Effect of heat treatments at 520 °C on an aluminium alloy matrix composite reinforced with Ni3Al powder particles

The effect of heat treatment at 520 °C on Si and Mg in 6061/5% volume Ni3Alp composite was investigated. Si atoms diffused through the Al3Ni reaction product to form a Si-containing Al3Ni2 phase with variable amounts of Si, whereas Mg accumulated at matrix-Al3Ni interphases. As a consequence, the 6061 alloy lost its age hardenability.