Fine-grained Mg−1Mn−0.5Al−0.5Ca−0.5Zn alloy with high strength and good ductility fabricated by conventional extrusion  

常规热挤压制备高强韧细晶Mg−1Mn−0.5Al−0.5Ca−0.5Zn合金

作　　者：Guang-lin GU Xiang-nan KE Fa-ping HU Shu-jie ZHAO Guo-bin WEI Yan YANG Xiao-dong PENG Wei-dong XIE 顾光林;柯珦楠;胡发平;赵淑杰;魏国宾;杨艳;彭晓东;谢卫东(重庆大学材料科学与工程学院轻合金国际联合实验室,重庆400044;航空工业贵州安大航空锻造有限责任公司,安顺561005)

机构地区：[1]Joint International Laboratory for Light Alloys,College of Materials Science and Engineering,Chongqing University,Chongqing 400044,China [2]Guizhou Anda Aviation Forging Co.,Ltd.,Anshun 561005,China

出　　处：《Transactions of Nonferrous Metals Society of China》2022年第2期483-492,共10页中国有色金属学报（英文版）

基　　金：the financial supports from the Fundamental Research Funds for the Central Universities,China(Nos.2019CDCGCL316,2020CDJDPT001);Chongqing Research Program of Basic Research and Frontier Technology,China(No.cstc2019jcjy-msxmX0539)。

摘　　要：Mg−1Mn−0.5Al−0.5Ca−0.5Zn(wt.%)alloy was fabricated by conventional extrusion at 673 K with an extrusion ratio of 25:1,followed by aging at 473 K.The microstructure was characterized by scanning electron microscopy,electron back-scattered diffraction,and transmission electron microscopy.The mechanical properties were determined by the tensile test.The peak-aged sample shows fine recrystallized grains with an average grain size of 1.7μm.Area fraction of Al−Ca particles in the alloy increases significantly after peak aging.Meanwhile,botháañandác+añdislocations were observed to remain in the alloy after hot extrusion.Thus,the peak-aged sample exhibits simultaneously high strength and good ductility with the ultimate tensile stress,tensile yield stress,and tension fracture elongation of 320 MPa,314 MPa,and 19.0%,respectively.采用常规热挤压方法制备Mg−1Mn−0.5Al−0.5Ca−0.5Zn合金,挤压温度为673 K,挤压比为25:1,并进行473 K时效处理。采用扫描电镜、电子背散射衍射和透射电镜表征合金的显微组织,测试试样的温室拉伸性能。结果表明,经473 K、1 h峰值时效后,试样出现细小等轴晶,平均晶粒尺寸为1.7μm,Al−Ca颗粒面积分数明显增多。热挤压后仍能观察到áañ位错和ác+añ位错。峰值时效态样品表现出高强度和良好塑性,其抗拉强度为320 MPa,屈服强度为314 MPa,伸长率为19%。

关 键 词：Mg−Mn−Al−Ca−Zn alloy fine grain PRECIPITATE strength DUCTILITY 

分 类 号：TG146.22[一般工业技术—材料科学与工程]