Cu-Zr-Ag-Al非晶的晶化动力学研究

利用差示扫描热分析法(DSC)和X射线衍射仪(XRD),并借助Kempen模型和Kissinger方程,研究了不同加热速率下Cu45 Zr45 Ag7Al3非晶合金晶化过程及非等温晶化动力学.在连续加热条件下,随升温速率的加快,Cu45Zr45Ag7Al3非晶合金的特征温度Tg,Tx和Tp均向高温区移动,且过冷液相区间扩大.计算了该合金的激活能,分别为Eg=431.1kJ/mol,Ex=307.2 kJ/mol和Ep=339.5 kJ/mol；并计算出相应的Avrami指数n(分别为5.2和1.9),表明该非晶合金的晶化是以界面控制的多晶型晶化为主.

Kinetics of Crystallization in Cu-Zr-Ag-Al Amorphous Alloy

Crystallization transformation kinetics of Cu45Zr45Ag7Al3 bulk metallic glasses in non-isothermal (continuous heating) modes were investigated by differential scanning calorimetry (DSC). Activation energy for crystallization at different crystallized volume fractions was analyzed in Kissinger method. Then non-isothermal transformation kinetics was described with the Kempen model. Under the condition of continuous heating, the characterization temperature Tg,Tx and Tp of amorphous alloy Cu45Zr45Ag7Al3 increase with the heating rate, and the super-cooled liquid phase zone also expands gradually. The activation energies of Cu45Zr45 Ag7 Al3 bulk metallic glasses are 431.1, 307.2, 339.5 kJ·mol-1 and the exponent n are 5.2 and 1.9. The results have indicated that the crystallization processes for all the glassy alloys are polymorphic crystallization controlled by interface.