Cu_(48)Zr_(45)Al_7金属玻璃非等温晶化动力学研究  

Non-Isothermal Crystallization Kinetics of Cu_(48)Zr_(45)Al_7 Metallic Glass

作　　者：高谦[1] 坚增运[1] 翟逸玥 王凯[1] 贾婷婷[1] 

机构地区：[1]西安工业大学材料与化工学院,西安710021

出　　处：《西安工业大学学报》2016年第10期830-835,共6页Journal of Xi’an Technological University

基　　金：国家重点基础研究发展计划(2011CB610403);国家自然科学基金(51171136;51051115);陕西省科技厅自然科学基金(2012JM6010)

摘　　要：为了解决金属玻璃的稳定性问题,分析了Cu基金属玻璃的晶化动力学特征.采用单辊急冷法制备了Cu48Zr45Al7非晶带材,用X射线衍射仪和差示扫描量热仪对试样的非晶结构和特征温度进行了测试.根据VF方程确定了试样的动力学理想玻璃转变温度T0,通过Kissinger、Moynihan和Kissinger-Akahira-Sunose方程分别计算了玻璃转变激活能Eg、开始析晶激活能Ex和局部激活能Eα,并研究其稳定性问题.研究结果表明:玻璃转变温度Tg和开始析晶温度Tx随升温速率的变化具有明显的动力学特征,且T0等于649.4K.基于不同理论模型的Kissinger和Moynihan方程计算出的激活能在误差范围内(±12kJ·mol-1),其结果相一致.当晶化体积分数α<0.5时,局部激活能Eα近似为常数(324±5)kJ·mol-1,表明晶化过程克服恒定的阻力能垒;当α>0.5时,Eα从329.3kJ·mol-1单调减小为282.6kJ·mol-1,晶化过程需要克服的能垒逐渐减小,晶化过程越易进行.To solve the problem of the stability of metallic glass, crystallization kinetics of Cu-based metallic amorphous alloy was investigated. The Cu48 Zr45 A17 metallic glass ribbons were successfully prepared by means of melt-spinning method. The sample structure and characteristic temperatures were tested using X-ray diffraction （XRD） and differential scanning calorimetry （DSC）. Kinetic ideal glass transition temperature To was determined by Vogel- Fulcher （VF） equation and glass transition activation energy Eg and onset crystallization activation energy Ex were obtained by Kissinger and Moynihan equations Besides, Kissinger-Akahira-Sunose （KAS） equation was used to obtain local activation energy Eo. The problem of stability was studied by these activation energies. It is found：The variation of glass transition temperature Tg and onset crystallization temperature Tx with heating rate is a manifestation of the kinetic effect and To is equal to 649.4 K. The calculated activation energies using Kissinger equation agree with that of Moynihan equation within errors （± 1Z kJ mol-1）, although these equations are based on different theoretical methods. Local activation energy E, remains approximately a constant value （324＋5） kJ mol-1 ,which suggests that crystallization overcomes a constant barrier at crystallized volume fraction a〈0. 5; While Eo monotonously reduces, which indicates that crystallization overcomes a decreasing barrier and increasingly easy with increased a at a〉0.5.

关 键 词：金属玻璃 激活能 晶化体积分数 晶化动力学 玻璃转变温度 

分 类 号：TG139.8[一般工业技术—材料科学与工程]