Sm对AZ91D合金显微组织与力学性能的影响  

Effects of Sm on microstructure and mechanical property of AZ91D alloy

作　　者：黄正华[1] 刘汪涵博 戚文军[1] 徐静[1] 

机构地区：[1]广州有色金属研究院,广州510650 [2]中南大学材料科学与工程学院,长沙410083

出　　处：《中国有色金属学报》2015年第10期2649-2655,共7页The Chinese Journal of Nonferrous Metals

基　　金：国家高技术研究发展计划资助项目(2013AA031001);粤港共性技术招标资助项目(2013B010138001)

摘　　要：利用光学显微镜、扫描电子显微镜和x射线衍射仪分析铸态和固溶态AZ91D-xSm（x=0～11合金的组织和相组成，测试其室温拉伸力学性能和冲击韧性。结果表明：随着Sm含量的增加，铸态组织中不连续网状β-Mg17Al12相发生破碎，数量逐渐减少，而小块状高热稳定性新相A12Sm数量逐渐增多；拉伸力学性能和冲击韧性整体均逐渐提高，AZ91D．0．88Sm合金的抗拉强度吣伸长率d和冲击韧性anK分别达到230MPa、15．5％和24J／cm2；经固溶处理后，β-Mg17Al12相完全固溶于a-Mg基体中，只存在Al2Sm相；拉伸力学性能和冲击韧性均明显提高，但其提高幅度随着Sm含量的增加而有所减缓。The microstructures and phase compositions of as-cast and solution-treated AZ91D-xSm （x=0-1） alloys were investigated by optical microscopy, scanning electron microscopy and X-ray diffractometry. Meanwhile, the tensile mechanical property and impact toughness at ambient temperature were tested. The results show that the discontinuous network β-Mg17Al12 phase breaks and decreases gradually among the as-cast microstructure with increasing the Sm content. Meanwhile, small block A12Sm new phase with high thermal stability increases gradually. The tensile mechanical property and impact toughness on the whole are enhanced gradually. Tensile strength σb, elongation δ and impact toughness ank of AZ91D-0.88Sm alloy reach 230 MPa, 15.5% and 24 J/cm2, respectively. After solution treatment, β-Mg17Al12 phase dissolves into a-Mg matrix completely and A12Sm phase still exists. The tensile mechanical property and impact toughness are enhanced obviously and the improving amplitude decreases slightly with increasing the Smcontent.

关 键 词：AZ91D合金 Sm变质 显微组织 拉伸力学性能 冲击韧性 

分 类 号：TG146[一般工业技术—材料科学与工程]