MFE 201 Lecture Notes - Lecture 10: Powder Metallurgy, Sintering, Incandescent Light Bulb
31 Mar 2016
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Sintering steps: remove binders and lubricants through slow heat ramp up. The part is slowly heated to allow the binders and lubricants to evaporate and escape through the interconnected part porosity. If heated too fast, the internal pressure may burst the weak green preform: sinter (particle bonding) through high temperature. Here the powder particles fuse with each other. There is extensive dimensional contraction (10-20%) consolidation and this is where the mechanical properties develop. Homologous melting temperature: cool down in protective atmosphere. The part cools down in a protective environment to protect against oxidation throughout the porous part. Schematic illustration of two mechanisms for sintering metal powders: (a) solid-state material transport; (b) liquid-phase material transport. The main di erence is that the solid state sintering will result in signi cant dimensional shrinkage and consolidation. This is the sintering mechanism most common with powder metals. Complexity in x-y plane, at in z direction.
