论文部分内容阅读
采用铜模吸铸法制备了Cu50.3Zr49.7-xNbx(x=0,2)块体非晶合金。利用示差扫描量热分析(DSC)研究了2at%Nb的添加对Cu-Zr非晶合金在过冷液相区等温晶化行为的影响。结果显示Cu基合金的等温晶化动力学符合JMA方程的定量描述。含微量Nb的合金具有更长的晶化孕育时间、更宽的反应放热峰以及更低晶化速率常数k和Avrami指数n,与此同时局域Avrami指数n随晶化体积分数的变化和Nb的添加而改变。这表明微量Nb添加在抑制合金形核,提高其热稳定性的同时,也改变了Cu基合金的等温晶化过程。
Cu50.3Zr49.7-xNbx (x = 0,2) bulk amorphous alloy was prepared by copper mold suction casting. The effect of 2 at% Nb addition on the isothermal crystallization behavior of Cu-Zr amorphous alloy in supercooled liquid region was investigated by differential scanning calorimetry (DSC). The results show that the isothermal crystallization kinetics of Cu-based alloys conform to the quantitative description of the JMA equation. The alloys containing trace Nb have longer crystallization incubation times, broader reaction exothermic peaks, and lower crystallization rate constants k and Avrami index n, while the variation of local Avrami index n with the crystallization volume fraction and Nb addition changes. This shows that the addition of trace Nb inhibits the nucleation of the alloy to improve its thermal stability, but also changes the isothermal crystallization process of the Cu-based alloy.