1. Material - Process Selection
Polycarbonate?
Aluminum?
Stainless steel?
Die cast?
Forged?
Stamped?
Molded?
CRS?
Nylon 6?
Zinc?
Poli, C., Design for Manufacture: a structured approach, 2011, 1st Ed, Butterworth-Heinmann

2. Decisions Decisions Decisions
Proposed replacement part
Original 5-part assembly
Question: Should we replace the original 5-part assembly with a single part?
Question: If so -what material should the part be made of?
-what process should be used to make the part?
Question: Should we choose the material first?
Should we select the process first?

3. Materials First Approach
Consider application information such as stresses, environment, codes, disposal, etc.
Based on this information, select feasible material classes
Now select associated process types
Now consider application information such as stresses, environment, codes, disposal,etc.
Select feasible process and material

4. Process First Approach
Consider part information such as size, shape, production volume, etc
Based on this select feasible process types
Select associated materials classes
Now consider application information such as stresses, environment, codes, disposal,etc.
Select feasible process and material

5. Properties of Selected Cast Alloys

6. Properties of Selected Wrought Alloys

7. Properties of Selected Plastics

9. Concurrent Engineernig
Team
Product Design
Process Design
Production Control
Marketing
Production
Shipping
Involve Everyone (Team Approach)- from beginning to end / from cradle to grave
Product and process design done simultaneously rather than sequentially

10. Taxonomy of the kingdom of materials, process and their attributes

11. Preliminary Material-Process Selection Cast Metals

12. Preliminary Material-Process Selection Thermoplastics

13. Preliminary Process and Material Selection - Wrought Processes

14. Preliminary Process and Material Selection - Casting Processes

15. Preliminary Process and Material Selection - Plastic Processes

16. Level I: Metals vs Plastics
Can be formed into almost any shape with no finishing
Resist corrosion better
Better insulators
Plastics less dense
Less costly

17. Level I: Metals vs Plastics - continued
Metals have better mechanical properties
Better thermal and electrical conductivity; higher temp. capabilities
Can be processed by a fast process - stamping!

18. Level II - Cast vs Wrought
To choose must know:
- How easily can the material be shaped?
- Mechanical and physical properties.
Complex shapes
- Easy to cast
- Difficult to forge
Castings: - small voids - pockets of impurities (inclusions) - large grain structure - poorer mechanical properties
Forgings: - start with cast billet that was then rolled/drawn/extruded - squeeze between die halves - formed using 2-3 stages - better mechanical properties

19. Level II - Cast vs Wrought - continued
Mechanical properties (ductility and strength) are improved by wrought processes.
For alloys of the same composition - wrought better than cast
By choice of composition - high carbon steel casting better properties than low carbon steel sheet
Specify desired mechanical properties- producer adjusts composition.

20. Level II - Cast vs Wrought - continued
Consider casting process/alloy
- complex/hollow shapes
- large parts
- when several parts can be combined
Consider wrought alloys/processes
- simple geometry
- fast process such as stamping or extrusion can be used

21. Level II- Thermoplastic vs Thermoset
Thermoplastics faster and easier to process
Thermosets have higher flexural modulus => more rigid

22. Level III: Ferrous vs Non-ferrous
Ferrous more resistant to corrosion
Easier to fabricate due to lower tensile and yield strengths
Better thermal and electrical conductors
Lighter in weight
Non-ferrous better mechanical properties; stiffer

23. Level III: Steels Strength, hardness, wear resistance increases
As carbon content increases, ductility (%elongation) decreases
structural shapes, forgings,plates
hammers, dies, tool bits
Resist corrosion, high strength

24. Polycarbonate has highest impact resistance
Level III: Plastics
Nylon has low coefficient of friction => used for bearings, bushings, gears, etc
Polycarbonate has highest impact resistance
Plastics with fillers have improved mechanical properties, electrical and thermal conductivities and cost more

25. Injection molded: polycarbonate
Level IV
At the parametric stage of design we pick the specific alloy or resin
Die cast: aluminum A380.0
Injection molded: polycarbonate
Stamped: CRS ASTM A606

26. Example 1

27. Example 2