The document discusses material selection for a disc clutch component in a bicycle flywheel project. It describes using Ashby's material selection method and the CES EduPack software to rank material attributes and select materials based on charts plotting hardness vs specific heat, price vs specific heat, and machinability vs price. This led to selecting cast aluminum alloy as it met desired criteria of hardness, price, heat capacity and machinability. High carbon steel and aluminum/silicon carbide composite were identified as alternative materials.

1. Advance Material and Manufacturing Technologies
By
Shobin John
1/10/2017
halmstad university, masters in mechanical
engineering 2015.
shojoh15@student.hh.se
1
CASE1:Material Selection

2. MATERIAL WORLD
 The material world serves a
huge list of functions.
 The evolution was faster and
the range of properties more
varied.
 The birth of materials is
dated back to the birth of the
first invention , though it
existed even before
 New materials were invented
with time and its applications
varied
 From wheel to the ultra
modern Nano-technology
instruments – material is vital
 Ashby’s chart depicts the
material invention and its
usage over the years 1/10/2017
halmstad university, masters in mechanical
engineering 2015. shojoh15@student.hh.se2

3. • Classifying materials is vital for
the ease of identification in
practical applications
• Periodic table was one great
invention but not good enough
as it does not include the whole
list of engineering materials
• Ashby’s classification of
materials can overcome this
drawback and is as depicted in
the picture
1/10/2017
halmstad university, masters in mechanical
engineering 2015.
shojoh15@student.hh.se
3

4. SELECTION OF MATERIALS
• The task of material selection can be simplified by its ordered
classification into kingdom, family, class, subclass, member and attributes
(Ashby’s selection method)
• This can be used to arrive at a point specific from a diverse wide
• An example is as depicted in the diagram
1/10/2017
halmstad university, masters in mechanical
engineering 2015.
shojoh15@student.hh.se
4

5. SELECTION TECHNIQUE and its structure
• The myriad number of materials and its diverse properties, makes
material selection process peccable
• CES EduPack is a software to overcome this dilemma
• It helps to identify the apt material from the material classification
world. The structure of the software is as shown in the second figure
1/10/2017
halmstad university, masters in mechanical
engineering 2015.
shojoh15@student.hh.se
5

6. CES SOFTWARE AND TYPES OF CHARTS
• CES software makes the material selection process less tedious
• A huge list of material properties and its applications are included in its
database
• Chart is the main tool used in this software for screening the choices
• It can be done making use of either the bubble chart or the bar chart as
depicted
• Comparison of the selected materials can be made through the graph
based on the desired characteristics
1/10/2017
halmstad university, masters in mechanical
engineering 2015.
shojoh15@student.hh.se
6

7. MATERIAL SELECTION FOR PRODUCT DEVELOPMENT PROCESS
DISC CLUTCH
 Project involves flywheel installed
on bicycle and is named as
Flywheel on bicycle.
 System requires a component
clutch which is used to adjust the
gear and flywheel.
 The engagement and
disengagement for changing gear
and flywheel is the function of
clutch
 Importance was low to moderate
as identified in the QFD
1/10/2017
halmstad university, masters in mechanical
engineering 2015. shojoh15@student.hh.se7

8. IDENTIFYING ATTRIBUTES
 Primary feature being machinability and
possessing high hardness.
 Price factor has to be low due to the relatively low
importance shown from the QFD analysis
 Aesthetically high will add value
 Heat carrying capacity has to be moderately high
to overcome friction and heat generation.
 Chemical inertness and recyclability can help in
improving environmental aspects
1/10/2017
halmstad university, masters in mechanical
engineering 2015. shojoh15@student.hh.se8

9. RANKING ATTRIBUTES AND GRAPH SELECTION
SL NO ATTRIBUTES
1 MACHINABILITY
2 PRICE
3 SPECIFIC HEAT
CAPACITY
4 RECYCLABILITY
5 ELECTRICAL PROP
6 TENSILE STRENGTH
7 HARDNESS
RANK ATTRIBUTES
1 MACHINABILITY
2 SPECIFIC HEAT CAPACITY
3 PRICE
4 HARDNESS
5 RECYCLABILITY
6 TENSILE STRNGTH
7 ELECTRICAL PROP
 Attribute ranking shows that the material has to be identified on the
properties of hardness, specific heat capacity, machinability and price
 Following graphs are selected for material selection
• Hardness vs. Specific heat
• Price vs. Specific heat
• Machinability vs Price 1/10/2017
halmstad university, masters in mechanical
engineering 2015. shojoh15@student.hh.se9

10. Hardness vs. specific heat capacity
 this graph is used for the primary screening of material as identified from the attribute ranking
 the desired category is identified as the Hardness section
 the materials have higher specific heat and hardness of the graph is assumed to serve the purpose and
compared against the other graphs as identified
 Aluminum alloy, high carbon steel and aluminum/silicon carbide composite are chosen to start with
1/10/2017
halmstad university, masters in mechanical
engineering 2015. shojoh15@student.hh.se10

11. PRICE vs. SPECIFIC HEAT CAPACITY
 Trivial importance of the component realizes the vital importance of the
material cost
 The price range is chosen as shown as the desired category
 This eliminates ALUMINUM/SILICON CARBIDE COMPOSITE which
was chosen in the first graph as it costs around 5 USD/lb.
 ALUMINUM ALLOY and HIGH CARBON STEEL exist
Specific heat capacity (BTU/lb.°F)
0.05 0.1 0.2 0.5
Price(USD/lb)
0.01
0.1
1
10
100
1000
10000
Price vs Specific heat capacity
Cast iron, gray
High carbon steel
Cast Al-alloys
Aluminum/Silicon carbide composite
1/10/2017
halmstad university, masters in mechanical
engineering 2015. shojoh15@student.hh.se11

12. MACHINABILITY VS PRICE
 The final graph indicates CAST ALUMINUM ALLOY as the material to be
selected
 Though HIGH CARBON STEEL can be an alternative, the machinability
aspect indicates that it cannot be apt
 Further the recyclability, high melting point and service temperatures,
electrical insulation and chemical inertness shows that CAST ALUMINUM
ALLOY can be selected over HIGH CARBON STEEL and
ALUMINUM/SILICON CARBIDE COMPOSITE
Price (USD/lb)
0.1 1 10
Machinability
1
2
3
4
5
Machinability vs Process
Cast iron, gray
High carbon steel
Aluminum/Silicon carbide composite
Cast Al-alloys
1/10/2017
halmstad university, masters in mechanical
engineering 2015. shojoh15@student.hh.se12

13. Final selection and alternatives
MATERI
AL
HARDNE
SS
PRICE HEAT
CAPACIT
Y
MACHIN
ABILITY
RECYCLE CHEMIC
AL
RESISTA
NCE
ELECTRI
CAL
RESISTIV
ITY
CAST
ALUMIN
UM
ALLOY
60-
150HV
0.989-
1.09USD
/lb
0.215-
0.238BT
U/lb.°F
4.5 YES YES 2.5-
8µohm.c
m
HIGH
CARBON
STEEL
400HV 0.2USD/
LB
0.18BTU
/LB,F
3.5 YES YES 200MIC
ROOHM.
CM
ALUMIN
UM/SILI
CON
CARBIDE
COMPOS
ITE
70-
140HV
2.82-
3.76USD
/lb
0.191-
0.215BT
U/lb.°F
1.7 YES YES 5-
12µohm.
cm
1/10/2017
halmstad university, masters in mechanical
engineering 2015.
shojoh15@student.hh.se
13

14. CONCLUSION:
CAST ALUMINUM ALLOY WAS THE APT MATERIAL AS IT COVERED A WIDE RANGE OF DESIRED
CHARACTERISTICS.
Mechanical properties
Young's modulus 10.4 - 12.9 10^6 psi
Shear modulus 3.63 - 4.93 10^6 psi
Bulk modulus 9.57 - 10.4 10^6 psi
Poisson's ratio 0.32 - 0.36
Yield strength (elastic limit) 7.25 - 47.9 ksi
Tensile strength 9.43 - 56 ksi
Compressive strength 7.25 - 47.9 ksi
Elongation 0.4 - 10 % strain
Fatigue strength at 10^7 cycles 4.64 - 22.8 ksi
Mechanical loss coefficient (tan delta) 1e-4 -0.002
ALTERNATIVES:
Suggestion 1: HIGH CARBON STEEL
Reason: The table indicates HIGH CARBON STEEL to have a desired characteristics except
machinability. aspect in context of the product.
Suggestion 2: ALUMINUM/SILICON CARBIDE COMPOSITE
Reason: The table indicates ALUMINUM/SILICON CARBIDE COMPOSITE to possess the highest
electrical resistance and the moderate hardness. The price being on the higher end is a
concern but can still be used where reliable is valued over price.
1/10/2017
halmstad university, masters in mechanical
engineering 2015.
shojoh15@student.hh.se
14