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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
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