挤锻复合成形汽车高强镁合金的组织与性能  

Microstructure and properties of automotive high-strength magnesium alloy by extrusion-forging compound forming

作　　者：武卫民 孙晨宇 Wu Weimin;Sun Chenyu(School of Automotive Engineering,Shanxi Vocational University of Engineering Science and Technology,Jinzhong 030600,China;College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]山西工程科技职业大学汽车工程学院,山西晋中030600 [2]太原理工大学材料科学与工程学院,山西太原030024

出　　处：《锻压技术》2022年第12期27-30,共4页Forging & Stamping Technology

基　　金：国家自然科学基金资助项目(51308396);山西省高等学校教学改革创新项目(J2020440)。

摘　　要：为了研究挤锻复合成形汽车高强镁合金的显微组织和力学性能,采用挤锻复合成形方法制备了Mg-6Al-4Sn汽车用高强镁合金试样,并采用金相和扫描电镜方法进行了试样的显微组织分析,以及室温条件下试样的力学性能测试和拉伸断口扫描电镜分析。结果表明:挤锻复合成形可以获得组织细小、力学性能优良的Mg-6Al-4Sn汽车用高强镁合金,合金内部晶粒细小、组织分布均匀性较好、平均晶粒尺寸约为6.2μm,基体上分布有类似球形的大颗粒状Mg_(17)Al_(12)相和呈弥散分布的细小颗粒状Mg2 Sn相。挤锻复合成形Mg-6Al-4Sn汽车用高强镁合金的抗拉强度为312 MPa、屈服强度为268 MPa、断后伸长率为15.6%,拉伸断口呈现韧窝状花样,同时伴随着均匀分布的撕裂棱,表现为较为明显的韧性断裂特点。In order to study the microstructure and mechanical properties of automotive high-strength magnesium alloy by extrusion-forging compound forming,Mg-6Al-4Sn high-strength magnesium alloy specimens for automotive were prepared by extrusion-forging compound forming method,and the microstructure of specimen was analyzed by metallography and SEM.Then,the mechanical properties of specimen were tested at room temperature,and the tensile fracture of specimen was analyzed by SEM.The results show that Mg-6Al-4Sn automotive high-strength magnesium alloy with fine microstructure and good mechanical properties can be obtained by extrusion-forging compound forming,the internal grains of alloy are fine,the structure distribution is relatively uniform,the average grain size is about 6.2μm,and there are spherical large granular Mg_(17)Al_(12) phase and dispersed fine granular Mg2 Sn phase on the matrix.The tensile strength of Mg-6Al-4Sn automotive high-strength magnesium alloy by extrusion-forging compound forming is 312 MPa,the yield strength is 268 MPa,the elongation after fracture is 15.6%,and the tensile fracture presents a dimple-like pattern,accompanied by evenly distributed tear edges,which shows obvious ductile fracture characteristics.

关 键 词：汽车材料 Mg-6Al-4Sn镁合金 挤锻复合成形 显微组织 力学性能 

分 类 号：TG379[金属学及工艺—金属压力加工] TG319