挤压比对AZ31B镁合金组织和室温力学性能的影响  

Impact of extrusion ratio on microstructure and indoor temperature mechanical properties of AZ31B Magnesium alloy

作　　者：刘运腾[1] 林涛[1] 周吉学[1,2] 庄海华[1] 马百常 杨院生[3] 

机构地区：[1]山东省轻质高强金属材料重点实验室(筹),山东省科学院新材料研究所,山东济南250014 [2]山东省汽车轻量化镁合金材料工程技术研究中心,山东省科学院新材料研究所,山东济南250014 [3]中国科学院金属研究所,辽宁沈阳110016

出　　处：《山东科学》2016年第3期23-27,共5页Shandong Science

基　　金：山东省自然科学基金(ZR2015EQ019);山东省科学院青年基金(2016QN014)

摘　　要：研究了不同挤压比对AZ31B镁合金显微组织、力学性能的影响。采用光学显微镜观察了挤压棒材显微组织,通过材料万能试验测试了拉伸和压缩性能,并配合扫描电镜观察了拉伸试样的断口处显微组织和形貌。结果表明,随着挤压比的增加,组织由部分动态再结晶向完全动态再结晶过渡;合金拉伸断口由混合断裂转变为明显韧性断裂,压缩断口由解理断裂转变为准解理断裂。大挤压比可以获得良好的综合性能和细致均匀的组织,抗拉强度为310 MPa,屈服强度为200 MPa,延伸率为14%,并且拉伸压缩不对称性得到缓解,有利于镁合金的二次塑性加工。We addressed the impact of extrusion ratio on microstructure and mechanical properties of AZ31B Magnesium alloy. We applied optical microscopy （OM） to the observation of its microstructure, examined its mechanical properties by indoor temperature tensile and compressive test, and observed its fracture morphologies by scanning electron microscopy （SEM）. Results show that its microstructure changes from partially dynamic recrystallization to completely dynamic recrystallization with the increase of extrusion ratio. Its tensile fracture varies from mixed fracture to obvious ductility fracture. Compressive fracture is converted from cleavage fracture to quasi-cleavage fracture. Through high extrusion ratio, we can obtain fine and homogeneous microstructure and good comprehensive mechanical properties, tensile strength of 310 MPa, yield strength of 200 MPa and elongation rate of 14%. Asymmetry of tensile and compressive strength is reduced, which is therefore benefit for secondary plastic machining of Magnesium alloy.

关 键 词：AZ31B镁合金 热挤压 显微组织 力学性能 挤压比 

分 类 号：TG146.2[一般工业技术—材料科学与工程]