Aluminum Powder with Superior Sinterability under Non-pressure Process

Aluminum (Al) is one of the most important metals from an industrial viewpoint because of its superior electrical and thermal conductivity, light weight, low cost etc. However, it is well known as one of metals with low sinterability due to the thin but stable oxide layer on the particle surface. This study demonstrates the possibility of Al powder in a powder metallurgy field, especially additive manufacturing techniques, by using lanthanoid metal compounds as sintering aids. Newly developed Al gas-atomized powder recorded sintered density over 97% of that of bulk Al without any pressure, while commercially available Al gas-atomized powder became lower than 83% under the same condition. This sinterability enhancement is attributed to a novel chemical reaction route between Al particle surface and lanthanoid metal cation during the sintering event.