Presintering
· Powder metallurgy is used to make parts from materials that are very difficult to machine.
· When some machining is required on such parts, Presintering is done before actual sintering operation.
· Compact is heated for a short time at a temperature below sintering temperature
· Presintering removes lubricants and binders added to powders during blending operation.
· After presintering, the part acquires sufficient strength to be handled and machined without difficulty
Sintering
· Sintering is the heat treatment process, to bond the metallic particles, thereby increasing strength and hardness
· Sintering consists of heating pressed metal compacts in batch or continuous furnaces to a temperature below the melting point of material.
· Most metals are sintered at 70 % to 80 % of melting temperature.
Sintering