Zr含量对Mg-5Zn-2Al镁合金组织与性能的影响

采用光学显微镜及拉伸试验机等手段,研究了Zr含量对Mg-5Zn-2Al合金铸态和热处理后显微组织及力学性能的影响.结果表明,Zr的加入使Mg-5Zn-2Al镁合金的铸态和热处理后的晶粒得到明显的细化.在铸态及热处理条件下,合金的抗拉强度与伸长率均呈现先上升后下降的变化趋势.对于铸态合金而言,Zr含量为0.6%时,Mg-5Zn-2Al合金的晶粒最为细小,并且其抗拉强度与伸长率均达到最大值,为215 MPa和12.563%.经热处理后,合金的抗拉强度较铸态得到了显著地提高.当Zr含量为0.6%时,合金的抗拉强度达到最大,为249 MPa.

Effects of Zr Content on Microstructure and Mechanical Properties of Mg-A! Magnesium Alloy

Effects of Zr contents on microstructure and mechanical properties of as-cast and in heat treated Mg-5Zn-2AI magnesium alloy were investigated byOM (optical microscope) and tensile testing machine. The results verify that grain size in as-cast and in heat treated Mg-5Zn-2AI alloy can be remarkably refined with Zr addition. The tensile strength and elongation of the as-cast and heat treated alloy are firstly in-creased and then decreased. With 0. 6% Zr addition, the desirable grain size in the as-cast alloy can be ob-served, and the tensile strength and elongation reach 215MPa and 12. 563%, respectively. Compared with that of as-cast alloy, the tensile strength of the heat treated alloy is greatly improved with different Zr ad-ditions. With 0. 6% Zr addition, the tensile strength of the heat treated alloy reaches 249MPa.