流变轧制AZ91合金的热处理和组织性能调控  

Tailoring the Microstructure and Mechanical Properties of AZ91 Alloy by Rheo-rolling and Heat Treatment

作　　者：管仁国 王祥 铁镝 任浩博 王宇翔 刘海峰 颜路飞 陈民芳[3] Guan Renguo;Wang Xiang;Tie Di;Ren Haobo;Wang Yuxiang;Liu Haifeng;Yan Lufei;Chen Minfang(Key Laboratory of Lightweight Structural Materials Liaoning Province,School of Materials Science and Engineering,Northeastern University,Shenyang 110819,China;The CITIC Dicastal Institute,Qinhuangdao 066011,China;School of Materials Science and Engineering,Tianjin University of Technology,Tianjin 300384,China)

机构地区：[1]东北大学材料科学与工程学院辽宁省轻量化用关键金属结构材料重点实验室,辽宁沈阳110819 [2]中信戴卡研究院,河北秦皇岛066011 [3]天津理工大学材料科学与工程学院,天津300384

出　　处：《稀有金属材料与工程》2020年第11期3718-3723,共6页Rare Metal Materials and Engineering

基　　金：National Natural Science Foundation of China(51771045,U1764254,51974083);Department of Science&Technology of Liaoning Province(XLYC1802128)。

摘　　要：对连续流变轧制AZ91合金在热处理过程中的组织和力学性能演化进行了研究。热处理后2种析出相在基体中出现:一种是晶界处的非连续析出相,另一种是从过饱和基体中析出的小尺寸连续析出相。随着时效温度的升高,原子扩散速度也随之提高,导致更多的析出相生成和长大。合金的维氏硬度和拉伸强度峰值在16h时效后出现,而合金的延伸率随着时效时间的延长和时效温度的提高呈下降趋势。经过对实验结果的分析,适合提升合金综合力学性能的热处理制度为415℃固溶20 h加220℃时效16 h。经热处理后得到的维氏硬度、拉伸强度和延伸率分别为990MPa,251MPa和4.5%,各项性能均显著优于流变轧制态合金。相对于传统成型手段,流变轧制加热处理方法成型的AZ91合金展现了优异且均衡的综合力学性能。The evolution of microstructure and mechanical properties of the continuous rheo-rolled AZ91 magnesium alloy during heat treatment was revealed.Two kinds of Mg17Al12 phases precipitated from the supersaturated magnesium matrix were observed:most of them distributed discretely at grain boundary while the rest precipitated in alloy matrix in small size.With higher aging temperature,atom diffusion velocity increased and more precipitates formed.As a result,the hardness and the tensile strength peaked at 16 h,whilst the elongation decreased with the increase of time and temperature.The optimal comprehensive mechanical properties were obtained after solution treatment at 415℃for 20 h and aging tre atment at 220℃for 16 h.The tailored hardness(HV),tensile strength and elongation of the rheo-rolled alloy after heat treatment reach 990 MPa,251 MPa and 4.5%,respectively,which are significantly higher than those of the untreated alloy.Compared with traditional processing methods,rheo-rolling followed by heat treatment demonstrates its effectiveness on tailoring and obtaining balanced mechanical properties of AZ91 alloy.

关 键 词：AZ91合金 流变轧制 热处理 微观组织 力学性能 

分 类 号：TG335[金属学及工艺—金属压力加工] TG146.22[一般工业技术—材料科学与工程]