Mg-xCa-5Zn-3Al-0.2Mn镁合金砂型铸造组织和力学性能研究  

Study on the Microstructures and Mechanical Properties of Mg-xCa-5Zn-3Al-0.2Mn Sand-Casting Alloy

作　　者：杨光昱[1] 介万奇[1] 郝启堂[1] 

机构地区：[1]西北工业大学,陕西西安710071

出　　处：《稀有金属材料与工程》2006年第2期217-222,共6页Rare Metal Materials and Engineering

基　　金：国家重大基础研究项目("973")(G2000067202)

摘　　要：研究发现,Mg-5Zn-3Al-0.2Mn合金的砂型铸造组织相组成为δ-Mg基体和τ(Mg32(Al,Zn)49)化合物。在343℃固溶17h后淬火,合金组织完全转变为固溶体,力学性能最佳,σb=245MPa,δ=12%。合金中加入xCa后,组织发生变化。当x=0.43%(质量分数)时,相组成为δ-Mg+Mg-Zn-Al-Ca复杂化合物相。当x=0.95%和1.80%时,相组成为Mg-Zn-Al-Ca相+δ-Mg+Al2Ca。随着x增加,铸态合金室温力学性能呈下降趋势。加Ca合金在350℃固溶17h后淬火,室温力学性能有所提高,而σb250o和σ02.520o则随x增加而稳步提高。As sand-cast microstructure of Mg-5Zn-3Al-0.2Mn magnesium alloy contains δ-Mg and τ（Mg32 （Al, Zn） 49） phases. The τ phase is fully dissolved, into δ-Mg matrix after annealed at 343℃ for 17 h. Meanwhile the room temperature mechanical properties reach the maximum values, i.e., σb=245 MPa, δ=12%. By adding Ca into the experimental alloy,τr phase is gradually replaced by Mg-Zn-Al-Ca complex compound when Ca content is 0.43wt%, or Al2Ca and Mg-Zn-Al-Ca compound and δ-Mg when Ca content was over 0.95wt%. With the increase of Ca content, the grain of δ-Mg is refined apparently but the room temperature mechanical properties （σb and δ） decrease gradually. The room temperature mechanical properties slightly increase when the Ca modified alloys are quenched after annealed at 350℃ for 17 h, and meanwhile σb^250°and σ0.2^250°increase with the increase of Ca content.

关 键 词：组织 力学性能 铸造镁合金 高温强度 固溶处理 

分 类 号：TG27[金属学及工艺—铸造]