摘要
通过在Mg-Zn-Al系合金中添加不同质量分数的Ca元素,制备Mg-5Zn-2Al-xCa(ZA52-xCa)合金(x=0,0.5,1,1.5),使用光学显微镜(OM)、X射线衍射分析(XRD)、扫描电镜(SEM)研究了Ca元素对ZA52合金显微组织和力学性能的影响。结果表明,Ca含量在质量分数为1%内时对合金组织有明显的细化和强化作用;添加质量分数为0.5%Ca时,合金抗拉强度和断后伸长率最佳,分别达到了214 MPa和12%。Ca元素的加入促使ZA52合金中形成第二相Mg_(32)(Al,Zn)_(49)和Mg_(2)Ca,有效细化了组织,并提升了合金的强度和塑性。随Ca元素含量的增加,合金中析出的第二相数量也随之增加,但过多的第二相对合金性能不利,且ZA52-xCa合金的拉伸断裂方式由韧脆混合断裂向脆性断裂转变。
Mg-5Zn-2Al-xCa(ZA52-xCa)alloy(x=0,0.5,1,1.5)was prepared by adding Ca element with different mass fraction into Mg-Zn-Al alloy.The effects of Ca addition on the microstructure and mechanical properties of ZA52 alloy were investigated by OM,XRD and SEM.The results show that Ca content within the mass fraction of 1%has obvious refinement and reinforcement on the microstructure.The tensile strength and elongation after fracture reach the best combination of 214 MPa and 12%when the Ca addition is 0.5%.Ca element prompts the formation of the second phase Mg(Al,Zn)and Mg_(2)Ca,which can effectively refine the microstructure and improve the strength and plasticity of the alloy.The precipitation of second phase becomes more numerous with the increase of the Ca addition.However,too much second phase is unfavorable to the property of the alloy and the tensile fracture mode of ZA52-xCa alloy changes from ductile and brittle mixed fracture to brittle fracture.
作者
李明哲
韩富银
张长江
张树志
史群
LI Mingzhe;HAN Fuyin;ZHANG Changjiang;ZHANG Shuzhi;SHI Qun(College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China)
出处
《热加工工艺》
北大核心
2022年第18期34-38,共5页
Hot Working Technology
基金
山西省重点研发计划项目(201903D421084,201903D121056)
山西省重大科技专项项目(20191102007)。
