Powder Metallurgy Topics covered : Introduction, Manufacturing, Blending, Compaction, Sintering.

1. Government Engineering
College
Rajkot

2. NAME : PARAS SAVALIYA
ENROLLMENT NO. : 150200119056
SUBJECT : MATERIAL SCIENCE AND
METALLURGY
DEPARTMENT OF MECHANICAL
ENGINEERING

3. POWDER METRALLURGY
Introduction
Powder Manufacture
Blending
Compacting
Sintering
Finishing Operations
Products

4. Introduction
 Powder Metallurgy is manufacturing of shaped
components or semi finished products from metal
powders.
 Powder Metallurgy is preferred due to it’s product cost
effectiveness. The main factors are:
1. Lower energy consumption.
2. Higher material utilization.
3. Production of complex shapes.
 Product uniqueness can be obtained by combination
of materials which otherwise would be impossible to
mix.

5. Powder Metallurgy Process

6. Powder Manufacture
 The first step of powder metallurgy is powder
manufacturing
 It involves making, characterizing, and
treating the powder which may have a strong
influence on the quality of the end product.

7. Techniques of Powder Making
 Atomizing Process
 Gaseous Reduction
 Electrolysis Process
 Carbonyl Process
 Stamp and Ball Mills
 Granulation Process
 Mechanical Alloying

8. Atomization
 In this process the molten metal is forced through an
orifice into a stream of high velocity air, steam or inert
gas.
 This causes rapid cooling and disintegration into very
fine powder particles.
 The use of the process is limited to metals with
relatively low melting point.
 There are three types of Atomization
Liquid Atomization
Gas Atomization
Centrifugal Atomization

9. Melt Atomization

11. Powder Blending
 Powder blending is done due to following reasons:
Blending imparts uniformity in shapes of the powder
particles.
Facilitates mixing of different powder particles to
improve physical and mechanical properties.
Lubricants can be added to during blending to
improve the flow and reduce friction between powder
and dies.
Binders can be added to improve the green strength of
material during compaction process.

12. Powder Blending Machines

13. Powder Compaction
 It is the process of compacting metal powder in a die
through the application of high pressures.
 The compaction exercise imparts the following:
 Reduces voids between the powder particles and
enhances density.
 Produces adhesion and bonding between the
powder particles to improve green strength

14. Compaction of metal powder to form
bushing

16. Sintering
 The sintering process consists of heating the
compacted green mold in a furnace to a temperature
below the highest melting point from the
constituents.
 Sintering is applied to achieve all possible final
strength & hardness required for the finished
product.
 The time, temperature and furnace atmosphere
are the three critical factors that control the sintering
process.

18. Finishing Operations
 After sintering, some finishing operations such as
repressing(to impart dimensional accuracy) and
machining are carried out to further improve final
quality of parts.
 Parts are also subjected to other finishing
operations such as heat treatment, machining and
finishing according to the requirements.

19. Products
•Bearings
•Gears
•Milling Cutters
•Pressure
Regulators
•Flow Regulators

20. References:
NPTEL Booklet
Google Images