p相、αs相集束、αgb相典型的三態(tài)組織及點狀分布的殘留β相構(gòu)成，未見焊態(tài)焊縫中的α'馬氏體組織，使焊縫的強度-塑性-韌性得以兼顧；熱處理態(tài)焊接接頭強度降低但延伸率和室溫沖擊韌性增加；熱處理態(tài)焊接接頭拉伸斷口由大量撕裂唇包圍，韌窩深且均勻，呈微孔聚合韌性斷裂。焊態(tài)焊接接頭中焊縫區(qū)晶粒間的取向差大于15°的大角度晶界占比約83.78%；熱處理態(tài)焊接接頭焊縫中晶粒間的取向差大于15°的大角度晶界占比約為90.21%；通過XRD測試，發(fā)現(xiàn)焊態(tài)焊縫中主要由α'馬氏體組成，還有少量極弱的多角度α相衍射峰，而熱處理態(tài)焊縫中α相衍射峰中心角度位置與焊態(tài)焊縫中α'馬氏體一致，另外還發(fā)現(xiàn)了較為尖銳的β相（110）衍射峰。;Ti-6Al-4V titanium alloy plate was welded by a laser beam with self-developed titanium alloy flux-cored wire. The welded joint was solution treated at 920 °C for 1 h and aging treated at 650 °C for 2 h, and its microstructure and properties were compared with those of the as-welded joint. The results show that the heat-treated welded joint is composed of a typical tri-modal microstructure containing αp phase, αs phase colony, and αgb phase, as well as punctate distributed residue β phase. α' martensite microstructure in the as-welded joint is not found in the heat-treated joint, which makes the strength, plasticity, and toughness well balanced and maintained. The strength of the heat-treated welded joint is reduced, while elongation and impact toughness at room temperature are enhanced. The tensile fracture of the heat-treated welded joint is surrounded by massive shear lips. The dimples are deep and uniform, presenting as microvoid coalescence ductile fracture. In the as-welded joint, the proportion of large-angle grain boundaries with misorientation between grains in the weld zone greater than 15° accounts for 83.78%, and in the heat-treated welded joint, the proportion is about 90.21%. Through XRD test, it is discovered that the as-welded weld is mainly composed of α' martensite, with a small amount of extremely weak multi-angle α phase diffraction peak. In the heat-treated weld, the central angle position of α phase diffraction peak is consistent with that of α' martensite in the as-welded weld, with a sharp β phase (110) diffraction peak observed as well."/>