This document discusses powder metallurgy, which involves compacting metal powders and sintering them to produce dense materials. Powder metallurgy allows for precise control over material properties, custom alloy compositions, and production of near-net shaped parts. The key steps are powder production, blending and mixing powders, compacting the powders into a green compact, sintering the compact to bond particles, and optional finishing operations. Powder metallurgy is well-suited for producing alloys and materials that are difficult to make by other methods. Example applications include cutting tools, high speed steels, and wear-resistant components.

1. POWDER METALLURGY
B Y OME R WATHIQ ALANI

2. OBJECTS
• Introduction
• Why Pm?
• Advantages of pm
• Materials for Pm
• Operations of Pm
Powder production
 Blending and mixing of powders
Compaction
 Sintering
 Finishing operations
• Application

3. INTRODUCTION
• A fabrication technique involves the compaction of
powdered metal, followed by a heat treatment to
produce a more dense piece.
• Powder metallurgy is especially suitable for metals
having low ductility's
having high melting temperatures

4. WHY PM?
• The capability to produce parts to near net shapes
• Properties of components can vary in a wide range
(e.g.. porosity, electric conductivity, strength,
…etc.)
• The economics of the overall operation
• Alloys with special properties

5. ADVANTAGES OF PM
• PRECISE CONTROL : properties of end products can
be suited to the demands of applications
• CUSTOM-MADE COMPOSITION : widely different
characteristics can be compacted
• PHYSICAL PROPERTIES : properties can be altered
easily by this method(e.g. density, porosity)
• NEAR NETT SHAPING BECOMES NETT SHAPING
eliminating the further processes (e.g. machining)

6. MATERIALS FOR PM
• Metal powders (Fe, Cu, Ni, Ti, Co, W, Mo, …stb.)
• Alloys (HSS, bronze, stainless steels, …etc.)
• Non-metallic powders (graphite, metal carbides,
oxides, …etc.)

7. OPERATIONS OF PM
1. Powder production(metals, alloys, metalloids)
2. Blending and mixing of powders
3. Compaction
4. Sintering
5. Finishing operations

8. POWDER PRODUCTION

9. POWDER PRODUCTION

10. SHAPE AND SIZE OF POWDERS
• Shape and size of powders depend on the method
of production
• Particle size range: 0,001…1 mm
• Shapes (one-, two, three dimensional):
spherical
elongated
 irregular
porous

11. BLENDING AND MIXING OF
POWDERS
• For successful results in compaction and sintering,
the starting powders must be homogenized
• Blending - powders of the same chemistry but
possibly different particle sizes are intermingled
• Mixing - powders of different chemistries are
combined
• PM technology allows mixing various metals into
alloys that would be difficult or impossible to
produce by other means

12. BLENDING AND MIXING OF POWDERS
Blending and mixing are accomplished by
mechanical means:

13. COMPACTION
• Application of high pressure to the powders to form
them into the required shape
• The conventional compaction method is pressing, in
which opposing punches squeeze the powders
contained in a die
• The work part after pressing is called a green
compact, the word green meaning not yet fully
processed
• The green strength of the part when pressed is
adequate for handling but far less than after
sintering

14. COMPACTION

15. COMPACTION

16. COMPACTION
• There are different ways to improve the density
distribution:

17. SINTERING
• Compressed metal powder is heated in a controlled-atmosphere
furnace to a temperature below its melting point( between 70% to
90% of melting point) , but high enough to allow bounding of the
particles

18. SINTERING
• The primary driving force for sintering is not the
fusion of material, but formation and growth of
bonds between the particles

19. FINISHING OPERATIONS
• Coining and sizing: improve dimensional accuracy,
strength and surface finish
• Cold forging, upsetting: modify shape, increase
strength
• Impregnating with fluid: bearings and bushes
• Infiltration: molten metal infiltrates the pores

20. APPLICATION
High Speed Steels
Process:
•Welding
•Hot isostatic compaction
•Rolling
•Forging
Product: Bars, forged
parts

21. APPLICATION
cutting tools
W- and Ti-carbide
plates for highspeed
cutting

22. APPLICATION

23. APPLICATION

25. Thank you!