差温挤压工艺对Mg96.32Gd2.5Zn1Zr0.18合金显微组织和力学性能的影响  

Effects of Differential Temperature Extrusion Process on Microstructures and Mechanical Properties of Mg96.32Gd2.5Zn1Zr0.18 Alloy

作　　者：程晓伟 吴玉娟[1] 容伟 彭立明[1,2] 丁文江[1] CHENG Xiaowen1, WU Yujuan1, RONG Wei1, PENG Liming1,2, DING Wenjiang1(1. School of Materials Science and Engineering, National Engineering Research Center for Precision Molding of Light Alloy and State Key Laboratory of Metal Matrix Composite Materials, Shanghai Jiao Tong University, Shanghai 200240, China; 2. Shanghai Light Alloy Precision Forming National Engineering Research Center Co., Ltd., Shanghai 200000, Chin)

机构地区：[1]上海交通大学材料科学与工程学院,轻合金精密成型国家工程研究中心和金属基复合材料国家重点实验室,上海200240 [2]上海轻合金精密成型国家工程研究中心有限公司,上海200000

出　　处：《热加工工艺》2018年第5期42-45,共4页Hot Working Technology

基　　金：国家重点研发计划项目(2016YFB0701201);国家自然科学基金项目(51304135,51401125);上海交通大学“SMC-晨星青年学者奖励计划”;上海市优秀技术带头人计划项目(14XD1425000);江苏省科技成果转化资助项目(BA2016039)

摘　　要：通过OM、SEM显微组织分析以及室温拉伸测试研究了不同热挤压模具温度（320～420℃）对差温挤压的半连续铸造Mg_（96.32）Gd_（2.5）Zn_1Zr_（0.18）合金显微组织及力学性能的影响。结果表明：热挤压后合金发生回复和动态再结晶,具有双峰组织特征。随着模具温度升高,再结晶程度增加,双峰组织特征降低,晶粒尺寸增加,长周期堆垛有序结构数量减少。模具温度为320℃的挤压态合金达到最佳的力学性能：抗拉强度418 MPa,屈服强度383 MPa,伸长率7.1%。The effect of on different die temperatures （320-420℃） microstructure and mechanical properties of semi- continuous casting Mg96.32Gd2.5Zn1Zr0.18 alloy after differential temperature extrusion were investigated by OM, SEM analyses and tensile test. The results show that recovery and dynamic recrystallization in the alloy occur after hot extrusion ,which has microstructure characteristics with two-peaks. With the increase of the die temperature, the recrystallization degree and grain size increase, and the quantity of long period stacking order （LPSO） structure and microstructure characteristics with two-peaks decrease. The extruded alloy at die temperature of 320℃ achieves the best mechanical properties： tensile strength of 418 MPa, yield strength of 383 MPa and elongation of 7.1%.

关 键 词：差温挤压 Mg-Gd-Zn-Zr合金 LPSO结构 显微组织 力学性能 

分 类 号：TG379[金属学及工艺—金属压力加工]