Alloy Development and Microstructural Evolution during Sintering of a PM AI-Cu-Mg-Si Alloy

摘要

Relevant reactions occurring during liquid phase sintering of an Al-4.4Cu-0.5Mg-0.7Si (wt %) P/M alloy have been mainly identified by means of DSC, dilatometry, sintering experiments and microstructural analysis including EDS. The first reaction observed is the formation of an Al-Mg liquid appearing at about 450 ℃. This reaction is followed by other reactions at 505 and 550℃ related to the incorporation of Cu into the liquid phase at the same time that Mg, Si and Cu diffuse into the solid Al particles. The chemical homogenisation of the alloy and the spreading of the liquid phase produce swelling of the powder compact during the initial sintering stage.