Isothermal crystallization in Ce_(70)Ga_6Cu_(24) bulk metallic glass  

作　　者：JIANG WeiXin ZHANG Bo 

机构地区：[1]School of Material Science and Engineering, Hefei University of Technology [2]Anhui Provincial Key Lab of Functional Materials and Devices, Hefei University of Technology

出　　处：《Science China(Physics,Mechanics & Astronomy)》2014年第10期1870-1874,共5页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.51171055 and 51322103)

摘　　要：The isothermal crystallization behaviors in a newly developed CeGaCu bulk metallic glass have been investigated through the classic differential scanning calorimeter （DSC） method. It is found that the apparent activation energy （Ea） strongly depends on the fraction （x） of isothermal crystallization. Johnson-Mehl-Avrami （JMA） formula was used to analyze the mechanism of crystallization and the obtained Avrami exponent （n） was discovered to show an obvious correlation with the crystallization fraction x. With the help of the relation between Ea and n, the nucleation and growth activation energies, En and Eg, were estimated to be 214-304 kJ/mol and 91 kJ/mol, respectively. This result suggests that the main energy barrier against crystallization in the present glass should be the nucleation of nucleates, rather than the growth of crystals. Such a large E, is also believed to be responsible for the good glass forming ability of the CeGaCu alloy.The isothermal crystallization behaviors in a newly developed CeGaCu bulk metallic glass have been investigated through the classic differential scanning calorimeter(DSC) method. It is found that the apparent activation energy(Ea) strongly depends on the fraction(x) of isothermal crystallization. Johnson-Mehl-Avrami(JMA) formula was used to analyze the mechanism of crystallization and the obtained Avrami exponent(n) was discovered to show an obvious correlation with the crystallization fraction x. With the help of the relation between Ea and n, the nucleation and growth activation energies, En and Eg, were estimated to be 214–304 kJ/mol and 91 kJ/mol, respectively. This result suggests that the main energy barrier against crystallization in the present glass should be the nucleation of nucleates, rather than the growth of crystals. Such a large En is also believed to be responsible for the good glass forming ability of the CeGaCu alloy.

关 键 词：Ce-based bulk metallic glass activation energy Avrami exponent nucleation and growth 

分 类 号：TQ171.1[化学工程—玻璃工业]