Mechanochemical effects in the formation of Ag50Cu50 solid solutions by mechanical alloying

This work investigates the mechanistic features of the mechanical alloying of Ag50Cu50 powder mixtures at increasingly energetic processing conditions. In all the different cases, the gradual mutual dissolution of Ag and Cu is shown to start already at the first impact. However, the composition of the resulting phases depends on the impact energy. Indirect evidences point out that the reaction is not governed by purely thermal effects. Rather, observations suggest the occurrence of coupled mechanical and chemical effects. The role of interface area available to the alloying reaction, also dependent on the impact energy, is discussed.