Al-Cu-Fe系初生准晶相凝固过程的热力学分析  

Thermodynamic analyses on solidification process of primary Al-Cu-Fe icosahedral quasicrystal phase

作　　者：赵东山[1] 沈宁福[1] 郭新勇[2] 瞿文榜[3] 孙丽虹[4] 

机构地区：[1]郑州大学材料工程学院,郑州450002 [2]河南大学特种功能材料重点实验室,开封475001 [3]武汉大学物理系,武汉430072 [4]北京有色金属研究总院,北京100088

出　　处：《中国有色金属学报》2004年第2期162-167,共6页The Chinese Journal of Nonferrous Metals

基　　金：河南大学特种功能材料重点实验室开放课题资助项目(9926)

摘　　要：采用XRD,SEM和TEM等方法,研究了铸态Al58.8Cu36.6Fe3.5Si1.1合金(973K保温2.5h后水淬)的显微组织及相组成。观察到铸态样品中存在4种不同的相,即初生准晶I相、Φ相、θ Al2Cu相和η AlCu相。对准晶I相及其晶体近似相R相,提出相应的自由能计算模型及算法,从理论上说明准晶(Al61.89Cu25.61Fe11.10)I相是高温稳定相,当温度低于938K时,将形成其晶体近似相R相。The microstructures and constituent phases of the Al_(58.8)-(Cu_(36.6)Fe_(3.5))Si_(1.1) alloy, water quenched after retaining 2.5 h at 973 K, were examined by means of optical metallography , scanning electron microscopy, transmission electron microscopy and X-ray diffraction analyses. The investigation reveals that the constituent phases of the Al_(58.8)Cu_(36.6)Fe_(3.5)Si_(1.1) alloy are the I phase,  phase, η(AlCu) phase and θ(Al_2Cu) phase. A thermodynamic model and the calculation method of the change of Gibbs free energy during the primary solidification for the icosahedral quasicrystal phase and its approximant crystal phase are proposed. The thermodynamic analyses show that the icosahedral quasicrystal phase solidifies as a primary stable phase when temperature is higher than 938 K. Below 938 K, its approximant crystal phase emerges.

关 键 词：热力学 凝固组织 初生准晶相 自由能 铝合金 XRD SEM TEM 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG111.4[金属学及工艺—金属材料]