High velocity compaction compared with conventional compaction

Abstract

Compaction to full density is a means to deliver performance and precision without the distortion associated with sintering densification. High strain rate compaction using shock waves has been demonstrated as one means to attain full density in the green state. In the present study, variations in the compaction pressure are used to determine the conditions for attaining full density and these conditions are compared between high velocity and traditional die compaction technologies. A diminishing effect of compaction pressure on densification was observed. At the same compaction pressure the green density and hardness were lower using high velocity compaction. Sound velocity measurements in the powder show high velocity compaction did not generate a shock wave. Therefore, under subcritical compaction velocity conditions there is a higher green density from conventional compaction when compared using the same peak pressure.

Keywords:

• HIGH VELOCITY COMPACTION
• COMPACTION ENERGY
• GREEN DENSITY
• ULTRASONIC TESTING
• FERROUS POWDER METALLURGY