Powder Metallurgy

1
Powder Metallurgy

• By Jenna Justice

2
History of Applications

• 3000 B.C. Egyptians made tools with powder
  metallurgy
• 1900s tungsten filament for light bulb
• 1930s carbide tool materials
• 1960s automobile parts
• 1980s aircraft engine turbine parts

3
Advantages

• Ability to create complex shapes
• High strength properties
• Low material waste
• Good microstructure control

4
Disadvantages

• Creation of residual pores
• High tooling costs

5
Sintering Process

• Uses a sintering atmosphere and a sintering
  furnace
• The atmosphere transfers heat to the compacted
  powder, adjusts impurity levels and remove
  lubricants.
• Atmosphere can be pure hydrogen, nitrogen or
  ammonia.

6
Sintering Process Cont.

• Furnace provides time and temp. control.

Continuous Furnace
7
Sintering on Particles

• The particles will stretch and densification will
  form in places of rapid shrinking.

8
Hot Isostatic Pressing

• Produces powder metal parts to near full density
  and shapes of varying complexity.
• Performed in a pressurized fluid.
• Uses lower pressures to densify a powder by
  atomic movement.

9
Hot Isostatic Pressure System
10
Steel formed from HIP
11
Design Considerations

• Use on parts with 1000 callouts or less on
  engineering drawings.
• Production rate of a few thousand per year.
• Mass range from 1 to 1000 grams

12
Conclusions

• Powder metallurgy would be ideal for UAVs in the
  defense world because of the ability to
  manufacture parts that are smooth with complex
  curves and shapes and still retain relatively
  high strength. More applications will use powder
  metallurgy in the future as the process improves
  and the parts retain full density.