铝含量对TiAl/TC4电子束焊接接头组织及性能影响(英文)

Influence of Aluminum Content on the Microstructure and Properties of Electron Beam Welded Joints of TiAl/TC4 Alloy

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。

Electron beam welding experiments of TiAl and TC4 titanium alloy under different welding parameters were carried out.The influence of aluminum content in the weld on the microstructure and mechanical properties of the joints were analyzed.The weld mainly consisted of the α-Ti 3 Al phase and α-Ti phase,with a small quantity of B2 phase and YAl x phase when the beam acted on the contact face.In the joints the content of molten TiAl and TC4 was about 1/3 and 2/3,and the percentage of Al was about 28 wt%.This high content of Al led to the formation of a brittle α phase,thus the ductility and toughness of the joints decreasing.In the centered beam welding,the tensile strength of the joints was low.The fracture of the joints was the classic brittle transgranular and quasi-cleavage fracture.When the beam was deflected towards the TC4 alloy,the Al content in the weld decreased and the mechanical properties of the joints improved.When the lateral deviation h s was 0.2 mm,the highest tensile strength of the joints reached 422.2 MPa.