The matrix powders were obtained from a commercial bar AA 7075- T6. The bar was annealed for 48 h at 415 oct 5 c in a Felisa furnace followed by a slow cooling in order to remove the high hardness caused by the T6 heat treatment. During this heat treatment it is promoted the presence of stable m (Mgzn2) phase instead of (Mgzn), lowering the hardness of the alloy by this way.The matrix powders were obtained by