Influence of filler materials on microstructure and mechanical proper-ties of MGH956 alloy in TIG welding

摘要

In order to improve the mechanical properties of MGH956 alloy fusion welding joint, two kind of self-made materials were used as filler materials to MGH956 for TIG welding respectively. Microstructure, reinforced particles and room temperature tensile strength of joints were researched by testing method such as scanning electron microscope(SEM), X-ray diffraction(XRD) and energy dispersive X-ray spectrometry(EDS). And compared to joint which fill base material. The results show that new reinforced phases such as TiC, TiN, Ni3Al and AlNi are produced in weld zone with two kind of self-made materials as filler materials in the process of welding. These reinforcements size is about 1um, and the distribution of particles is very uniform in matrix. The number of pores and agglomerate Al-Y-O composite oxides is corresponding decreased compared to joint which fill base material. Thus, weld joint performance is enhanced. The average room temperature tensile strength of joints are 581MPa and 607MPa respectively. The fracture of joints both in general exhibit brittle fracture.