S.S Razavi.Tousi - Materials & Energy Research Center,
R .Yazdani.Rad

Mechanical alloying, though a well known technique for materials synthesis, often suffers from impurity interference. Nature and origins of major impurities and their effect on properties of nano-grained Al and Al/Al2O3 composites prepared in a fast mill has been investigated. Carbon and oxygen from PCA and Fe from vial erosion were found to be the main impurities affecting structural properties such as lattice parameter and melting point of the milled mixture. An attempt was made to assess the effect of impurities on mechanical properties of the products using some common experimental techniques as DTA, XRD, SEM and TEM. It was found that the influences of nano-grained structure together with dispersoids caused by PCA on improvement of mechanical properties are greater than that resulted from the alumina reinforcement particles.

high-energy milling, nanostructures; mechanical properties; contamination