挤压态X20镁合金固溶处理过程中Al_2Ca的形成机理(英文)  

Formation of Al_2Ca Phase in as-Extruded X20 Magnesium Alloy by Solution Treatment

作　　者：谢辉[1,2] 贾磊[1] 张金龙 王智民[1] 吕振林[1] 

机构地区：[1]西安理工大学,陕西西安710048 [2]兰州理工大学甘肃省有色金属新材料重点实验室,甘肃兰州730035 [3]西安航空高等专科学校,陕西西安710077

出　　处：《稀有金属材料与工程》2012年第6期958-961,共4页Rare Metal Materials and Engineering

基　　金：Outstanding Doctoral Dissertation Foundation of Xi’an University of Technology (101-2111004);Open Foundation from State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials (SKL07006);Shaanxi Provincial Project of Special Foundation of Key Disciplines

摘　　要：对Ca含量为2wt%的挤压态X20镁合金在410 ℃固溶处理20 h,采用光学显微镜 (OM)、扫描电镜 (SEM) 结合能谱分析 (EDS)以及透射电镜 (TEM) 对固溶处理前后的组织进行了表征,利用XRD衍射仪考察了固溶处理前后合金的相组成。结果表明,经固溶处理后,合金初始组织中β-Mg17Al12相的数量明显减少,同时析出新相Al2Ca。Al2Ca的形成可归结于残余β-Mg17Al12中高的Ca原子所造成的Mg原子被Ca原子取代,同时Al2Ca相自身高的结构稳定性也是其在Mg-Ca和Al-Ca系竞争析出中胜出的原因。The as-extruded X20 magnesium alloys containing 2.0wt% Ca were solution-treated at 410 ℃ for 20 h. The microstructures before and after solution treatment were observed by optical microscope （OM）, scanning electron microscope （SEM） together with an energy dispersive spectroscope （EDS）, and transmission electron microscope （TEM）. The phase compositions before and after solution treatment were confirmed by X-ray diffraction （XRD）. The results show that the amount of β-Mg17Al12 phases decreases remarkably after solution treatment, and new Al2Ca phases are formed. The formation of A12Ca phase might be due to high concentration of Ca atoms in residual β-Mg17Al12 phases, which leads the place of Mg atoms to be substituted by Ca. On the other hand, Al2Ca phase could be also described as a completing product between Al-Ca system and Mg-Ca system intermetallics due to its high structural stability.

关 键 词：挤压态镁合金 组织 金属间化合物 Al2Ca 相确定 

分 类 号：TG156.94[金属学及工艺—热处理]