Kinetics of structural evolution in immiscible Ag-Cu and Co-Cu systems under mechanical processing conditions

The effects of mechanical processing by ball milling on powder mixtures consisting of immiscible elements were studied. Equiatomic Ag-Cu and Co-Cu mixtures were subjected to mechanical treatment at different values of milling intensity. The kinetics of structural evolution were characterized by means of X-ray diffraction analyses taking advantage of the Rietveld method. The evolution processes followed sigmoidal trends, the rate of evolution being proportional to the milling intensity and thereby connected with the impact energy. A threshold impact energy was determined below which no structural evolution is observed.