铸态和固溶态Mg-Sn二元合金的组织与力学性能  

Microstructures and mechanical properties of as-cast and solution-treated Mg-Sn binary alloys

作　　者：黄正华[1] 戚文军[1] 徐静[1] 蔡畅[1] 

机构地区：[1]广东省工业技术研究院(广州有色金属研究院),广东广州510650

出　　处：《材料研究与应用》2014年第4期221-227,共7页Materials Research and Application

基　　金：国家高技术研究发展计划(863计划)(2013AA031001);院博士启动基金(2013B003)

摘　　要：分析了铸态和固溶态Mg-xSn（x=2.18-6.54）合金的组织,测试了其拉伸力学性能、硬度及冲击韧性.结果表明,随着Sn含量的增加,铸态组织中粗大树枝晶状α-Mg逐渐细化,Mg2Sn相逐渐增多,并且趋于连续网状分布于晶界处.室温下合金铸态拉伸力学性能及冲击韧性表现为先提高后降低,具有最佳性能的Mg-3.52Sn合金的抗拉强度σb、延伸率δ和冲击韧性值αnK分别为151 MPa,12.5%和10J/cm2;高温（423K）时σb和δ先分别逐渐提高至Mg-3.52Sn合金的87MPa和19.0%,经略有降低后又分别逐渐提高至Mg-6.54Sn合金的92 MPa和15.5%.经固溶处理后,Mg2Sn相完全固溶于α-Mg基体中;室温下拉伸力学性能有所提高,而高温下拉伸力学性能基本保持不变;在Sn含量低和高时冲击韧性分别降低和提高.Microstructures of as-cast and solution-treated Mg-xSn（x=2.18-6.54）alloys were investigated.Meanwhile,the tensile mechanical property,hardness and impact toughness were tested.The results show that the coarseα-Mg dendrite among the as-cast microstructure is refined gradually with increasing the Sn content.Meanwhile,Mg2 Sn phase increases gradually and tends to distribute along grain boundary in the form of continuous network.As-cast tensile mechanical property and impact toughness at ambient temperature are increased initially,and then reduced.Tensile strengthσb,elongationδand impact toughness valueαnKcan reach 151 MPa,12.5% and 10J/cm2 for Mg-3.52 Sn alloy with the most excellent best property,respectively.At the elevated temperature of 423 K,σbandδfirst increase to 87 MPa and 19.0%for Mg-3.52 Sn alloy,respectively,then decrease slightly,and finally increase to 92 MPa and 15.5% again for Mg-6.54 Sn alloy,respectively.After solution treatment,Mg2 Sn phase dissolves intoα-Mg matrix completely.The tensile mechanical property is enhanced slightly and remains almost unchanged at ambient and elevated temperatures,respectively.The impact toughness is reduced and enhanced for the low and high Sn contents,respectively.

关 键 词：耐热镁合金 Mg-Sn二元合金 组织 力学性能 

分 类 号：TG146[一般工业技术—材料科学与工程]