Effects of Compaction Velocity on the Sinterability of Al-Fe-Cr-Ti PM Alloy.

In this research, the effects of the compaction velocity on the sinterability of the Al-Fe-Cr-Ti powder metallurgy (PM) alloy by high velocity compaction were investigated. The Al-Fe-Cr-Ti alloy powder was compacted with different velocities by high velocity compaction and then sintered under a flow of high pure (99.999 wt%) nitrogen gas. Results indicated that both the sintered density and mechanical properties increased with increasing compaction velocity. By increasing the compaction velocity, the shrinkage of the sintered samples decreased. A maximum sintered density of 2.85 gcm-3 (relative density is 98%) was obtained when the compaction velocity was 9.4 ms-1. The radial and axial shrinkage were controlled to less than 1% at a compaction velocity of 9.4 ms-1. At a compaction velocity of 9.4 ms-1, sintered compacts with an ultimate tensile strength of 222 MPa and a yield strength of 160 MPa were achieved. The maximum elongation was observed to be 2.6%. The enhanced tensile properties of the Al-Fe-Cr-Ti alloy were mainly due to particle boundary strengthening.