·         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