热处理对含微量镧AZ91镁合金组织和性能的影响  

Effect of Heat-Treatment on Microstructure and Properties of AZ91 Magnesium Alloy with Trace La

作　　者：祁小叶[1] 张金玲[1,2] 刘璐[1] 王社斌[1,2] 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：《机械工程材料》2012年第3期35-38,共4页Materials For Mechanical Engineering

基　　金：山西省回国留学人员科研项目(2008-39)

摘　　要：用XRD、SEM、EDS和显微硬度仪等研究了固溶、时效处理对真空精炼的含0.164 8%(质量分数)镧AZ91镁合金显微组织和力学性能的影响。结果表明:加入微量镧后的AZ91镁合金在410℃×24h空冷固溶+170℃×30h空冷时效后,第二类β相大量析出,且呈不连续层片状沿晶界两侧分布;时效态含镧AZ91镁合金的抗拉强度、屈服强度、伸长率和显微硬度分别比铸态不含镧AZ91合金的提高了41.84%,65.08%,35.65%和47.62%;其原因是微量镧改变了热处理中铝原子的扩散状态,有效控制了第一、二类β-Mg17Al12相析出时的形态与分布。The influences of solution and aging treatments on microstructure and mechanical properties of AZ91 magnesium alloy with 0.164 8wt% La refined by vaccum process were studied by X-ray diffraction,scanning electron microscopy,energy dispersive spectroscopy,microhardness testing and so on.The results show that a great number of second β phases after solid（410 ℃×24 h air cooling） and aging treatments（170 ℃×30 h air cooling）.Compared with cast magnesium alloy,the tensile strength,yield strength,elongation and hardness of aged AZ91 magnesium alloy with La increased by 41.84%,65.08%,35.65%,47.62%,respectively.The reason was that the diffusion state of Al atoms was changed by trace La during heat treatment,and thus the morphology and distribution of first and second β-Mg17Al12 phases were controlled effectively.

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]