Evaluation of crystallization behavior of Mg65Cu30-xAgxY5 (x=1, 4, 7, 10) amorphous alloys produced by melt-spinning method

In the present work, the effects of substitution of Ag with Cu on thermal behaviors of Mg-Cu-Y based amorphous alloys were investigated. In this regards, four different (x=1, 4, 7, 10) Mg65Cu30-xAgxY5 alloys were melt spinned at same condition. The structural and thermal characteristics of prepared alloys were examined using X-ray diffraction (XRD) and differential scanning calorimetric (DSC) techniques. Based on results, the substitution of Ag with Cu in Mg-Cu-Y alloys had significant effects on thermal behavior of prepared samples. Although, the crystallization mechanism of prepared amorphous phase in different alloys was the same, the Mg65Cu23Ag7Y5 alloy (in the presence of 7 at. % of Ag) showed higher thermal stability in comparison to others. The crystallization activation energy of prepared amorphous alloys was estimated about 150-200 kJ mol-1. Based on the calculated values of Avrami exponent (1.5<n<1.7), the crystallization process in different systems were the same as a three-dimensional diffusion-controlled growth.