摘要
采用XRD、SEM、EDS和拉伸试验,研究添加Zn元素前后铸态和等通道转角挤压(ECAP)态Mg15Al高铝镁合金的组织和力学性能。结果表明,Zn添加到Mg15Al合金中,主要固溶于β-Mg17Al12相,不生成新相。能够促进铸态Mg15Al合金中α-Mg晶粒细化,使β-Mg17Al12相质量分数增加,以及网状化加剧;使ECAP挤压后Mg15Al-1Zn合金中α-Mg基体晶粒平均尺寸由ECAP态Mg15Al合金的11.3μm减少到8.73μm,促进了β-Mg17Al12相的碎化和均匀分布;ECAP挤压能显著提高Mg15Al-1Zn和Mg15Al合金的综合力学性能,ECAP态Mg15Al-1Zn合金的抗拉强度较铸态合金提高了86%,ECAP态Mg15Al合金抗拉强度较铸态提高了60%,而且在屈服强度和塑性变化不大的情况下,ECAP态Mg15Al-1Zn合金比ECAP态Mg15Al合金室温抗拉强度提高了61.8MPa。说明Zn元素添加,能促进ECAP挤压对Mg15Al合金的晶粒细化效果,提高合金的综合力学性能。
Microstructures and mechanical properties of the as-cast and equal channel angular pressed （ECAPed） Mgl5A1 alloy and Mg15A1 1Zn alloy were investigated by OM, XRD, SEM, EDS and the tensile tests in this paper. The results show that Zn element added to Mgl5A1 alloy mainly dissolved into the β-Mg17 Al12 phase and no new phase presented. The grain size of the as- cast Mgl5A1 alloy was decreased with addition of lwt1 Zn element, meanwhile, net-work β-Mg17 Al12 phases tend to form with the increasing amount of β-MglTAl12. After processing by ECAP, the grain size of a-Mg matrix was decreased sharply, from 11.3/xm （in Mgl5A1） to 8.73μm （in Mg15Al-1Zn） and the net structure of 13-Mg17 All2 phase was disappeared and the morphology was modified. As a result, the mechanical properties of Mgl5AI-IZn and Mgl5A1 alloy were improved by ECAP, and the tensile strength of MglSAl-lZn alloy and MglSA1 alloy was increased by 86% and 60% respectively compared with its as-cast state. Moreover, the increased amount of ECAPed Mg15Al-AlZn alloy was greater than that of ECAPed Mg15A1, about 61.8MPa in room temperature tensile strength under the condition of the yield strength and elongation changing little. It＇s significant to notice that the grain refinement and 13 phase fragmentation during ECAP processing was strongly promoted and the mechanical properties of the alloy was further improved by the action of Zn addition.
出处
《塑性工程学报》
CAS
CSCD
北大核心
2013年第4期59-65,共7页
Journal of Plasticity Engineering
基金
国家自然科学基金资助项目(51175363)
2013山西省高等学校科技创新项目资助
山西省自然科学基金资助项目(2010011033-1)
关键词
高铝镁合金
Zn元素
等通道转角挤压
微观组织
力学性能
high-Al magnesium alloys
Zinc
equal channel angular pressing （ECAP）
microstructure
mechanical properties
