Mg-10Gd-4.8Y-0.6Zr合金在520℃下的固溶处理行为  

Behavior of Mg-10Gd-4.8Y-0.6Zr alloy during solution heat treatment at 520 ℃

作　　者：李慧中[1,2] 郭菲菲[1] 刘楚明[1] 刘洪挺[1] 王海军[1] 梁霄鹏[1] 赵家彦[3] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]中南大学粉末冶金国家重点实验室,长沙410083 [3]中南大学地球科学与信息物理学院,长沙410083

出　　处：《粉末冶金材料科学与工程》2011年第3期323-328,共6页Materials Science and Engineering of Powder Metallurgy

基　　金：国防重大基础研究项目(2005年);中南大学博士后基金资助项目(2007-08);中国博士后基金资助项目(20070420828)

摘　　要：采用光学显微镜(OM)、扫描电镜(SEM)、透射电镜(TEM)、显微硬度测试、热分析、能谱分析以及X射线衍射(XRD)等手段,研究Mg-10Gd-4.8Y-0.6Zr合金铸态和520℃固溶处理不同时间后的显微组织以及显微硬度分布。结果表明:Mg-10Gd-4.8Y-0.6Zr合金经520℃/16 h固溶处理后,铸态时的网状共晶完全溶解到基体中,Gd、Y富集的立方体相弥散分布在晶内;晶内偏析消除,硬度有所降低。合金在固溶处理过程中发生以下组织演变:α-Mg固溶体+网状Mg24(GdY)5相→α-Mg固溶体+断续破碎的Mg24(GdY)5相→α-Mg过饱和固溶体+立方体相。该合金在520℃固溶处理的适宜时间为16 h。The microstructure and microhardness distribution of Mg-10Gd-4.8Y-0.6Zr alloy both in the as-cast condition and after solution heat treatment were studied by optical microscopy（OM）,scanning electron microcopy（SEM）,transmission electron microscopy（TEM）,microhardness test,differential scanning calorimetry,energy dispersive spectrometer（EDS）and X-ray diffraction.The results indicate that after solution heat treatment at 520 ℃,the network-like eutectic compounds in cast alloy are completely dissolved into the Mg matrix,and the cuboid-shaped RE-rich phase dispersives in the matrix.Since the intragranular segregation has relieved,the hardness is decreased.The evolution of microstructure in homogenizing treatment involves α-Mg solid solution＋Mg24（GdY）5 eutectic phase→α-Mg solid solution＋disconnected and fragmentized Mg24（GdY）5 phase→α-Mg supersaturated solid solution＋cuboid-shaped phase.The fitting solution-treated time of the alloy at 520 ℃ is 16 h.

关 键 词：Mg-10Gd-4.8Y-0.6Zr合金 固溶处理 显微组织 硬度 组织演变 

分 类 号：TG146[一般工业技术—材料科学与工程]