Give the advantages and disadvantages of powder metallurgy compared to casting processes?

Answer 1

Advantage:

- High melting point metals can be fabricated below their melting points

- Special Structural Effects (Controlled porosity, Lamellar structure, Composite Structure, Controlled density)

- Flexibilities for producing PM parts with specific physical and mechanical properties like hardness, strength, density and porosity.

- Produces near net shape components. The technique required few or no secondary operations.

- The tolerance of components produced by this technique have quite high tolerance, therefore no further machining is not required.

- High Production Rate of small parts

- Parts can be produced with infiltration and impregnation of other materials to obtain special characteristics which are needed for specific application.

- No material is wasted as scrap during process.

Disadvantage:

- Cost for production of powder for Metallurgy is very high.(Only justified if >100,000 Parts)

- The tooling and equipments are very expensive, therefore becomes main issue with low production volume.

- Limited shapes and features. Powders cannot flow round corners.

- Complex shapes requires several punches, otherwise density will not be uniform.

- Difficult to produce large and complex shaped parts with powder metallurgy.

- Low ductility and strength. (Brittle)

- Difficult to handle low melting point metals as they tend to melt when sintered

- Slight shrinkage on sintering and cooling to room temperature

- Cannot be bent or cold worked due to brittleness

- Threaded feature can only be produced during secondary operations

- 1mm <Thickness< 2.5D