Through adding rare earth(RE) yttrium oxide (Y2O3 , 0% , 2% ,4% , and 6% ,mass fraction) to the self-contained filler material, TIG was adopted to make the thickness of 1. 3mm MGH956 alloy in-situ alloying welding. The effects of different contents of Y2O3 on microstructure and mechanical properties of the welding seam metal were investigated. The results show that the microstructure of the welding seam with Y2 O3 was main equiaxed grain, the grains are fine and uniform, without apparent metal oxide clusters and with the new reinforced particles precipitation. That filling Y2O3 in the welding process can refine the grain size and also improve the hardness and tensile strength of the weld-joints, wherein, the weld joint tensile strength of the filler material containing 4% Y2O3 are better than those with 2% and 6% Y2O3 ( mass fraction) , the average value is 605 MPa, reaching 84% tensile strength of the parent material.%采用TIG焊对1.3mm厚的MGH956合金进行原位合金化焊接,对比研究了未添加,添加质量分数为2％,4％和6％的Y2O3对焊缝显微组织及力学性能的影响.结果表明:添加Y2O3后的焊缝组织以等轴晶为主,焊缝晶粒细小均匀,没有明显的金属氧化物聚集现象,并且有新的增强相颗粒析出.Y2O3的添加不仅细化了晶粒,还提高了接头的显微硬度和抗拉强度,从而改善了焊接接头的力学性能.Y2O3添加量为4％时接头抗拉强度最高,平均抗拉强度为605MPa,达到母材的84％.
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