铝钛异种合金电子束焊接接头缺陷分析

Defect analysis of aluminum-titanium dissimilar alloy electron beam welded joint

采用电子束焊接工艺对7075铝合金和TC4钛合金异种金属进行焊接,主要研究焊接缺陷的形貌特点、形成原因及控制措施。结果表明:在铝合金与钛合金异种金属电子束焊接头中出现气孔、裂纹、缩孔等缺陷,调整焊接工艺参数、改变束斑在异种母材上的相对能量分布可以消除气孔、裂纹等缺陷。同时延长焊缝金属冷却时间,使液态熔池及时补充凝固过程中产生的孔隙,利用表面焦点减小熔池体积,对焊缝内的缩孔有一定的改善。最佳焊接参数为:工作距离272 mm,电子束流18 mA,焊接速度20 mm/s,聚焦电流415 mA。试验为提高铝合金与钛合金异种金属电子束焊接接头质量提供了参考。

The electron beam welding process was used to weld the dissimilar metals of 7075 aluminum alloy and TC4 titanium alloy.The morphological characteristics,formation reasons and control measures of welding defects were studied.The results show that defects such as pores,cracks and shrinkage cavities occur in the electron beam welding head of dissimilar metals in aluminum alloy and titanium alloy.Adjusting the welding process parameters and changing the relative energy distribution of the beam spot on the dissimilar base material can eliminate defects such as pores and cracks.At the same time,the metal cooling time of the weld metal is prolonged,so that the liquid molten pool can replenish the pores generated during the solidification process,and the surface focus is used to reduce the volume of the molten pool,and the shrinkage cavity in the weld seam is improved.The best welding parameters are:working distance 272 mm,electron beam current 18 mA,welding speed 20 mm/s,focusing current 415 mA.The test provides a reference for improving the quality of aluminum alloy titanium alloy dissimilar metal electron beam welded joints.