Crystallization Kinetics of a High-zirconium-based Glassy Alloy：A DSC Study

The non-isothermal and isothermal crystallization kinetics of Zr_（72.5）Al_（10）Fe_（17.5） glassy alloy was investigated using differential scanning calorimeter（DSC）.Under non-isothermal heating condition,the primary phase in the initial crystallization is Zr_6Al_2Fe phase and the final crystallized products consist of Zr_6Al_2Fe,Zr_2Fe and a-Zr phases.The apparent activation energy for crystallization estimated using the Kissinger method is 342.1 ±8.1 kJ/mol.The local activation energy decreased with the increase in the crystallization volume fraction during nonisothermal crystallization.Under isothermal heating condition,the average Avrami exponent of about 2.76 implies a mainly diffusion-controlled three-dimensional growth with an increasing nucleation rate.The local activation energy for isothermal crystallization shows a different variation trend from that for nonisothermal crystallization,indicating different nucleation-and-growth mechanisms for the two crystallizaiton conditions.