Al4C3和Ce对AZ91D镁合金铸态显微组织和性能的影响.pdfVIP

学兔兔 铸 造 Jun．2009 FOUNDRY VOI．58 NO．6 Al4C3~llCe对AZ91 D镁合金铸态显微组织和 性能的影响 刘生发，张 元，韩 辉，杨 超，陈 阳，刘林艳 (武汉理工大学材料科学与工程学院，湖北武汉430070) 捅姜：借助SEM、EDS、XRD、DTA等研究了AhC3和Ce加入对AZ91D镁合金铸态组织和性能的影响。结果表明：加入 0．6％AhC 能显著细化合金晶粒，使粗大骨骼状13相和层片状 +B共晶组织转变为蜂窝状的部分离异共晶组织，同时13相 的尺寸变小、分布较均匀。在此基础上，复合添加O．2％Ce后细化效果更好，B相分布更趋均匀且含量减少。此外，组 织中有少量针状化合物AI4Ce形成。通过错配度计算、能谱分析以及差热分析，证实了Al4C 可成为初生ot。Mg的良好异 质核心。显微组织的细化有利于合金强度性能及耐腐蚀性能的明显提高。 关键词：AZ91D镁合金；AhE3；Ce；晶粒细化；性能 中图分类号：TG146．2+2 文献标识码：A 文章编号：1001—4977(2009)06—0546—05 Effect of AI4C3 and Ce on As--Cast Microstructure and Properties of AZ91 D Magnesium Alloy LIU Sheng-fa，ZHANG Yuan，HAN Hui，YANG Chao，CHEN Yang，LIU Lin—yah (Materials Science and Engineenng，Wuhan Univers 0f TechnoIogy，Wuhan 430070，Hubei，China) Abstract：The microstructure and performances of Az91 D alloy with Al4C3 and Ce were investigated by using of SEM，XRD，EDS and DTA．1t was found that 0．6％AI4C3 addition to AZ91 D magnesium alloy Ieads to the oc—Mg grain size obvious decreasing．the bulk skeletaI fully-divorced eutectic 13-phases and Iamellar a+B eutectic structure transforming into honeycomb—like partially-divorced eutectic 13一phases．and the 13-phases diminishing in size and uniform distribution．Combining addition Of 0．6％AI4C3 and 0．2％Ce to AZ91 D magnesium alloy resulted in beRer grain refining effect，the 13一phases breaking，reducing in amount and distributing more uniformly，furthermore a smalI amount needle．1ike compound AI4Ce were found．Based on the analysis resulting of EDS．DTA and calculation of the disregistry between AI4C3 and Mg，AI4C3 p