Effects of extrusion and heat treatments on microstructure and mechanical properties of Mg-8Zn-1Al-0.5Cu-0.5Mn alloy  

挤压和热处理对Mg-8Zn-1Al-0.5Cu-0.5Mn镁合金显微组织和力学性能的影响（英文）

作　　者：朱绍珍 罗天骄[1] 张廷安[3] 刘运腾 杨院生[1] 

机构地区：[1]中国科学院金属研究所,沈阳110016 [2]东北大学材料科学与工程学院,沈阳110819 [3]东北大学多金属共生矿生态化冶金教育部重点实验室,沈阳110819 [4]山东省轻质高强金属材料省级重点实验室,济南250014

出　　处：《Transactions of Nonferrous Metals Society of China》2017年第1期73-81,共9页中国有色金属学报（英文版）

基　　金：Project(2013CB632205)supported by the National Basic Research Program of China;Project(51274184)supported by the National Natural Science Foundation of China

摘　　要：The effects of extrusion and heat treatments on the microstructure and mechanical properties of Mg-8Zn-1Al-0.5Cu- 0.5Mn magnesium alloy were investigated. Bimodal microstructure is formed in this alloy when it is extruded at 230 and 260 ℃, and complete DRX occurs at the extruding temperature of 290 ℃. The basal texture of as-extruded alloys is reduced gradually with increasing extrusion temperature due to the larger volume fraction of reerystallized structure at higher temperatures. For the alloy extruded at 290 ℃, four different heat treatments routes were investigated. After solution ＋ aging treatments, the grains sizes become larger. Finer and far more densely dispersed precipitates are found in the alloy with solution ＋ double-aging treatments compared with alloy with solution ＋ single-aging treatment. Tensile properties are enhanced remarkably by solution ＋ double-aging treatment with the yield strength, tensile strength and elongation being 298 MPa, 348 MPa and 18%, respectively. This is attributed to the combined effects of fine dynamically reerystallized grains and the uniformly distributed finer precipitates.研究挤压和热处理对Mg-8Zn-1Al-0.5Cu-0.5Mn镁合金显微组织和力学性能的影响。结果表明,合金在230和260°C挤压时呈现双峰组织,而在290°C挤压时合金发生了完全的动态再结晶。随着挤压温度的升高,合金动态再结晶越充分,从而使其基面织构降低。通过研究4种不同的热处理制度对290°C下挤压成型合金的影响发现,经过固溶+时效处理后,合金的晶粒发生明显长大。与固溶+单级时效的合金相比,固溶+双级的工艺能显著细化析出相,提高析出相的密度。同时,经固溶+双级时效处理后合金的力学性显著提高,其屈服强度、抗拉强度和伸长率分别为298 MPa、348 MPa和18%,这主要是由细小的再结晶晶粒与均匀弥散分布的第二相共同作用的结果。

关 键 词：magnesium alloy extrusion microstructure TEXTURE heat treatment mechanical properties 

分 类 号：TG146.22[一般工业技术—材料科学与工程] TG379[金属学及工艺—金属材料] TG166.4[金属学及工艺—金属学]