Applicability of Johnson-Mehl-Avrami model to crystallization kinetics of Zr_(60)Al_(15)Ni_(25) bulk amorphous alloy  

作　　者：闫志杰 党淑娥 王祥辉 廉培霞 

机构地区：[1]School of Materials Science and Engineering,Taiyuan University of Science and Technology

出　　处：《中国有色金属学会会刊：英文版》2008年第1期138-144,共7页Transactions of Nonferrous Metals Society of China

基　　金：Project(20051032)supported by the Natural Science Foundation of Shanxi Province,China;Project supported by the Shanxi Provincial Foundation for Leaders of Disciplines in Science and the Doctoral Science Foundation of Taiyuan University of Science and Technology,China

摘　　要：The applicability of Johnson-Mehl-Avrami(JMA)model to the crystallization kinetics of Zr60Al15Ni25 bulk amorphous alloy is investigated by differential scanning calorimetry(DSC)under isochronal and isothermal conditions.A criterion xm,at which a defined function z(x)exhibits the maximum value,is introduced to check the validity of JMA model to the kinetics analysis.The value of xm has a constant of 0.632 for JMA model.It is found that the values of xm at different isothermal annealing temperatures(743,748,753 and 758 K)are almost near 0.632,which indicates that the isothermal crystallization kinetics can be modeled by JMA equation.However,the values of xm at different heating rates(10,20,30 and 40 K/min)are about 0.52,implying that JMA model is not valid to the isochronal crystallization kinetics.The reason why the JMA model is not valid to the isochronal crystallization kinetics is discussed.The applicability of Johnson-Mehl-Avrami（JMA） model to the crystallization kinetics of Zr60Al15Ni25 bulk amorphous alloy is investigated by differential scanning calorimetry（DSC） under isochronal and isothermal conditions. A criterion Xm, at which a defined function z（x） exhibits the maximum value, is introduced to check the validity of JMA model to the kinetics analysis. The value Of Xm has a constant of 0.632 for JMA model. It is found that the values Of Xm at different isothermal annealing temperatures （743,748, 753 and 758 K） are almost near 0.632, which indicates that the isothermal crystallization kinetics can be modeled by JMA equation. However, the values Of Xm at different heating rates （10, 20, 30 and 40 K/min） are about 0.52, implying that JMA model is not valid to the isochronal crystallization kinetics. The reason why the JMA model is not valid to the isochronal crystallization kinetics is discussed.

关 键 词：非晶体合金 热分析 热动力学 Zr60Al15Ni25体积 

分 类 号：TG111[金属学及工艺—物理冶金]