Distribution control of AlN particles in Mg-Al/AlN composites

A new process for the preparation of ultrafine AlN particles reinforced Mg-Al matrix composites was proposed to control the agglomeration of ultrafine AlN particles. The influence of mechanical milling on the modification of reinforcement particles and the refinement of matrix alloy particles was also investigated. Particles barriers for uniform distribution into matrix grain interiors in P/M process were analyzed. For AlN-Mg mixture, AlN particles were separately cladded in Mg coating and homogeneously distributed in the mixture after milling for 15 h. Mg-Al matrix alloy particles were significantly refined after milling for 20 h, and the strip-type Al was fragmented and uniformly distributed in Mg matrix. There are three critical factors controlling the agglomeration of ultrafine AlN reinforcement in Mg-Al matrix. Finally a fully homogeneous intragranular distribution of AlN particles in Mg-Al matrix was obtained.