加热方式对Zr48Cu36Ag8Al8块体非晶合金晶化机制的影响

Effect of heating method on crystallization of Zr48Cu36Ag8Al8 bulk metallic glass

采用铜模吸铸法制备了Zr48Cu36Ag8Al8块体非晶合金,并利用同步示差扫描量热仪(DSC)对其晶化动力学进行研究。结果表明:通过对不同升温速率下的DSC曲线进行分析,根据Kissinger方程计算获得的Zr48Cu36Ag8Al8非晶合金的晶化激活能约为239 k J/mol;而根据经典JMA模型,通过对在过冷液相区内不同温度(703~743 K)的等温DSC曲线进行计算获得的等温晶化激活能为341 k J/mol,造成的差异主要归因于高温区与低温区晶化机制的差异。此外,通过对比晶化产物的组织相貌,还发现不同加热方式组织的生长速率的控制方式不同。

Zr48Cu36Ag8Al8 bulk metallic glass was prepared by copper die suction casting,and its crystallization kinetics was studied by means of synchronous differential scanning calorimeter(DSC).The results show that the crystallization activation energy of Zr48Cu36Ag8Al8 bulk metallic glass is about 239 k J/mol based on the DSC curve at different heating rate.According to the classic JMA model,isothermal activation energy of 341 k J/mol is obtained by calculating isothermal DSC curves at different temperatures(703-743 K)in the supercooled liquid region,which is mainly attributed to the difference in crystallization mechanism between the high temperature zone and the low temperature zone.In addition,by comparing the morphologies of the crystallization products,it’s also found that the growth rate of the microstructure is controlled differently by different heating methods.