Material selection for manufacturing

1. MATERIAL SELECTION FOR
MANUFACTURING
Presented by:
Anit Jain
Lalit Soni,
VIT University

2. MATERIAL SELECTION
Material selection is a step in the process of designing any
physical object. In the context of product design, the main goal
of material selection is to minimize cost while meeting product
performance goals.
The designer of any product, other than software must get
involved with material selection.
Appropriate selection of material is significant for the safe and
reliable functioning of a part or component.

3. Decisions, decisions!
So many materials, so much information.
How do we decide?
How do we begin to choose?

4. MATERIAL SELECTION CHART
o Materials selection chart are used for 2 common properties:
1. Young's modulus (which describes how stiff a material is)
2. Density.
o On these charts, materials of each class (e.g. metals,
polymers) form 'clusters' or 'bubbles' that are marked by the
shaded regions

5. MATERIAL SELECTION CHART

6. o From the material selection chart we can see immediately
that:
 metals are the heaviest materials,
 foams are the lightest materials,
 ceramics are the stiffest materials.
o Selection charts are really useful is in showing the trade-
off between 2 properties, because the charts plot
combinations of properties.
o Like if we want a light and stiff material we need to choose
materials near the top left corner of the chart - so composites
look good.
o There are a selection charts for many combinations of
material properties, e.g. 'strength - toughness' and 'electrical
resistivity - cost

7. STRATEGY FOR MATERIALS
SELECTION
There are mainly 4 steps:
1. Translation: Examining the design requirements to identify
the constraints that they impose on material choice.
2. Screening-out: The immensely wide choice is narrowed
first, by the materials that cannot meet the constraints.
3. Ranking: Further narrowing is achieved by ranking the
candidates as per their ability to maximize performance
4. Seek supporting information

9. Translation
The problem of selection of an engineering material for a
component usually begins with setting up the 4 below
things for target
• Function: It refers to the task that the component is
primarily expected to perform in service – for example,
support load, sustain pressure, transmit heat, etc.
• Constraints: That certain dimensions are fixed, that the
component must carry the design loads or pressures
without failure, that it insulates or conducts, that it can
function in a certain range of temperature and in a given
environment, and many more.

10. Objective: Refers to the target such as making the component
functionally superior but cheap and light. In other words,
the Objective refers to what needs to be minimized or
maximized.
Free variables: Certain parameters can be adjusted in order to
optimize the objective—the designer is free to vary
dimensions that have not been constrained by design
requirements.

11. Material Index (M)
The Material Index (M) refers to an attribute (or a combination
of attributes) that characterizes the performance of a material
for a given application.
The material index allows ranking of a set of engineering
materials in order of performance for a given application.

12. Material Indices can be better explained
by following example
Selection of Material for a Light and Strong Tie-Rod
Now, as per the translation process

13. Material Index (M1) would provide a premise to examine if a material
with higher weight (density) has to be selected to ensure that the same
has sufficient strength to avoid failure.

14. Case Study – A Bike
What is the function of a bike – obvious?
How does the function depend on the type of bike?
• Racing
• Touring
• Mountain bike
• Commuter
• Childs

15. • How is it made to be easily maintained?
• What should it look like (colours etc.)?
• What should it cost?
• How has it been made comfortable to ride?
• How do the mechanical parts work and interact?

16. The bike breaks down into various parts:
• Frame
• Forks
• Wheels
• Saddle
• Etc.

17. We now need to look at the following for each part:
• Requirements (mechanical, ergonomic, aesthetic
etc.)
• Function
• How many are going to be made?
• What manufacturing methods are we going to use?

18. Frame Materials
• Steel –
Strong, stiff, heavy, but cheap
• Aluminium –
weaker, lighter, more expensive than steel
• Composite (CFRP) –
strong, stiff, very light, but expensive to buy and to
fabricate

19. Bike Frame

20. What Properties?
• Mechanical –
Strength, modulus etc.
• Physical –
Density, melting point.
• Electrical –
Conductivity, resistivity.
• Aesthetic –
Appearance, texture, colour
• Processability –
Ductility, mouldability
• And last, but not least……….
Cost, cost, cost!

21. Case Study (2) Drink Container
• What are the requirements?

22. • Provide leak free environment for storing liquid.
• Comply with food standards & protect liquid from
health hazards.
• For fizzy drinks, withstand pressure.
• Brand image & identity
• Easy to open
• Easy to store & transport
• Cheap for high volumes

23. Possible Materials
• Steel
• Aluminium
• Glass
• Plastic
• Paper

24. THANK YOU