Warm compaction of titanium and titanium alloy powders

Abstract Titanium and titanium alloy powder compacts with high relative density of more than 90% can be produced by warm compaction at die temperatures ranging from room temperature to 550°C. The use of warm compaction can significantly reduce the compaction pressure needed to achieve a high relative density of the titanium and titanium powder compacts. The effect of temperature on relative density is attributed to the decrease of yield stress of the powder material with increasing temperature. The mechanisms of warm compaction also depend on the shapes and sizes of the titanium and titanium alloy powders. It is demonstrated that titanium and titanium alloy powder compacts with a high relative density can be sintered rapidly by induction heating, with the initial stage of sintering being completed within a few minutes, and in the meantime, the increased green density of powder compacts achieved by warm compaction is also favorable for increasing the relative density achieved by pressureless sintering.