Effect of Compaction Temperature on Sinterability of Magnesium and Aluminum Powder Mixtures by Warm Compaction Method

抄録

An oxide film is easily formed on the surface of magnesium and aluminum powders due to the high chemical reactivity of these metals. The sinterability of these powders is extremely poor for conventional powder metallurgy. At present, the behavior of the warm compaction method, which has been done using iron powder, is practically very interesting, because high density and strongly sintered materials are efficiently obtained. However, there are only a few reports on the sinterability of magnesium and aluminum powder mixtures by this method. In this study, to consider the sinterability of such mixtures, we examined the effect of the compaction temperature. The compacts that consist of these mixtures were consolidated by the warm compaction method, which was conducted in the temperature range from 301 to 423 K. The compacts were sintered in an argon atmosphere. As a result, the transverse rupture strength for the warm compaction was from 20 to 30 MPa higher than for the cold compaction. The increasing compaction temperature causes sufficient contact between the powder particles, and at the same time, plastic deformation of the powder particles readily occurs. This behavior induced by the warm compaction method would lead to a break down of the oxide films. As a result, sufficient bonding between the powder particles occurred, and the transverse rupture strength increased.