The interaction between the reinforcement and the matrix powders can be spotted in Fig. 9, where a zroz le seems to be trapped by matrix in the AA 7075-2 wt.% zroz composite milled by 15 h, confirming that the main mechanism the of mechanical milling in this system is based on the trapping of reinforcement particles in the grain boundaries of ductile matrix powders collide themselves and with milling media [2,3]