POWDER METALLURGY

Prof. J Viplava Kumar MME,MGIT

Manufacturing Techniques

Conventional route

Foundry/ Casting

Powder Metallurgy

Outline Introduction Production of Powders Consolidation Applications

Advantages Economical mass production technology Scrapfree technology Unique technique: Porous Components, Cermets, Refractory Metals, Cemented carbides

Limitations Limitations on shape and size of products Health hazards Fine powders of reactive metals - pyrophoric

Applications

• Tungsten filaments:

Production of Powders

Atomization Example: Powders of Superalloys, HSS, Cu-Al

ii) Reduction of oxides Fe powder at Hoganas

iii) Chemical reduction: Carbonyl Ni and Fe

iv) Chemical + Mechanical methods: Stainless steel, Ti, Zr (NFC-ECIL)

Consolidation Techniques

i. Compactionii. Sintering

Compaction: Shaping, deformation and densification of a powder

by application of Pressure

Die Compaction:

Schematic of the die compaction process

Compaction

Die- compaction

Isostatic compaction

Isostatic Compaction

Applying stress uniformly in all directions

Isostatic Compaction

Cold Isostatic Compaction

Hot Isostatic Compaction

Schematics of Isostatic Pressing

Cold Isostatic Compaction:

Hot Isostatic Pressing:

Sintering: Thermal process which increases the strength of a

powder mass by bonding adjacent particles via diffusion

Steps of Sintering

Liquid phase sintering:

WC- Co system

Thank You