This document provides an introduction to powder metallurgy, including the powder metallurgy process, production of metallic powders, blending and mixing powders, compacting powders, sintering compacts, and applications of powder metallurgy. Powder metallurgy involves forming metal parts by heating and compacting metal powders below the melting point, allowing for net-shape production of parts. Key steps include powder production, blending, compacting in a die, and sintering to bond particles. Powder metallurgy is used to make automotive, aerospace, medical, and other precision components when high production rates and material efficiency are priorities.

1. INTRODUCTION TO
POWDER
METALLURGY
KEVIN PEREIRA

2. POWDER METALLURGY
• Powder metallurgy is a process for forming metal parts
by heating compacted metal powders .
• It is a superior way of producing high-quality parts for a
variety of important applications.
• The working temperature is well below the melting point
of the major constituent, making it a very suitable
method to work with refractory materials, such as: W,
Mo, Ta, Nb, oxides, carbides, etc.

3. POWDER METALLURGY
PROCESS
 Powder production
 Blending or mixing
 Powder compaction
 Sintering
 Finishing Operations

4. POWDER METALLURGY PROCESS

5. PRODUCTION OF
METALLIC POWDERS
Any metal can be made into powder form
Three principal methods by which metallic powders are
commercially produced
 Atomization (by gas, water, also centrifugal one)
 Chemical decomposition or oxidation.
 Electrolysis. (copper)
In addition, mechanical methods are occasionally used to
reduce powder sizes

6. BLENDING OR MIXING
Blending a coarser fraction with a finer fraction ensures that
the pores will be filled out.
Powders of different metals and other materials may be
mixed in order to impart special physical and mechanical
properties through metallic alloying.
Lubricants may be mixed to improve the powder’s flow
characteristics.
Binders such as wax or thermoplastic polymers are added to
improve green strength.

7. Press powder into the desired shape and size in dies using a
hydraulic or mechanical press
• Pressed powder is known as “green compact” The green strength
of the part when pressed is adequate for handling.
COMPACTING

8. SINTERING
• Heat treatment to bond the metallic particles,
thereby increasing strength and hardness.
• Parts are heated to ~80% of melting temperature.

9. POWDER METALLURGY
MERITS
 Near Nett Shape is possible, thereby reducing the post-
production costs, therefore:
 Precision parts can be produced
 The production can be fully automated, therefore,Mass
production is possible
 Production rate is high
 Material loss is small

10. ADVANTAGES OF P/M
Virtually unlimited choice of alloys, composites, and
associated properties .
Refractory materials are popular by this process
Can be very economical at large run sizes (100,000 parts)
Long term reliability through close control of dimensions
and physical properties
Different variety of shape and size.
Very good material utilization

11. LIMITATIONS
• High tooling and equipment costs.
• Metallic powders are expensive.
• Limitations on part geometry because metal
powders do not readily flow laterally in the die
during pressing.
• Variations in density throughout part may be a
problem, especially for complex geometries.

12. POWDER METALLURGY
DISADVANTAGES
 Porous !! Not always desired.
 Large components cannot be produced on a
large scale.
 Some shapes are difficult to be produced by
the conventional p/m route.

13. APPLICATION OF P/M

14. Connecting Rods:
Forged on left; P/M on
right
Powdered Metal Transmission Gear
AUTOMOTIVE
COMPONENTS

15. AEROSPACE COMPONENTS
High temperature composite materials.
Light weight alloys.

16. MEDICAL APPLICATIONS
Surgical
instruments
Dental implants

17. OTHER
APPLICATIONS
CUTTING TOOLS
ABRASIVES
• Grinding discs
• polishing wheels and discs.
ELECTRONIC COMPONENTS
• Computer parts,
• electrical contacts for handling large current flows;
• magnets etc.

18. OTHER COMPONENTS

19. THANK
YOU