Mg-Al-Sm系变形镁合金的组织与力学性能

发布时间：2018-03-02 12:11

本文选题：变形镁合金　切入点：Mg-Al-Sm系　出处：《稀有金属》2017年11期 　论文类型：期刊论文

【摘要】：镁合金在汽车、通讯电子和航空航天领域正得到日益广泛的应用,其中变形镁合金呈现出比铸造镁合金更优异的性能,但其强韧性仍有待于提高。利用光学显微镜(OM)、扫描电子显微镜(SEM)和X射线衍射仪(XRD)分析了铸态和挤压态Mg-6.02Al-1.03Sm和Mg-5.95Al-1.01Sm-0.57Zn合金的组织和相组成,并测试了其室温和高温拉伸力学性能。结果表明,上述合金的铸态组织均由α-Mg基体、不连续网状β-Mg17Al12相和小块状化合物Al2Sm组成,后者合金中添加的Zn固溶于α-Mg基体和β-Mg17Al12相中;铸态合金呈现较优异的拉伸力学性能,如室温抗拉强度σb、屈服强度σ0.2和伸长率δ分别处于220~235 MPa,118~123 MPa和12.5%~16.0%。经热挤压后,合金组织显著细化,再结晶晶粒的平均尺寸仅为12~14μm,Al2Sm相亦有所破碎;挤压态合金的拉伸力学性能显著提高:室温σb和σ0.2分别提高至300~320MPa和215~230 MPa,423 K时的高温σb,σ0.2和δ分别提高至205~215 MPa,161~166 MPa和42.0%~44.0%。
[Abstract]:Magnesium alloys are increasingly widely used in automotive, communication electronics and aerospace fields, in which wrought magnesium alloys exhibit better properties than cast magnesium alloys. But its strength and toughness still need to be improved. The microstructure and phase composition of as-cast and extruded Mg-6.02Al-1.03Sm and Mg-5.95Al-1.01Sm-0.57Zn alloys were analyzed by optical microscope, scanning electron microscope (SEM) and X-ray diffractometer (XRD). The tensile mechanical properties at room temperature and high temperature were also measured. The results showed that the as-cast microstructure of the alloys was composed of 伪 -Mg matrix, discontinuous 尾 -Mg17Al12 phase and small block compound Al2Sm, in which Zn solid solution was found in 伪 -Mg matrix and 尾 -Mg17Al12 phase. The as-cast alloys show excellent tensile mechanical properties, such as tensile strength 蟽 _ b at room temperature, yield strength 蟽 _ 0.2 and elongation 未 at 220 ~ 235MPA ~ (118) ~ (123) MPa and 12.5 ~ 16.0, respectively. After hot extrusion, the microstructure of the alloy is significantly refined. The average grain size of recrystallized grain is only 12 ~ 14 渭 m Al _ 2Sm phase and the tensile mechanical properties of extruded alloy are improved remarkably: 蟽 _ b and 蟽 _ (0.2) are increased to 300 ~ 320MPa at room temperature, and 蟽 _ (0.2) and 未 ~ (2) to 205151MPA 161166 MPa and 42.0 ~ 44.0K at room temperature, respectively.
【作者单位】：广东省科学院广东省材料与加工研究所;
【基金】：广东省金属强韧化技术与应用重点实验室(2014B030301012) 广州市先进金属结构材料重点实验室(201509010003) 广东省自然科学基金(2016A030313802) 广东省高新技术产业化项目(2013B010102021) 广东省产学研合作项目(2014B090903016) 粤港共性技术招标项目(2013B010138001) 广东省科技型中小企业技术创新项目(2016A010120024)资助
【分类号】：TG146.22

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