A novel way of amorphous phase formation during mechanical alloying of copper and cadmium powders

Phase formation during high-energy ball milling of copper and cadmium powders has been investigated. Both X-ray diffractometry (XRD) and differential scanning calorimetry (DSC) have been used to characterize the resulting phases. An amorphous phase forms during milling in the copper-cadmium system by a reaction between the equilibrium delta phase and one of the constituent metals (copper). However, the amorphous phase cannot be produced by a direct reaction between the copper and cadmium powders, nor by milling of a powder consisting of only the delta phase. It appears most likely that the contribution from the generated copper/delta interfaces, and the accompanying increase in the total free energy, provide the additional driving force for the amorphous phase formation in: this system.