Gd对生物医用AZ31镁合金组织和性能的影响

Effect of Gd on microstructure and mechanical properties of biomedical AZ31 magnesium alloy

采用光学显微镜、扫描电镜、电子拉伸试验机等多种分析和测试手段,研究了稀土元素Gd对挤压态生物医用AZ31镁合金显微组织及室温下力学性能的影响.结果表明:在AZ31镁合金中添加质量分数为1.0%的Gd元素,合金平均晶粒尺寸由20μm减少至15μm,合金组织得到较明显细化;AZ31-1Gd镁合金的维氏硬度为56、抗拉强度为280 MPa、屈服强度为186 MPa,分别比AZ31镁合金提高了5.7%,3.7%和13.4%,且延伸率没有降低,表明Gd能较明显提高AZ31镁合金的力学性能;AZ31-1Gd合金的拉伸断裂具有韧性和脆性混合断裂的特征.

In the present work, the effects of Gd on microstructure and room-temperature mechanical properties of as-extrusion biomedical AZ31 magnesium alloy was investigated by optical microscopy and scanning electron microscopy, and measurements of tensile strength. The results show that the average grain size of the AZ31 magnesium alloy with the addition of 1.0 wt. % Gd was reduced from 20 μm to 15 μm compared with that of the AZ31 magnesium alloy. The Vickers hardness, the ultimate tensile strength and the yield strength of the AZ31-1Gd magnesium alloy are 56,280 MPa and 186 MPa, increasing by 5.7%,3.7% and 13.4% respectively. However, elongation of the AZ31-1Gd magnesium alloy did not reduce. It is indicated that the addition of 1.0wt. GGd can significantly improve the mechanical properties of AZ31 magnesium alloy. The tensile fracture surface for the AZ31-1Gd magnesium alloy revealed characteristics of toughness and brittle mixed fracture.