【摘要】 针对2060/2099铝锂合金机身壁板T型接头双侧激光同步焊接组织的改善及力学性能的提高,采用焊缝合金化手段对焊缝组织进行合金调控,研究了合金元素对焊缝热裂纹敏感性及力学性能的影响。结果表明,2060/2099铝锂合金双侧激光同步焊接组织内存在特殊的等轴细晶区,为接头薄弱区域;焊缝晶界主要由AlLiSi和Al₆CuLi₃两种晶间相及Al-Cu,Al-Si共晶组织构成;采用Al-Si-Cu系新焊丝CW3能够促进Al₆CuLi₃相及二次枝晶的形成,有效提高晶界强度并抑制热裂纹的产生,等轴细晶区内显微硬度水平的提高使T型接头的综合力学性能得到明显改善,其纵向抗压载荷提高为92.7 kN,横向抗拉强度提高为412 MPa,达到母材抗拉强度的80%以上。更多还原

【Abstract】 To improve the microstructures and mechanical properties of double-sided laser beam welded Al-Li alloys 2060/2099 T-joints,alloying method has been applied to fulfill elements regulation within the weld,and the influences of elements on hot cracking susceptibility and mechanical properties have been studied. The results show that a special region of non-dendritic equiaxed zone（ EQZ） has been found within the weld of double-sided laser beam welded Al-Li alloys 2060/2099. EQZ is the weak area of the weld. Weld boundaries are mainly composed of Al Li Si,Al₆CuLi₃ and Al-Cu/Al-Si eutectics. By using the new Al-Si-Cu CW3 wire,formations of Al₆CuLi₃ phases and secondary dendrites have been promoted,and grain boundary strength and hot cracking inhibition have been improved. By the increase of microhardness in EQZ,the combined mechanical properties of T-joints have been increased apparently. The compressive load increased to 92. 7 kN,the tensile strength increased to 412 MPa,reached more than 80% of the base metal.更多还原