时效处理和La含量对AZ91合金组织和力学性能的影响  

EFFECT OF AGING TREATMENT AND La CONTENT ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF AZ91 ALLOY

作　　者：王社斌[1,2] 祁小叶[1] 张金玲[1,2] 刘璐[1] 许并社[1,2] 

机构地区：[1]太原理工大学材料科学与工程学院,太原030024 [2]太原理工大学教育部新材料界面与工程重点实验室,太原030024

出　　处：《金属学报》2011年第6期743-750,共8页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目50901048;山西省回国留学人员科研项目2008-39资助~~

摘　　要：借助XRD,SEM,EDS和显微硬度仪等分析测试手段,研究了时效处理和La含量对真空精炼的AZ91合金显微组织和力学性能的影响.结果表明:时效处理可以使第二类β相大量析出,且β相呈不连续层片状沿晶界两侧分布.随La含量的增加,β相的尺寸逐渐减小,而α相的尺寸则呈现先减小后增加的趋势.铸态和时效态试样的力学性能参数均随La含量的增加呈现出先增加后减小的趋势.时效态试样的抗拉强度、屈服强度、延伸率和Vickers硬度分别比铸态试样提高12.65%,16.85%,13.71%和37.24%.当La含量达到0.1648%时,抗拉强度、屈服强度、延伸率和Vickers硬度分别达到276 MPa,208 MPa,13.85%和132HV.The effects of aging treatment and La content on the microstructures and mechanical properties of AZ91 magnesium alloys were investigated by XRD, SEM, EDS and microhardness meter. The results showed that a great number of β-phases were precipitated and distributed along the grain boundaries after aging treatment. As the content of La increased, the grain size of β-phase decreased gradually, while a-phase decreased first and then increased. The mechanical properties of as cast and aged specimens increased first and then decreased as the content of La increased. The tensile strength, yield strength, elongation and Vickers hardness of aged magnesium alloys were increased by 12.65%, 16.85%, 13.71% and 37.24%, respectively. When the content of La was 0.1648%, the tensile strength, yield strength, elongation and Vickers hardness achieved 276 MPa, 208 MPa, 13.85% and 132 HV, rest）ectivelv.

关 键 词：AZ91镁合金 时效 力学性能 显微组织 

分 类 号：TG166.4[金属学及工艺—热处理]