低温退火协同调控Mg-Bi基合金的腐蚀和力学行为  

Synergistic tailoring corrosion and mechanical behaviors of Mg-Bi based alloy through low-temperature annealing

作　　者：魏招龙 张全福 宋蕾 曹继栓 王利飞[1] 余晖[4] 程伟丽[1,2] WEI Zhaolong;ZHANG Quanfu;SONG Lei;CAO Jishuan;WANG Lifei;YU Hui;CHENG Weili(School of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China;Shanxi Province Multi-functional Magnesium Alloy Forming Technology Innovation Center,Xiaoyi 032308,China;Xiaoyi Dongyi Magnesium Industry Co.,Ltd.,Xiaoyi 032308,China;School of Materials Science and Engineering,Hebei University of Technology,Tianjin 300132,China)

机构地区：[1]太原理工大学材料科学与工程学院,太原030024 [2]山西省多功能镁合金成型技术创新中心,孝义032308 [3]孝义市东义镁业有限公司,孝义032308 [4]河北工业大学材料科学与工程学院,天津300132

出　　处：《中国有色金属学报》2025年第3期745-757,共13页The Chinese Journal of Nonferrous Metals

基　　金：山西省自然科学基金资助项目(202103021224049);吕梁市校地合作重点研发专项(2023XDHZ09)。

摘　　要：本文研究了低温退火态Mg-0.8Bi-0.4Zn-0.4Ag-0.2Mn合金的微观组织特征、室温拉伸性能和腐蚀行为。结果表明:挤压态Mg-0.8Bi-0.4Zn-0.4Ag-0.2Mn合金经过(150℃,24 h)退火处理,该合金表现出典型的双尺寸晶粒组织,其相组成为α-Mg和少量的Mg_(3)Bi_(2)及α-Mn相。此外,该合金的屈服强度、抗拉强度和伸长率分别为267 MPa、299.7 MPa和16.1%,表现出良好的强度和塑性协同性。这主要是粗晶区的应力协调和细晶区的强化效用共同作用的结果。合金的腐蚀模式由浸泡早期阶段的点蚀转变为浸泡中期阶段的晶间腐蚀,在浸泡后期阶段转变为晶内腐蚀。这主要是由于基体的腐蚀次序为第二相毗邻基体→晶界→晶内。因此,低温退火是协同提升镁合金力学性能和耐腐蚀性能的有效手段。This paper investigated the microstructure,tensile properties at room temperature,and corrosion behaviors of extruded Mg-0.8Bi-0.4Zn-0.4Ag-0.2Mn alloy after low temperature annealing.The results indicate that the microstructure consisting of bimodal-structured grains can be obtained through low-temperature annealing at 150℃for 24 h.Furthermore,the investigated alloy exhibits an excellent strength-ductility synergy,with yield strength,ultimate tensile strength,and elongation values of 267 MPa,299.7 MPa,and 16.1%,respectively.This is ascribed to the synergistic effect between fine and coarse grains.With increasing immersion time,the dominant corrosion mechanism of the studied alloy transforms from pitting corrosion at early stage to intergranular corrosion at intermediate stage,and then to intracrystalline corrosion at the later stage.This phenomenon is primarily attributed to the corrosion order of the Mg matrix:Mg matrix neighboring the second phase→grain boundaries→grain interior.Therefore,low temperature annealing is an effective strategy to improve the mechanical properties and corrosion resistance of magnesium alloys.

关 键 词：镁合金 低温退火 双尺寸组织 力学性能 腐蚀行为 

分 类 号：TG146.22[一般工业技术—材料科学与工程]