Liu Minghua, Li Miaomiao, Wang Along, Zhang Mengqi, Wang Wei, Wang Wenli
School of Metallurgical Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Materials (Basel). 2019 Aug 25;12(17):2722. doi: 10.3390/ma12172722.
Ultrasonic treatment (UST) was applied in the smelting process of Mg-3Y-3.5Sm-2Zn-0.6Zr (wt %) alloy and the microstructure as well as mechanical properties of the experimental alloy were investigated. Results showed that the effect of UST on grain refinement was obvious, and the distribution of the second phases along grain boundary became discontinuous. The width of the grain boundary precipitates decreased after UST. The contents of solute elements within grains increased, and the morphologies of Zr-rich compounds and Y-rich compounds both at grain boundaries and within grains changed after UST. The mechanical properties of the experimental alloy after UST were significantly improved. The ultimate tensile strength (UTS) was 265 MPa, the tensile yield strength (TYS) was 171 MPa, and the elongation (EL) was 11%. The mechanism of UST of the alloy can be attributed to the combined effects of cavitation-induced heterogeneous nucleation and melt convection induced by acoustic streaming, resulting in the refinement of grains and the grain boundary precipitates, which promoted the improvement of mechanical properties.
对Mg-3Y-3.5Sm-2Zn-0.6Zr（质量分数）合金的熔炼过程施加超声处理（UST），并研究了实验合金的微观结构和力学性能。结果表明，UST对细化晶粒的效果明显，且第二相沿晶界的分布变得不连续。超声处理后晶界析出物的宽度减小。晶粒内溶质元素的含量增加，超声处理后晶界和晶粒内富Zr化合物和富Y化合物的形态均发生变化。超声处理后实验合金的力学性能显著提高。其抗拉强度（UTS）为265MPa，屈服强度（TYS）为171MPa，伸长率（EL）为11%。合金超声处理的机制可归因于空化诱导的非均匀形核和声流诱导的熔体对流的综合作用，导致晶粒和晶界析出物细化，从而促进了力学性能的提高。
