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研究了不同工艺参数下TiAl/TC4异种材料电子束焊接接头组织和力学性能,分析了焊缝中Al元素含量对焊缝组织和接头力学性能的影响。对中焊时焊缝区主要以α-Ti3Al相和α-Ti相为主,还包含少量B2相和YAlx相。焊缝中TiAl母材熔化量约为1/3,TC4母材约为2/3,Al质量分数约为28%,较高的Al含量促使形成脆性α相,降低了接头局部位置的塑韧性。对中焊时接头抗拉强度普遍不高,断裂为典型的脆性穿晶及准解理断裂。当电子束向TC4合金一侧进行焊接时,焊缝中Al含量进一步降低,接头组织得到改善,可提高接头的力学性能,偏移量hs=0.2mm时接头最高抗拉强度为422.2MPa。
The microstructure and mechanical properties of TiAl / TC4 dissimilar materials by electron beam welding were studied. The effects of Al content in the weld on the microstructure and mechanical properties of the weld were analyzed. Weld seam welding zone mainly α-Ti3Al phase and α-Ti phase-based, also contains a small amount of B2 phase and YAlx phase. The melting amount of TiAl base metal in the weld is about 1/3, the base material of TC4 is about 2/3, the Al mass fraction is about 28%, the higher Al content promotes the formation of brittle alpha phase and reduces the plasticity and toughness of the joint . Tensile strength of welded joint is generally not high, the fracture is a typical brittle transgranular and quasi-cleavage fracture. When the electron beam welding to the side of TC4 alloy, the Al content in the weld is further reduced, the joint structure is improved, and the mechanical properties of the joint can be improved. When the offset hs = 0.2mm, the maximum tensile strength of the joint is 422.2MPa.