用差示扫描量热法研究Mg65Cu25Gd10块体非晶合金的晶化动力学

通过铜模吸铸法得到Mg65Cu25Gd10块体非晶舍金，用差示扫描量热仪（DSC）研究其晶化动力学和玻璃转变行为，玻璃转变温度Tg，晶化起始温度Tx，晶化峰值温度Tp都与加热速率有关，通过Kissinger方程可以得到表面激活能，发现晶化初始激活能Ex小于峰值激活能Ep，表明形核过程比生长过程容易，讨论了此非晶舍金的玻璃形成能力，根据JMA方程非等温模型研究了晶化动力学，Avrami参数表明在不同温度下的晶化机制是不同的．

Study of the Crystallization Kinetics of Mg65Cu25Gd10 Bulk Glassy Alloy

The bulk amorphous alloy Mg65Cu25Gd10 has been prepared by copper mold casting, The crystallization kinetics and glass transition behavior have been investigated by means of differential scanning calorimeter under non-isothermal conditions. The glass transition temperature Tg, the onset crystallization temperature Tx, and the crystallization peak temperature Teare found to depend on the heating rate during the continuous heating. The apparent activation energy Ex deduced from the Kissinger equation for the onset of crystallization is lower than Eefor crystallization peak, meaning that the nucleation process is easier than the growth. And the glass forming ability of the glass forming alloys has been discussed. Kinetics of crystallization of the bulk glassy alloy was analyzed by John-Mehl-Avrami equation with non-isothermal crystallization, The Avrami exponents indicate that the crystallization mechanism changes at different temperatures.