Al、Ca添加对Mg-Al-Ca-Mn合金组织和力学性能的影响

发布时间：2018-01-09 03:15

本文关键词：Al、Ca添加对Mg-Al-Ca-Mn合金组织和力学性能的影响　出处：《重庆大学》2015年硕士论文　论文类型：学位论文

【摘要】：研究开发具有优异性能且廉价的耐热镁合金,使其在高温条件下能满足汽车传动系统零部件的应用,已成为亟待解决的重要课题,而含有Ca的Mg-Al系合金能很好的适应这一发展趋势。本文以MA10(Mg、Mn、Al),MA11,MX10(Mg、Mn、Ca),MX11,MAX101(Mg、Mn、Al、Ca),MAX110,MAX111七种热挤压镁合金棒材和MAX(Mg-1.0t%Al-1.5wt%Ca-1.0wt%Mn)热挤压平椭圆管材为研究对象,通过观察微观组织,力学性能分析,系统研究了合金成分对沉淀相的组成、分布和形貌和力学性能的影响,探讨Al、Ca添加及Al、Ca共同添加对Mg-Al-Ca-Mn合金组织和力学性能的影响。通过本课题的研究得出以下结果:①在MA系合金中,其Al含量添加只能少量提高再结晶组织含量,无法显著细化晶粒组织,因而其也不能有效提高挤压棒材的屈服强度,但Al添加可以改善压缩变形过程中应变硬化,显著提高抗压强度,Al含量从0.5%增加到1%未影响挤压棒材的塑性。在MX系合金中,添加Ca元素可以显著提高挤压棒材中动态再结晶组织的含量。随着Ca含量的增加,合金的屈服强度大幅提高,而抗压强度提高较少,塑性有一定的改善。②在MAX系合金中,当Ca含量由0.5%达到1%时可产生显著的强化,而Al的含量由0.5%增加到1%时,不能显著提高力学性能。然而Al元素的添加可以显著提高抗压强度。Al和Ca添加在0.5%-1%范围内对塑性影响较小。Al和Ca同时添加有助于挤压过程中动态再结晶,再结晶组织细小,挤压组织有较多的含Ca的沉淀相,Ca元素由0.5%增加到1%时,沉淀相含量显著增加。③平椭圆管平板部分和圆弧部分均具有很强的再结晶织构,但织构分布显著不同,圆弧部分均更容易形成带状交替分布的不同取向的组织,两个部位晶粒均比较细小,但平板部分切面和纵面组织均较圆弧部分更为细小,变形更均匀。Mg-Al-Ca-Mn热挤压平椭圆管沿挤压方向拉伸力学性能测试结果:屈服强度为255MPa,抗拉强度为278MPa,延伸率为5.1%。
[Abstract]:The research and development of heat resistant magnesium alloy has excellent performance and cheap, so that it can meet the application parts of automobile transmission system under high temperature conditions, has become an important issue to be solved, and the Mg-Al alloy containing Ca can adapt to this trend as well. Based on the MA10 (Mg, Mn, Al, MA11) (MX10, Mg, Mn, Ca, MX11), MAX101 (Mg, Mn, Al, Ca, MAX110, MAX111) seven kinds of hot extruded magnesium alloy bar and MAX (Mg-1.0t%Al-1.5wt%Ca-1.0wt%Mn) hot extrusion flat ellipse pipe as the object of study, through the observation of microstructure, mechanical performance analysis, alloy composition on precipitate composition system research, influence, distribution and morphology and mechanical properties of Al, Ca and Al added, Ca addition on Microstructure and mechanical properties of Mg-Al-Ca-Mn alloy. The following results through this study: 1 in the MA alloy, the Al content increased only a small amount of recrystallization The tissue content, not grain refining, so it can effectively improve the yield strength of the extruded bars, but the addition of Al can improve the compression deformation strain hardening process, significantly improve the compressive strength, the content of Al increased from 0.5% to 1% did not affect the plastic extrusion. In MX alloy, the addition of Ca element can significantly to improve the dynamic recrystallization microstructure of extruded bar content. With the increase of Ca content, the yield strength of the alloy increases, while the compressive strength increases slightly, the plastic has been improved. In MAX alloys, when the Ca content from 0.5% to 1% can produce significantly enhanced, and the content of Al by 0.5% increased to 1%, can significantly improve the mechanical properties. However, the addition of Al can significantly improve the compressive strength of.Al and Ca are added in the 0.5%-1% range of plastic was less affected by.Al and Ca addition contributes to the dynamic extrusion process Recrystallization and recrystallization microstructure, Ca containing more extrusion precipitates, Ca elements increased from 0.5% to 1%, precipitation phase content increased significantly. The flat part and the circular flat elliptical tube has strong recrystallization texture, but the texture distribution was significantly different, are more likely to form part of the arc with alternating distribution of different orientation, two parts of grain are relatively small, but the flat part section and vertical organization than the arc part is more finer, more uniform deformation.Mg-Al-Ca-Mn hot extruding flat elliptical tube along the extrusion direction tensile test results: yield strength 255MPa, tensile strength 278MPa, elongation 5.1%.

【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG379;TG146.22

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