The effects of different Y contents （0, 0. 94wt%, 0. 267wt% and 4. 61wt%） on the microstructure and meehainieal 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, MgTZn3 and Mg3Y2Zns, and when the content of Y element was 2. 67wt%, the phases was a-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.%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Mg3Y2Zn。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250．4，125．3MPa，伸长率为12．73%。
展开▼
