铒对AZ91镁合金铸态组织与力学性能的影响

Effect of Erbium Addition on Microstructure and Mechanical Properties of As-Cast AZ91 Magnesium Alloy

采用X射线衍射、金相观察、扫描电镜及拉伸性能测试,研究了Er的添加对AZ91镁合金的显微组织与力学性能影响。结果显示,基体合金中添加0.98%~1.92%Er后,显微组织主要由-αMg基体相、Mg17Al12相及Al3Er组成。添加Er能有效细化铸态合金的晶粒,使其平均晶粒尺寸从57μm降低到21μm;同时铒的添加改善了基体合金中Mg17Al12相的形态与分布,使AZ91镁合金的室温抗拉强度从162 MPa提高到211 MPa。

Effect of erbium addition on mierostrueture and mechanical properties of as-east AZ91 magnesium alloy was investigated using X-ray diffraction, Optical Microscopy, Scanning Electron Microscopy and Tensile Testing. It was shown that the based alloys containing 0.98% and 1.92% （mass fraction） Er were mainly com- posed of α-Mg matrix, Mg17M12 phase and Ml3Er phase.The erbium addition refined the grains of the as-east alloys, and the average grain size decreased from 57 μm to 21 μm. Moreover, the erbium addition improved the morphology and distribution of Mg17Al12 phase. Such improved microstructure was accompanied by the improvement of tensile strength from 162 MPa to 211 MPa with erbium addition at room temperature.