ENGR 1210: FA 2016; HW 8 1 Homework 8 on chapters 8, 9 & 11; (Total points: 100) Reading assignments: Chapters 8, 9 & 11 from textbook and slides Student Name: _______________________________ MTSU ID: ____________________ Honor pledge: I _______________________________ acknowledge that I have neither received nor given any unauthorized help/aid during this assignment. Part 1 Key Engineering Terms: fill in the blanks – 30 points 1. Phase: a _____________________________________ homogeneous and distinct portion of material system. 2. Degrees of freedom: number of variables that can be changed ___________________________________________ without changing phases of the system. 3. Eutectoid: a steel with ____________________________ percent C. 4. Austenite has ____________________________________ crystal structure and maximum carbon solubility of 2%. 5. Martensite: a ______________________________________ interstitial solid solution of carbon in __________________________________________ iron. 6. Tempering: the process of _____________________________________________ a quenched steel to increase its toughness and ductility. 7. Spherodite: a mixture of particles of _________________________ in α iron matrix. 8. Hardenability: the ease of forming _________________________________________ in a steel upon quenching from austenitic condition. 9. White cast irons: contains large amounts of _____________________________________ which make them hard and brittle. 2 10. Gray cast iron: contain large amount of _______________________________ flakes. 11. Ductile cast iron: contain large amount of carbon in form of ___________________________________________. 12. Malleable cast iron: __________________________________ is added to composition other than iron and carbon. 13. Intermetallics: ___________________________________ compounds of metallic elements with high hardness and high temperature strength but brittle. 14. Shape memory alloys: metal alloys that recover previously defined shape when subjected to an appropriate _______________________________________. 15. Amorphous metal: metals with a ___________________________________ structure also called glassy metal. 16. Octahedral interstitial site: has coordination umber of ____________________________. 17. Tetrahedral site: has coordination number of _______________________________. 18. Ceramic materials: __________________________________ nonmetallic materials that consist of metallic and nonmetallic elements bonded together by ionic or covalent bonds. 19. Buckyball: is a soccer shaped molecule of _____________________________________ carbon atoms. 20. Firing: heating a ceramic material to high temperature to cause ______________________________________________ to form between particles. 21. Dry pressing: ______________________________________ uniaxial compaction and shaping of ceramic granular particles in a ...

1. ENGR 1210: FA 2016; HW 8
1
Homework 8 on chapters 8, 9 & 11; (Total points: 100)
Reading assignments: Chapters 8, 9 & 11 from textbook and
slides
Student Name: _______________________________ MTSU ID:
____________________
Honor pledge: I _______________________________
acknowledge that I have neither received
nor given any unauthorized help/aid during this assignment.
Part 1 Key Engineering Terms: fill in the blanks – 30 points
1. Phase: a _____________________________________
homogeneous and distinct portion
of material system.
2. Degrees of freedom: number of variables that can be changed
___________________________________________ without
changing phases of the
system.

2. 3. Eutectoid: a steel with ____________________________
percent C.
4. Austenite has ____________________________________
crystal structure and
maximum carbon solubility of 2%.
5. Martensite: a ______________________________________
interstitial solid solution of
carbon in __________________________________________
iron.
6. Tempering: the process of
_____________________________________________ a
quenched steel to increase its toughness and ductility.
7. Spherodite: a mixture of particles of
_________________________ in α iron matrix.
8. Hardenability: the ease of forming
_________________________________________ in
a steel upon quenching from austenitic condition.
9. White cast irons: contains large amounts of
_____________________________________ which make them
hard and brittle.
2

3. 10. Gray cast iron: contain large amount of
_______________________________ flakes.
11. Ductile cast iron: contain large amount of carbon in form of
___________________________________________.
12. Malleable cast iron:
__________________________________ is added to
composition
other than iron and carbon.
13. Intermetallics: ___________________________________
compounds of metallic
elements with high hardness and high temperature strength but
brittle.
14. Shape memory alloys: metal alloys that recover previously
defined shape when subjected
to an appropriate
_______________________________________.
15. Amorphous metal: metals with a
___________________________________ structure
also called glassy metal.
16. Octahedral interstitial site: has coordination umber of
____________________________.
17. Tetrahedral site: has coordination number of
_______________________________.

4. 18. Ceramic materials:
__________________________________ nonmetallic materials
that
consist of metallic and nonmetallic elements bonded together by
ionic or covalent bonds.
19. Buckyball: is a soccer shaped molecule of
_____________________________________
carbon atoms.
20. Firing: heating a ceramic material to high temperature to
cause
______________________________________________ to form
between particles.
21. Dry pressing: ______________________________________
uniaxial compaction and
shaping of ceramic granular particles in a die.
22. Isostatic pressing: the simultaneous compaction and shaping
of a ceramic powder by
pressure applied ____________________________________ in
all directions.
3
23. Sintering: the process in which fine particles of ceramic

5. material become chemically
bonded together at high temperature for
_______________________________________
to occur between particles.
24. Vitrification: melting or formation of
_______________________________________.
25. Refractory material: that can withstand the action of
___________________________________ environment.
26. Glass: a ceramic material made of
_______________________________________
materials.
27. Glass transition temperature: a center of temperature range
in which a
________________________________________________ solid
changes from being
glass brittle to being
_________________________________________.
28. Porcelain enamel: a glass coating applied to
_____________________________________ substrate.
Part 2 (Learning concepts/reflections/problems) – 50 points
1. List the 2 material properties and 2 relevant application for
following alloying elements

6. in aluminum:
a. Copper
b. Silicon
c. Magnesium
d. Silicon + Copper
2. (a) Describe the 5 steps in the slip-casting process for
ceramic products.
(b) What is tempered glass? How is it produced? Why is
tempered glass considerably
stronger in tension than annealed glass? What are some
applications for tempered glass?
4
3. Identify the following phase diagram. Identify the 3 stages of
age/precipitation hardening
as shown in the figure below and explain the various phases and
their
features/properties/microstructure at these stages.
4. For the following types of ceramic materials explain material
properties and one relevant

7. application for each.
a. alumina
b. diamond
c. silica
d. silicon carbide
e. boron nitride
5. (a) Sketch the microstructure of pearlite, bainite and
spherodite and explain key features.
5
Part 3 Materials Design Problems – 20 points
1. (a) Discuss the advantages and disadvantages of using
advanced ceramics in the structure of
internal combustion engines.
(b) Propose some methods of overcoming the shortcomings of
ceramics for this application.
2. Identify 2 properties and 2 relevant applications of following
materials:

8. (1) Brass (2) Bronze
Bonus – 10 points
1. What are glass intermediate oxides? How do they affect the
silica-glass network? Why
are they added to silica glass?
2. Explain, from an atomic structure point of view, why metals
can be plastically deformed
to form large and complex shapes while complex ceramic parts
cannot be manufactured
by this technique.
Note: Please use extra sheets wherever necessary to answer the
questions. All HW must be
uploaded via D2L Dropbox system. Students are highly
encouraged to refer textbook, notes
and slides.
Homework 8
Part 1
1. Physically
2. Independently
3. 0.8
4. FCC
5. Supersaturated - body center tetragonal
6. Reheating
7. Cementite
8. Martensitic
9. iron carbide
10. carbon in the farm of graphite

9. 11. carbon in the farm of graphite nodules
12. silicon
13. stoichiometric
14. heat- treatment procedure
15. non crystalline
16. 6
17. 4
18. inorganic
19. C60
20. a chemical bond
21. the simultaneous
22. uniformly
23. atomic diffusion
24. a glass
25. a hot
26. inorganic
27. non crystalline - viscous
28. a metal
Part 2
1.
Alloying element
Material properties
Applications
Silicon
• Good castability and high fluidity due to Al-Si eutectic
• High corrosion resistance
• Good weldability.
• Low solidification shrinkage.
• Machining difficulty in hypereutectic.
• Manufacturing of castings
• Filler wires for fusion welding • Brazing of aluminum
Silicon + Copper
• Cu addition increases strength and machinability
• Automotive cylinder heads/blocks in place of cast iron.
• Sand and permanent mould casting
Copper

10. • Strength and hardness at T up to 250oC is achieved from a
combination of precipitation hardening together with dispersion
hardening by intermetallic compounds.
• Strength is higher than other cast Al alloys and comparable to
wrought Al alloys.
• Aerospace housing
• Flywheel housing
Magnesium
• High resistance to corrosion
• Good machinability
• Attractive anodized surface.
• Little or no response to heat treatment.
• Chemical and sewage
• Kitchen utensils
2. A
• Powdered ceramic material and a liquid mixed to prepare a
stable suspension (slip).
• Slip is poured into porous mold and liquid portion is partially
absorbed by mold.
• Layer of semi-hard material is formed against mold surface.
• Excess slip is poured out of cavity or cast as solid.
• The material in mold is allowed to dry and then fired.
3.
·
Solution
treating – alloy is first heated above the solvus temperature at
548 C and held until a homogeneous solid solution α is
produced
· Quench – the alloy, which contains only in its structure, is

11. rapidly cooled, or quenched. After the quench, the structure is a
supersaturated solid solution αss. Diffusion less transformation.
· Age – the supersaturated α is heated at a temperature below
the solvus temperature. At this aging temperature, atoms diffuse
only short distances. α + θ phase formed
4.
· Alumina (Al2O3) is used to contain molten metal or in
applications where a material must operate at high temperatures
with high strength. Alumina is also used as a low dielectric
constant substrate for electronic packaging that houses silicon
chips. One classic application is insulators in spark plugs. Some
unique applications are being found in dental and medical use.
Chromium-doped alumina is used for making lasers. Fine
particles of alumina are also used as catalyst supports.
· Diamond (C) is the hardest naturally occurring material.
Industrial diamonds are used as abrasives for grinding and
polishing. Diamond and diamond-like coatings prepared using
chemical vapor deposition processes are used to make abrasion
resistant coatings for many different applications (e.g., cutting
tools). It is, of course, also used in jewelry.
· Silica (SiO2) is probably the most widely used ceramic
material. Silica is an essential ingredient in glasses and many
glass-ceramics. Silica-based materials are used in thermal
insulation, refractories, abrasives, as fiber-reinforced

12. composites, and laboratory glassware. In the form of long
continuous fibers, silica is used to make optical fibers for
communications. Powders made using fine particles of silica are
used in tires, paints, and many other applications.
· Silicon carbide (SiC) provides outstanding oxidation
resistance at temperatures even above the melting point of steel.
SiC often is used as a coating for metals, carbon-carbon
composites, and other ceramics to provide protection at these
extreme temperatures. SiC is also used as an abrasive in
grinding wheels and as particulate and fibrous reinforcement in
both metal matrix and ceramic matrix composites. It is also used
to make heating elements for furnaces. SiC is a semiconductor
and is a very good candidate for high-temperature electronics.
Part 3
Alloying element
Material properties
Applications
Bronze
• Bronzes are generally about 10 percent heavier than steel
• Bronzes are softer and weaker than steel
1. door and window frames
2. mail boxes and chutes
Brass
1-Highly malleable Acoustic properties
2- Corrosion resistance

13. 3-Moderate-high mechanical
4-strength Substitutional solid 5-solution of copper and zinc
1- decoration for its bright gold-like appearance
2- for applications where low friction is required such as locks,
gears, bearings, doorknobs, ammunition, and valves