic principal of nitriding.
Nitriding is done at 5000-6000C. The parts to be nitrided are placed in
a tightly closed box which is installed in a heating furnace. Gaseous
ammonia is supplied to the box at a definite flow rate. Now atomic
nitrogen is formed due to the dissociation of NH3 by the reaction
NH3 = 3H + N
The Nitrogen gets diffused in the metal and forms very hard nitrides.
Nitriding is employed to increase the hardness, wear resistance,
endurance limit and corrosion resistance of steels. The process is
suitable for link pins, shafts, pump components, etc.
Cyaniding
It is also called as liquid carbonitriding. Cyaniding is a process of
diffusion saturation of steel with carbon and nitrogen at the same
time. In this process the parts to be case hardened are immersed in a
bath of molten cyanide bath. [The bath contains 20 – 25% NaCN, 25-
50%Nacl, and 25-50%Na2Co3] which is at a temperature slightly
above AC1 range.
The time of holding depends on the depth of case. Similar to
liquid carburzing carbon and nitrogen are absorbed into the steel
surface. [Less carbon and more Nitrogen]. Cyanided layers have a
higher wear resistance, higher hardness and higher corrosion
resistance as compared to carburized layers. It also increases fatigue
strength. Case depth is upto 0.3mm
Cyanides are poisonous therefore the process should be
carried out in special rooms and with strict observance of safety rules.

Flame hardening or torch hardening
This method involves rapidly heating the surface of the steel
or cast iron to a temperature above its upper critical temperature by
using an oxyacetylene flame torch, followed by water spray
quenching or by immersing the component into a quenching medium
in order to transform austenite to martensite.
Induction hardening
Heating steel or cast iron by means of high frequency
electric current is induction hardening. The principle of induction is
that when a component is placed in a varying magnetic field an eddy
current is induced in it. This eddy current produced is used to heat the
component. The component heated by induction is then quenched.
Teaching
Methodology:
Learning
Resource (page
number)
T1- (578,579)
Lesson Title EFFECT OF ALLOYINGELEMENTS
Lesson concept/
Points/Definitions
Effect of Alloying Elements on Steel (Mn, Si, Cr, Mo, V, Ti & W)
Alloying is changing chemical composition of steel by adding
elements with purpose to improve its properties as compared to the
plane carbon steel.
Characteristics of alloying elements
Manganese (Mn) – improves hardenability, ductility and wear
resistance. Mn eliminates formation of harmful iron sulfides,
increasing strength at high temperatures.
Nickel (Ni) – increases strength, impact strength and toughness,
impart corrosion resistance in combination with other elements.
Chromium (Cr) – improves hardenability, strength and wear
resistance, sharply increases corrosion resistance at high
concentrations (> 12%).
Tungsten (W) – increases hardness particularly at elevated
temperatures due to stable carbides, refines grain size.
Vanadium (V) – increases strength, hardness, creep resistance and
impact resistance due to formation of hard vanadium carbides, limits
grain size.
Molybdenum (Mo) – increases hardenability and strength
particularly at high temperatures and under dynamic conditions.
Silicon (Si) – improves strength, elasticity, acid resistance and
promotes large grain sizes, which cause increasing magnetic
permeability.
Titanium (Ti) – improves strength and corrosion resistance, limits
austenite grain size.
Cobalt (Co) – improves strength at high temperatures and magnetic

permeability.
Zirconium (Zr) – increases strength and limits grain sizes.
Boron (B) – highly effective hardenability agent, improves
deformability and machinability.
Copper (Cu) – improves corrosion resistance.
Aluminum (Al) – deoxidizer, limits austenite grains growth
Teaching
Methodology:
PPT - UNIT III-FERROUS AND NON FERROUS
Learning
Resource (page
number)
T1- (162-166)
Lesson Title CHARACTERISTICS OF ALLOYINGELEMENTS
Lesson concept/
Points/Definitions
Effect of Alloying Elements on Steel (Mn, Si, Cr, Mo, V, Ti & W)
Alloying is changing chemical composition of steel by adding
elements with purpose to improve its properties as compared to the
plane carbon steel.
Characteristics of alloying elements
Manganese (Mn) – improves hardenability, ductility and wear
resistance. Mn eliminates formation of harmful iron sulfides,
increasing strength at high temperatures.
Nickel (Ni) – increases strength, impact strength and toughness,
impart corrosion resistance in combination with other elements.
Chromium (Cr) – improves hardenability, strength and wear
resistance, sharply increases corrosion resistance at high
concentrations (> 12%).
Tungsten (W) – increases hardness particularly at elevated
temperatures due to stable carbides, refines grain size.
Vanadium (V) – increases strength, hardness, creep resistance and
impact resistance due to formation of hard vanadium carbides, limits
grain size.
Molybdenum (Mo) – increases hardenability and strength
particularly at high temperatures and under dynamic conditions.
Silicon (Si) – improves strength, elasticity, acid resistance and
promotes large grain sizes, which cause increasing magnetic
permeability.
Titanium (Ti) – improves strength and corrosion resistance, limits

austenite grain size.
Cobalt (Co) – improves strength at high temperatures and magnetic
permeability.
Zirconium (Zr) – increases strength and limits grain sizes.
Boron (B) – highly effective hardenability agent, improves
deformability and machinability.
Copper (Cu) – improves corrosion resistance.
Aluminum (Al) – deoxidizer, limits austenite grains growth
Teaching
Methodology:
Learning
Resource (page
number)
T2- (235to 237)
Lesson Title STAINLESS AND TOOL STEELS
Lesson concept/
Points/Definitions
Stainless and Tool Steels
In metallurgy, stainless steel, also known as inox
steel or inox from French "inoxydable", is defined as a steel alloy with
a minimum of 10.5%[1] to 11% chromium content by mass.
Stainless steel does not readily corrode, rust or stain with
water as ordinary steel does, but despite the name it is not fully stain-
proof, most notably under low oxygen, high salinity, or poor
circulation environments.[3] It is also called corrosion-resistant
steel or CRESwhen the alloy type and grade are not detailed,
particularly in the aviation industry. There are different grades and
surface finishes of stainless steel to suit the environment the alloy
must endure. Stainless steel is used where both the properties of steel
and resistance to corrosion are required.
Stainless steel differs from carbon steel by the amount
of chromium present. Unprotected carbon steel rusts readily when
exposed to air and moisture. This iron oxide film (the rust) is active
and accelerates corrosion by forming more iron oxide, and due to the
dissimilar size of the iron and iron oxide molecules (iron oxide is
larger) these tend to flake and fall away. Stainless steels contain
sufficient chromium to form a passive film of chromium oxide, which
prevents further surface corrosion and blocks corrosion from
spreading into the metal's internal structure, and due to the similar size

of the steel and oxide molecules they bond very strongly and remain
attached to the surface.[4]
Tool steel
Tool steel refers to a variety of carbon and alloy steels that
are particularly well-suited to be made into tools. Their suitability
comes from their distinctive hardness, resistance to abrasion, their
ability to hold a cutting edge, and/or their resistance to deformation at
elevated temperatures (red-hardness). Tool steel is generally used in
a heat-treated state. Many high carbon tool steels are also more
resistant to corrosion due to their higher ratios of elements such as
vanadium
With a carbon content between 0.7% and 1.5%, tool steels
are manufactured under carefully controlled conditions to produce the
required quality. The manganese content is often kept low to
minimize the possibility of cracking during water quenching.
However, proper heat treating of these steels is important for adequate
performance, and there are many suppliers who provide tooling
blanks intended for oil quenching.
Tool steels are made to a number of grades for different
applications. Choice of grade depends on, among other things,
whether a keen cutting edge is necessary, as in stamping dies, or
whether the tool has to withstand impact loading and service
conditions encountered with such hand tools as axes, pickaxes,
and quarrying implements. In general, the edge temperature under
expected use is an important determinant of both composition and
required heat treatment. The higher carbon grades are typically used
for such applications as stamping dies, metal cutting tools, etc.
Tool steels are also used for special applications
like injection molding because the resistance to abrasion is an
important criterion for a mold that will be used to produce hundreds
of thousands of parts.
Teaching
Methodology:
Learning
Resource (page
number)
T2- (159 to 163)
Lesson Title HSLA - MARAGINGSTEELS
Lesson
concept/
HSLA - Maraging Steels

Points/Definiti
ons
High-strength low-alloy steel (HSLA) is a type of alloy steel that
provides better mechanical properties or greater resistance to corrosion
than carbon steel. HSLA steels vary from other steels in that they are not made to
meet a specific chemical composition but rather to specific mechanical properties.
They have a carbon content between 0.05–0.25% to retain formability
and weldability. Other alloying elements include up to 2.0% manganese and small
quantities
of copper, nickel, niobium, nitrogen, vanadium, chromium,molybdenum, titanium,
calcium, rare earth elements, or zirconium.[1][2] Copper, titanium, vanadium, and
niobium are added for strengthening purposes.[2] These elements are intended to
alter the microstructure of carbon steels, which is usually a ferrite-
pearliteaggregate, to produce a very fine dispersion of alloy carbides in an almost
pure ferrite matrix. This eliminates the toughness-reducing effect of a pearlitic
volume fraction yet maintains and increases the material's strength by refining the
grain size, which in the case of ferrite increases yield strength by 50% for every
halving of the mean grain diameter. Precipitation strengthening plays a minor role,
too. Their yield strengths can be anywhere between 250–590 megapascals
(36,000–86,000 psi). Because of their higher strength and toughness HSLA steels
usually require 25 to 30% more power to form, as compared to carbon steels.[2]
Copper, silicon, nickel, chromium, and phosphorus are added to
increase corrosion resistance. Zirconium, calcium, and rare earth elements are
added for sulfide-inclusion shape control which increases formability. These are
needed because most HSLA steels have directionally sensitive properties.
Formability and impact strength can vary significantly when tested longitudinally
and transversely to the grain. Bends that are parallel to the longitudinal grain are
more likely to crack around the outer edge because it experiences tensile loads.
This directional characteristic is substantially reduced in HSLA steels that have
been treated for sulfide shape control.[2]
They are used in cars, trucks, cranes, bridges, roller coasters and
other structures that are designed to handle large amounts of stressor need a good
strength-to-weight ratio.[2] HSLA steels are usually 20 to 30% lighter than a
carbon steel with the same strength.[3][4]

HSLA steels are also more resistant to rust than most carbon
steels because of their lack of pearlite – the fine layers of ferrite (almost pure iron)
and cementite in pearlite.[citation needed] HSLA steels usually have densities of around
7800 kg/m³.[5]
Maraging steels (a portmanteau of "martensitic" and "aging")
are steels (iron alloys) which are known for possessing superior strength and
toughness without losing malleability, although they cannot hold a good cutting
edge. Aging refers to the extended heat-treatment process. These steels are a
special class of low-carbon ultra-high-strength steels which derive their strength
not from carbon, but from precipitation of inter-metallic compounds. The principal
alloying element is 15 to 25 wt.% nickel.[1] Secondary alloying elements are added
to produce intermetallic precipitates, which include cobalt, molybdenum,
and titanium.[1] Original development was carried out on 20 and 25 wt.% Ni steels
to which small additions of Al, Ti, and Nb were made.
The common, non-stainless grades contain 17–19 wt.% nickel, 8–12 wt.% cobalt,
3–5 wt.% molybdenum, and 0.2–1.6 wt.% titanium. Addition of chromium
produces stainless grades resistant to corrosion. This also indirectly
increases hardenability as they require less nickel: high-chromium, high-nickel
steels are generally austenitic and unable to transform to martensite when heat
treated, while lower-nickel steels can transform to martensite. Alternative variants
of Ni-reduced maraging steels are based on alloys of Fe and Mn plus minor
additions of Al, Ni, and Ti where compositions between Fe-9wt.% Mn to Fe-
15wt.% Mn have been used. The Mn has a similar effect as Ni, i.e. it stabilizes the
austenite phase. Hence, depending on their Mn content, Fe-Mn maraging steels
can be fully martensitic after quenching them from the high temperature austenite
phase or they can contain retained austenite. The latter effect enables the design of
maraging-TRIP steels where TRIP stands for Transformation-Induced-Plasticity.[2]
Teaching
Methodology:
Learning
Resource
(page
number)
T2- (303 to 304)
Lesson Title CAST IRONS - GREY, WHITE MALLEABLE, SPHEROIDAL

Lesson concept/
Points/Definitions
Cast Irons - Grey, White Malleable, Spheroidal
Cast iron is iron or a ferrous alloy which has been
heated until it liquefies, and is then poured into a mould to solidify. It
is usually made from pig iron. The alloy constituents affect its colour
when fractured: white cast iron has carbide impurities which allow
cracks to pass straight through. Grey cast iron, or grey iron, has
graphitic flakes which deflect a passing crack and initiate countless
new cracks as the material breaks.
Carbon (C) and silicon (Si) are the main alloying
elements, with the amount ranging from 2.1 to 4 wt% and 1 to 3 wt%,
respectively. Iron alloys with less carbon content are known as steel.
While this technically makes these base alloys ternary Fe-C-Si alloys,
the principle of cast iron solidification is understood from
the binary iron-carbon phase diagram. Since the compositions of most
cast irons are around the eutectic point of the iron-carbon system, the
melting temperatures closely correlate, usually ranging from 1,150 to
1,200 °C (2,102 to 2,192 °F), which is about 300 °C (572 °F) lower
than the melting point of pure iron.
Cast iron tends to be brittle, except for malleable cast
irons. With its relatively low melting point, good fluidity, castability,
excellent machinability, resistance to deformation and wear
resistance, cast irons have become an engineering material with a
wide range of applications and are used in pipes, machines
and automotive industry parts, such as cylinder heads (declining
usage), cylinder blocksand gearbox cases (declining usage). It is
resistant to destruction and weakening by oxidation (rust).
Grey cast iron is characterised by its graphitic
microstructure, which causes fractures of the material to have a grey
appearance. It is the most commonly used cast iron and the most
widely used cast material based on weight. Most cast irons have a
chemical composition of 2.5 to 4.0% carbon, 1 to 3% silicon, and the
remainder is iron. Grey cast iron has less tensile strength and shock
resistance than steel, but its compressive strength is comparable to
low and medium carbon steel.
It is the iron that displays white fractured surface due to
the presence of cementite. With a lower silicon content and faster
cooling, the carbon in white cast iron precipitates out of the melt as
the metastable phase cementite, Fe3C, rather than graphite. The
cementite which precipitates from the melt forms as relatively large
particles, usually in a eutectic mixture, where the other phase
is austenite (which on cooling might transform to martensite). These

eutectic carbides are much too large to provide precipitation
hardening (as in some steels, where cementite precipitates might
inhibit plastic deformation by impeding the movement
of dislocations through the ferrite matrix). Rather, they increase the
bulk hardness of the cast iron simply by virtue of their own very high
hardness and their substantial volume fraction, such that the bulk
hardness can be approximated by a rule of mixtures. In any case, they
offer hardness at the expense of toughness. Since carbide makes up a
large fraction of the material, white cast iron could reasonably be
classified as acermet. White iron is too brittle for use in many
structural components, but with good hardness and abrasion resistance
and relatively low cost, it finds use in such applications as the wear
surfaces (impeller and volute) of slurry pumps, shell liners and lifter
bars in ball mills and autogenous grinding mills, balls and rings
in coal pulverisers, and the teeth of abackhoe's digging bucket
(although cast medium-carbon martensitic steel is more common for
this application).
High-chromium white iron alloys allow massive castings
(for example, a 10-tonne impeller) to be sand cast, i.e., a high cooling
rate is not required, as well as providing impressive abrasion
resistance.
Malleable iron starts as a white iron casting that is then heat treated at
about 900 °C (1,650 °F). Graphite separates out much more slowly in
this case, so that surface tension has time to form it into spheroidal
particles rather than flakes. Due to their lower aspect ratio, spheroids
are relatively short and far from one another, and have a lower cross
section vis-a-vis a propagating crack or phonon. They also have blunt
boundaries, as opposed to flakes, which alleviates the stress
concentration problems faced by grey cast iron. In general, the
properties of malleable cast iron are more like mild steel. There is a
limit to how large a part can be cast in malleable iron, since it is made
from white cast iron.
A more recent development is nodular or ductile cast iron. Tiny
amounts of magnesium or cerium added to these alloys slow down the
growth of graphite precipitates by bonding to the edges of the graphite
planes. Along with careful control of other elements and timing, this
allows the carbon to separate as spheroidal particles as the material
solidifies. The properties are similar to malleable iron, but parts can
be cast with larger sections
Teaching
Methodology:
Learning
Resource (page
number)
T2- (235)

Lesson Title GRAPHITE,ALLOY CAST IRONS,COPPER AND COPPER ALLOYS
Lesson concept/
Points/Definitions
Graphite, Alloy Cast Irons, Copper and Copper Alloys
Graphite is the most stable form of carbon under standard conditions.
Therefore, it is used in thermochemistry as the standard state for
defining the heat of formation of carbon compounds. Graphite may be
considered the highest grade of coal, just above anthracite and
alternatively called meta-anthracite, although it is not normally used
as fuel because it is difficult to ignite.
Cast iron containing alloying elements (usually nickel or chromium
or copper or molybdenum) to increase the strength or facilitate heat
treatment
Copper is a chemical element with the
symbol Cu (from Latin: cuprum) and atomic number 29. It is
a ductile metal with very high thermal and electrical conductivity.
Pure copper is soft and malleable; a freshly exposed surface has a
reddish-orange color. It is used as a conductor of heat and electricity,
a building material, and a constituent of various metal alloys.
Copper alloys are metal alloys that have copper as their principal
component. They have high resistance against corrosion. The best
known traditional types are bronze, where tinis a significant addition,
and brass, using zinc instead
Teaching
Methodology:
Learning
Resource (page
number)
R4- (297-302)
Lesson Title Brass,Bronzeand Cupronickel
Lesson concept/
Points/Definitions
There are more than 400 copper alloys, each with a unique combination of
properties, to suit many applications, manufacturing processes and
environments.
Pure copper has the best electrical and thermal conductivity of any
commercial metal. Today, over half of the copper produced is used in
electrical and electronic applications and this leads to a convenient
classification of the types of copper into electrical (high conductivity) and
non-electrical (engineering).
Copper forms alloys more freely than most metals and with a wide range of
alloying elements to produce the following alloys:
Brass is the generic term for a range of copper-zinc alloys with differing
combinations of properties, including strength, machinability, ductility,
wear-resistance, hardness, colour, antimicrobial, electrical and thermal
conductivity, and corrosion-resistance.
Bronze alloys are made from copper and tin, and were the first to be

developed about four thousand years ago. They were so important that they
led to a period in time being named the Bronze Age.
Gunmetals are alloys of copper with tin, zinc and lead and have been used
for at least 2000 years due to their ease of casting and good strength and
corrosion resistance.
Copper-nickel alloys have excellent resistance to marine corrosion and
biofouling. The addition of nickel to copper improves strength and
corrosion resistance,but good ductility is retained.
Nickel silver alloys are made from copper, nickel and zinc, and can be
regarded as special brasses. They have an attractive silvery appearance rather
than the typical brassy colour.
Teaching
Methodology:
PPT - UNIT III
Learning
Resource (page
number)
T1- (146 to 148)
Lesson Title ALUMINUM AND AL-CU ALLOY
Lesson concept/
Points/Definitions
Aluminium (or aluminum) is a chemical element in the boron group with
symbol Al and atomic number 13. It is a silvery white, soft, ductile metal.
Aluminium is the third most abundant element (after oxygen and silicon),
and the most abundant metal, in theEarth's crust. It makes up about 8% by
weight of the Earth's solid surface. Aluminium metal is so chemically
reactive that native specimens are rare and limited to
extreme reducing environments. Instead, it is found combined in over 270
different minerals. The chief ore of aluminium is bauxite.
Aluminium is remarkable for the metal's low density and for its ability to
resist corrosion due to the phenomenon of passivation. Structural
components made from aluminium and its alloys are vital to
the aerospace industry and are important in other areas oftransportation and
structural materials. The most useful compounds of aluminium, at least on a
weight basis, are the oxides andsulfates.
Teaching
Methodology:
PPT - UNIT III
Learning
Resource (page
number)
R4- (76,77)
Lesson Title PRECIPITATIONHARDENING

Lesson concept/
Points/Definitions
Precipitation hardening, also called age hardening, is a heat
treatment technique used to increase the yield strength
of malleable materials, including most structural alloys of
aluminium, magnesium, nickel, titanium, and some stainless steels.
In superalloys, it is known to cause yield strength anomaly providing
excellent high temperature strength.
Precipitation hardening relies on changes in
solid solubility with temperature to produce fine particles of an
impurity phase, which impede the movement of dislocations, or defects in
a crystal's lattice. Since dislocations are often the dominant carriers
of plasticity, this serves to harden the material. The impurities play the same
role as the particle substances in particle-reinforced composite materials.
Just as the formation of ice in air can produce clouds, snow, or hail,
depending upon the thermal history of a given portion of the
atmosphere, precipitation in solids can produce many different sizes of
particles, which have radically different properties. Unlike
ordinary tempering, alloys must be kept at elevated temperature for hours to
allow precipitation to take place. This time delay is called aging.
Teaching
Methodology:
PPT - UNIT III
Learning
Resource (page
number)
R4-213;T2- (289)
Lesson Title BEARINGALLOYS.
Lesson concept/
Points/Definitions
Babbitt, also called Babbitt metal or bearing metal, is any of
severalalloys used for the bearing surface in a plain bearing.
The original Babbitt metal was invented in 1839 by Isaac
Babbitt[1] in Taunton, Massachusetts,USA.
Babbitt metal is most commonly used as a thin surface layer in a complex,
multi-metal structure, but its original use was as a cast-in-place bulk bearing
material. Babbitt metal is characterized by its resistance to galling. Babbitt
metal is soft and easily damaged, which suggests that it might be unsuitable
for a bearing surface. However, its structure is made up of small
hard crystals dispersed in a softer metal, which makes it a metal matrix
composite. As the bearing wears, the softer metal erodes somewhat, which
creates paths for lubricant between the hard high spots that provide the
actual bearing surface. When tin is used as the softer metal, friction causes
the tin to melt and function as a lubricant, which protects the bearing from
wear when other lubricants are absent.
Internal combustion engines use Babbitt metal which is primarily tin-based
because it can withstand cyclic loading. Lead-based Babbitt tends to work-
harden and develop cracks but it is suitable for constant-turning tools such as
sawblades.

Teaching
Methodology:
PPT - UNIT III
Learning
Resource (page
number)
T2- (305-307);R4-218
Lesson Title POLYMERS
Lesson concept/
Points/Definitions
A polymer is a large molecule (macromolecule) composed of
repeating structural units. These subunits are typically connected by
covalent chemical bonds. Although the term polymer is sometimes
taken to refer to plastics, it actually encompasses a large class of
natural and synthetic materials with a wide variety of properties.
Because of the extraordinary range of properties of polymeric
materials,[2] they play an essential and ubiquitous role in everyday
life.[3] This role ranges from familiar synthetic plastics and elastomers
to natural biopolymers such as nucleic acids and proteins that are
essential for life.
Natural polymeric materials such as shellac, amber, and natural rubber have
been used for centuries. A variety of other natural polymers exist, such as
cellulose, which is the main constituent of wood and paper. The list of
synthetic polymers includes synthetic rubber, Bakelite, neoprene, nylon,
PVC, polystyrene, polyethylene, polypropylene, polyacrylonitrile, PVB,
silicone, and many more.
Most commonly, the continuously linked backbone of a polymer used
for the preparation of plastics consists mainly of carbon atoms. A
simple example is polyethylene, whose repeating unit is based on
ethylene monomer. However, other structures do exist; for example,
elements such as silicon form familiar materials such as silicones,
examples being silly putty and waterproof plumbing sealant. Oxygen
is also commonly present in polymer backbones, such as those of
polyethylene glycol, polysaccharides (in glycosidic bonds), and DNA
(in phosphodiester bonds).
Polymers are studied in the fields of polymer chemistry, polymer physics,
and polymer science
Teaching
Methodology:
PPT - UNIT IV
Learning
Resource (page
number)
T1- (183)
Lesson Title TYPES OF POLYMER
Lesson concept/
Points/Definitions
Polymer science is a broad field that includes many types of materials
which incorporate long chain structures with many repeated units. One

useful way of categorising polymers for the requirements of electronic
assembly is by functional behaviour. In the strictest sense these categories
are not fixed, or even particularly precise, and you should be aware that
some materials can fit into more than one category:
Elastomers are flexible or ‘rubbery’ materials which can readily be
deformed, and return rapidly to almost their original shape and size once
released from stress, thus making them able to form reliable seals. Natural
and synthetic rubbers are common examples of elastomers
Plastics are materials which can be shaped or moulded under appropriate
conditions of temperature and pressure, and then hold their shape. In
contrast to elastomers, plastics have a greater stiffness and lack reversible
elasticity
Elastomers
ASTM D-156611 defines an elastomer as a ‘macromolecular material that
returns rapidly to approximately the initial dimensions and shape after
substantial deformation by a weak stress and release of the stress.’ Such
elongations typically exceed 100%.
Elastomers have three main functions in electronic assemblies:
to form an environmental seal
to provide mechanical strain relief
to give a means of conducting heat away from sources within the assembly.
Although used for many centuries in its raw form, a significant step forward
was made when Charles Goodyear succeeded in ‘vulcanising’ natural rubber
by heating it with sulphur to induce what is now understood to be cross-
linking. The significance of the great performance improvement resulting
from this treatment has led to the term ‘vulcanisation’ often being loosely
used to describe the cross-linking of any elastomer.
Elastomers consist of long chain-like molecules, linked together to form a
three dimensional network. Typically, an average of about 1 in 100
molecules are cross-linked: when this number rises to about 1 in 30, the
material becomes more rigid and brittle. Most elastomers are thermoset
materials, and cannot be remoulded, an exception being the class of
materials known as ‘thermoplastic elastomers’.
Plastics
‘Plastic’ is a term which can cover a wide range of polymer materials, all of
which can be moulded, for example to produce the body of a QFP
component, the casing for a computer keyboard, the hand set of a mobile
telephone or the encapsulant cover for a PLCC.
There are two main groups of plastic polymers, thermoplastics and
thermosets:
Thermoplastics
Thermoplastics are supplied fully polymerised and remain permanently
fusible, melting when exposed to sufficient heat, and potentially they can be
recycled and reused.
Examples of thermoplastics are polyethylene, poly(vinyl chloride),
polystyrene, nylon, cellulose acetate, acetal, polycarbonate, poly(methyl
methacrylate), and polypropylene.
Thermosets
A thermoset material is produced by a chemical reaction which has two
stages. The first results in the formation of long chain-like molecules similar
to those present in thermoplastics, but still capable of further reaction. This

second stage of inter-linking the long molecules takes place at the point of
use and often under the application of heat and pressure.
Since the cross-linking of the molecules is by strong chemical bonds,
thermoset materials are characteristically quite rigid and their mechanical
properties are not heat sensitive. Once cured, thermosets cannot again be
softened by applying heat: if excess heat is applied to these materials they
will char and degrade – as with eggs, once hard-boiled, they cannot be
softened! Examples of thermosets are phenol formaldehyde, melamine
formaldehyde, urea formaldehyde, epoxies, and some polyesters.
Adhesives
Adhesives can be classified by the method used for curing, and a number of
different mechanisms have been developed to suit different applications:
Anaerobic adhesives are single-component materials which cure at room
temperature when deprived of contact with oxygen. The curing component
in the adhesive will not react with the adhesive as long as it is in contact
with oxygen. The capillary action of this type of liquid adhesive carries it
into even the smallest gaps to fill the joint.
In ultraviolet curing adhesives, the chemicals which would initiate curing
are present, but are bound together and are inactive until exposed to UV
light. The degree of cure depends on the UV intensity, and in some
applications light may be physically blocked from reaching the polymer. In
order to resolve this ‘shadowing effect’ problem, UV curing adhesives may
have secondary curing activation systems, often using heat to ensure that the
cure is complete.
Adhesive types
The lack of a detailed understanding of the adhesion process has not
hindered progress in developing very strong adhesives for most materials.
The only problem is that the wide range of chemical structures makes it
impossible to produce an adhesive which is compatible with all polymers. It
is always prudent to check recommendations on suitable adhesives and
surface preparation with the material manufacturers.
There are two main classes of adhesive for polymeric materials:
Solvent adhesives, which may be either a pure solvent which attacks the
surfaces to be joined so that they fuse together, or a solvent containing some
of the adherend material. This approach is used for polymers such as
polystyrene and polymethyl methacrylate, the choice of solvent depending
on practical issues such as the rate of evaporation
Organic adhesives based on rubbers or polymeric materials, which may be
thermoplastic or thermosetting in nature.
The most versatile range of organic adhesives is that based on epoxy resins,
and these are particularly widespread in electronics, although they are
relatively expensive. The major advantages of epoxy adhesives are that:
They can be formulated to work well over a very wide temperature range
Epoxies have excellent resistance to moisture and chemicals
Shrinkage on cure is negligible, so that residual strains in the joint are small
Creep of the cured material is low
Epoxies can be cured at room or lower temperatures, although those cured at
elevated temperatures are stronger.
There are however,the disadvantages that:
Care is needed when handling uncured epoxy resins
The shelf life of some formulations is limited

High temperature strength can only be achieved by sacrificing ductility.
Epoxy adhesives are sold either as two-part adhesives, where the epoxy
resin is mixed with a catalyst just before use, or single-part materials, where
the catalyst is incorporated during manufacture. Single-part adhesives are
generally less reactive, needing to be heat-cured, and often require
refrigerated storage to increase storage life.
Other adhesives you may encounter are:
Nitrile rubber adhesives: usually copolymers of butadiene and acrylonitrile,
these are good adhesives in their own right, but also combine with phenolic
resins to produce very good structural adhesives
Resorcinol adhesives are particularly good for bonding thermosetting
plastics, but with a few exceptions (ABS, nylon, acrylic) are not suitable for
thermoplastics
‘Tailoring’ polymers
The range of polymer materials available is enormous, as slight changes in
the chemical make-up of the monomers or the conditions of polymerisation
can result in dramatic changes in the material characteristics of the end of
processed polymer.
Polyethylene is an example of a polymer which can be used in a wide
variety of applications because it can be produced with different forms and
structures. The first to be commercially exploited was called low density
polyethylene (LDPE), which is characterised by a high degree of branching,
which forces the molecules to be packed rather loosely. The resulting low
density material is soft and pliable and has applications ranging from plastic
bags and textiles to electrical insulation.
By contrast, high density (HDPE) or linear polyethylene demonstrates little
or no branching, so that the molecules are tightly packed and the plastic can
be used in applications where rigidity is important, such as plastic tubing
and bottle caps. Other forms of this material include high and ultra-high
molecular weight polyethylenes (HMW; UHMW), which are used in
applications where extremely tough and resilient materials are needed.
New materials can also be tailored by combining monomers with desirable
properties. In some cases, these combinations are just physically mixed
polymers, but more typically new ‘co-polymers’ are produced. Some types
have a random structure of the constituent monomers, others may have a
regular, repeating structure of the different materials:
A ‘block’ copolymer is made with blocks of monomers of the same type
A ‘graft’ copolymer has a main chain polymer built with one type of
monomer, and branches made up of other monomers.
Nylon is an example of a common ‘alternating copolymer’ with two
different monomers alternating along the chain. One useful material, which
is in fact a ‘terpolymer’, is ABS. This is a combination of three monomers:
acrylonitrile, butadiene and styrene,in varying proportions depending on the
application. A rigid but tough material, it is used for water pipes,
refrigerators and Lego bricks!
Teaching
Methodology:
PPT - UNIT IV
Learning
Resource (page
number)
T1- (347)

Lesson Title COMMODITY AND ENGINEERINGPOLYMERS
Lesson concept/
Points/Definitions
Commodity plastics are plastics that are used in high volume and wide range
of applications, such as film for packaging, photographic and magnetic tape,
clothing, beverage and trash containers and a variety of household products
where mechanical properties and service environments are not critical. Such
plastics exhibit relatively low mechanical properties and are of low cost. The
range of products includes Plates, Cups, Carrying Trays, Medical Trays,
Containers, Seeding Trays, Printed Material and other disposable items.
Examples of commodity plastics
are polyethylene, polypropylene, polystyrene, polyvinyl
chloride, polymethyl methacrylate, polyethylene terephthalate and more.
Engineering polymers are materials with exceptional mechanical properties
such as stiffness, toughness, and low creep that make them valuable in the
manufacture of structural products like gears, bearings, electronic devices,
and auto parts.
Teaching
Methodology:
PPT - UNIT IV
Learning
Resource (page
number)
R4- (70-72)
Lesson Title PROPERTIES AND APPLICATIONS OF PE,PP,PS,PVC
Lesson concept/
Points/Definitions
Plastics are also called synthetic resins and are broadly classified into two
categories: thermosetting resins and thermoplastic resins.
The thermosetting resins include phenolic resin and melamine resin, which
are thermally hardened and never become soft again. Thermoplastic resins
include PVC, polyethylene (PE), polystyrene (PS) and polypropylene (PP),
which can be re-softened by heating.
Teaching
Methodology:
PPT - UNIT IV
Learning
Resource (page
number)
T2- (158,159)
Lesson Title
Lesson concept/
Points/Definitions
Teaching
Methodology:
PPT - UNIT IV
Learning
Resource (page
number)
R4- (29,30)
Lesson Title PROPERTIES AND APPLICATIONS OF PMMA,PET,PC,PA,ABS

Lesson concept/
Points/Definitions
Extruded acrylic sheets are produced with extrusion technique. PMMA
comes out with changing of Monomer acrylic structure. PMMA is shaped as
sheet at extrusion lines. As long as machine allows, PMMA sheet is
produced as requested but there are a handful world standard sizes. It is
much lighter than glass. Also it is easy to handle and stack. Transparent
acrylic has % 92 light transmissions comparing to glass. PMMA has less
tolerance than cast acrylic sheet. Manufacturing process is obviously fast
• Perfect transparency
• High light transmission
• Good resistance to weather conditions
• High resistance to chemicals
• Wide temperature process range
• Protective film at both side
• Good impact strength
• Easy to process
• UV stability
Application
• Display systems
• Separators
• Bank equipment
• Vending machine
• Leaflet dispenser & card holder
• Indoor decoration
• Furniture
• Building materials
• Health sector
• Sales counter
Polyethylene terephthalate,(PET) thermoplastic polyester is a material
belonging to the family. Beverage, food and beverage containers, there are
application areas such as synthetic fiber. Heat processing, depending on
amorphous (transparent) and semi-crystalline (opaque and white) material is
available as Polethylene terephthalate construction
Most useful advantage is that it is completely recycle material. Unlike other
plastics, polymer chains, take the next use will lie in the former case.
Very high resistance to chemicals
• Excellent transparency
• Easy to fabricate
• Compatible with foodstuffs (not UV ver.)
• Excellent impact strength
• Good thermoforming properties
• Recycling
• Light weight compared to glass
Applications:
Health stuffs
• Separators
• Furniture
• Advertisement products
• Vacuuming
• Electronic devices
• Building materials
• Vending machines

• Packing
• Indoor & outdoor signs
Polycarbonate
It is an extruded high quality transparent polycarbonate sheet. It has a
superior impact strength at half the weight of glass. It has more than two
times impact strength of PET G and more than 10 times impact strength
of high impact PMMA. The product has an outstanding high clarity and
is more regularly replacing glass in exposed applications
In case of fire, it will melt and create a passage where heat and smoke
will be let out of the building. It will have no contribution to the growth
of a fire through flame spread
Outstanding high clarity
• Superior impact strength
• Good fire behavior classification
• Easily screen printed
• Can easily be formed into gentle curves
• Excellent thermoforming properties
• Usable over a wide temperature range
Applications:
• Security equipments
• Electronic equipments
• Medical materials
Acrylonitrile butadiene styrene or ABS with abbreviated names, products
manufactured via molding widely used in the polymer is a lightweight and
rigid. It is a thermoplastic sheet.
Easy to fabricate
• Resistance to chemicals
• Recycling
• Impact strength
Applications
• Automotive
• Toys
• Indoor and outdoor signs
• Vacuuming
• Health stuffs
• Vending machines
• Sales stands
• Furniture

• Electronic devices
Teaching
Methodology:
PPT - UNIT V-ISOPARAMETRIC FORMULATION
Learning
Resource (page
number)
R4- (44 to 51)
Lesson Title PROPERTIES AND APPLICATIONS OF PI, PAI, PPO,PPS, PEEK,PTFE
POLYMERS
Lesson concept/
Points/Definitions
Polycarbonate
It is an extruded high quality transparent polycarbonate sheet. It has a
superior impact strength at half the weight of glass. It has more than two
times impact strength of PET G and more than 10 times impact strength
of high impact PMMA. The product has an outstanding high clarity and
is more regularly replacing glass in exposed applications
In case of fire, it will melt and create a passage where heat and smoke
will be let out of the building. It will have no contribution to the growth
of a fire through flame spread
Outstanding high clarity
• Superior impact strength
• Good fire behavior classification
• Easily screen printed
• Can easily be formed into gentle curves
• Excellent thermoforming properties
• Usable over a wide temperature range
Applications:
• Security equipments
• Electronic equipments
• Medical materials
Acrylonitrile butadiene styrene or ABS with abbreviated names, products
manufactured via molding widely used in the polymer is a lightweight and
rigid. It is a thermoplastic sheet.
Easy to fabricate
• Resistance to chemicals
• Recycling
• Impact strength
Applications
•Automotive
•Toys

EMM COURSE FILE UPDATED.docx

Recommended

Recommended

More Related Content

Similar to EMM COURSE FILE UPDATED.docx

Similar to EMM COURSE FILE UPDATED.docx (20)

Recently uploaded

Recently uploaded (20)

EMM COURSE FILE UPDATED.docx