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05/02/2023 halmstad university, masters in mechanical engineering 2015. [email protected]
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Advance Material and Manufacturing Technologies
ByShobin John
CASE1:Material Selection
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
05/02/2023halmstad university, masters in mechanical engineering 2015. [email protected]
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05/02/2023 halmstad university, masters in mechanical engineering 2015. [email protected]
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CLASSIFICATION OF MATERIAL WORLD
• 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
05/02/2023 halmstad university, masters in mechanical engineering 2015. [email protected]
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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
05/02/2023 halmstad university, masters in mechanical engineering 2015. [email protected]
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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
05/02/2023 halmstad university, masters in mechanical engineering 2015. [email protected]
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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
TransparencyOptical Quality
Max
imum
serv
ice
tem
pera
ture
(°C)
300
400
500
600
700
800
MATERIAL SELECTION FOR PRODUCT DEVELOPMENT PROCESS
DISC CLUTCHProject 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
05/02/2023halmstad university, masters in mechanical engineering 2015. [email protected]
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IDENTIFYING ATTRIBUTESPrimary 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 valueHeat carrying capacity has to be
moderately high to overcome friction and heat generation.
Chemical inertness and recyclability can help in improving environmental aspects
05/02/2023halmstad university, masters in mechanical engineering 2015. [email protected]
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RANKING ATTRIBUTES AND GRAPH SELECTION
SL NO ATTRIBUTES1 MACHINABILITY2 PRICE3 SPECIFIC HEAT
CAPACITY4 RECYCLABILITY5 ELECTRICAL PROP6 TENSILE STRENGTH7 HARDNESS
RANK ATTRIBUTES1 MACHINABILITY2 SPECIFIC HEAT CAPACITY3 PRICE4 HARDNESS5 RECYCLABILITY6 TENSILE STRNGTH7 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
05/02/2023halmstad university, masters in mechanical engineering 2015. [email protected]
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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
Hardness - Vickers (HV)0.001 0.01 0.1 1 10 100 1000
Spec
ific
heat
cap
acity
(BTU
/lb.
°F)
0.05
0.1
0.2
0.5
High carbon steel
Cast iron, gray
Aluminum/Silicon carbide composite
Cast Al-alloys
05/02/2023halmstad university, masters in mechanical engineering 2015. [email protected]
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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
Pric
e (U
SD/l
b)
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
05/02/2023halmstad university, masters in mechanical engineering 2015. [email protected]
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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
Mac
hina
bilit
y
1
2
3
4
5 Machinability vs ProcessCast iron, gray
High carbon steel
Aluminum/Silicon carbide composite
Cast Al-alloys
05/02/2023halmstad university, masters in mechanical engineering 2015. [email protected]
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05/02/2023 halmstad university, masters in mechanical engineering 2015. [email protected]
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Final selection and alternativesMATERIAL
HARDNESS
PRICE HEAT CAPACITY
MACHINABILITY
RECYCLE CHEMICAL RESISTANCE
ELECTRICAL RESISTIVITY
CAST ALUMINUM ALLOY
60-150HV
0.989-1.09USD/lb
0.215-0.238BTU/lb.°F
4.5 YES YES 2.5-8µohm.cm
HIGH CARBON STEEL
400HV 0.2USD/LB
0.18BTU/LB,F
3.5 YES YES 200MICROOHM.CM
ALUMINUM/SILICON CARBIDE COMPOSITE
70-140HV
2.82-3.76USD/lb
0.191-0.215BTU/lb.°F
1.7 YES YES 5-12µohm.cm
05/02/2023 halmstad university, masters in mechanical engineering 2015. [email protected]
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CONCLUSION: CAST ALUMINUM ALLOY WAS THE APT MATERIAL AS IT COVERED A WIDE RANGE OF DESIRED CHARACTERISTICS.Mechanical propertiesYoung's modulus 10.4 - 12.9 10^6 psiShear modulus 3.63 - 4.93 10^6 psiBulk modulus 9.57 - 10.4 10^6 psiPoisson's ratio 0.32 - 0.36Yield strength (elastic limit) 7.25 - 47.9 ksiTensile strength 9.43 - 56 ksiCompressive strength 7.25 - 47.9 ksiElongation 0.4 - 10 % strainFatigue strength at 10^7 cycles 4.64 - 22.8 ksiMechanical loss coefficient (tan delta) 1e-4 -0.002 ALTERNATIVES:Suggestion 1: HIGH CARBON STEELReason: 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.
