STRUCTURAL-CHANGES INDUCED BY THE MECHANICAL ALLOYING OF CRYSTALLINE METAL POWDERS

We report structural results of mechanical alloying binary mixtures of pure elemental powders as a function of milling time. X-ray line broadening techniques are used to follow the lattice destabilization caused by interdiffusion of elements, which is favoured by a negative heat of mixing. Experimental evidence is outlined on the formation of highly distorted solid solutions and intermetallic compounds, which, due to the milling action, collapse to an amorphous condition when a critical density of defects is reached.