钇含量对铸态镁锌锆合金组织及力学性能的影响

Effect of Y Contents on Microstructure and Mechanical Properties for as-Cast Mg-Zn-Zr Alloy

摘要: 研究了不同钇含量(质量分数为0, 0.94%, 2.67%, 4.61%)对铸态Mg-6Zn-0.7Zr合金显微组织及力学性能的影响。结果表明: 钇元素主要富集在晶界; 晶界析出相呈鱼骨状和块状, 并逐渐连续成网状; 当钇的质量分数为0.94%时, 合金主要为α-Mg、Mg7Zn3和Mg3Y2Zn3相; 当钇的质量分数为2.67%时, 析出相为α-Mg、Mg12YZn和Mg3Y2Zn3相; 随着钇含量的增多, 合金的抗拉强度、屈服强度和伸长率先增大后减小, 当钇的质量分数为2.67%时, 合金的性能最佳, 抗拉强度和屈服强度分别为250.4, 125.3 MPa, 伸长率为12.73%。

Abstract: The effects of different Y contents (0, 0.94wt%, 0.267wt% and 4.61wt%) on the microstructure and mechainical properties of the as-cast Mg-6Zn-0.7Zr were studied. The results show that Y elements was rich in grain boundaries. The precipitation phases appeared in fishbone-like and block, and continuously distributed along grain bondaries in network form. When the content of Y element was 0.94wt%, the phases was α-Mg, Mg7Zn3 and Mg3Y2Zn3, and when the content of Y element was 2.67wt%, the phases was α-Mg, Mg12YZn and Mg3Y2Zn3. The tensile strength, yield strength and elongation increased firstly and then decreased with the increase of Y contents. The properties of the alloy was best when the content of Y element was 2.67wt%, and the tensile strength, yield strength and elongation was 250.4, 125.3 MPa and 12.73%, respectively.