Luo Chuanguang, Li Huan, Zhang Yuhui, Li Jianguo, Wen Yuanhua, Yang Lijun
Tianjin Key Laboratory of Advanced Joining Technology, Tianjin University, Tianjin 300072, China.
Sichuan Aerospace Changzheng Equipment Manufacturing Co., Ltd., Chengdu 610100, China.
Materials (Basel). 2020 Aug 27;13(17):3787. doi: 10.3390/ma13173787.
The weld joints of sprayed 2195-T6 and cast 2195-T8 aluminium-lithium alloy were created using tungsten inert gas with filler wire. The microstructures and mechanical properties of the weld joints were examined. The results of the microstructure analysis showed that the width of the equiaxed grain zone (EQZ) and the amount of the second phase θ'(AlCu) was greater in the weld joint of the cast 2195-T8 Al-Li alloy than that of the sprayed 2195-T6 Al-Li alloy. Tensile testing indicated that failures occurred in the EQZ and partially melted zone (PMZ) for both weld joints. The tensile strength and elongation of the weld joints of the sprayed 2195-T6 and cast 2195-T8 Al-Li alloys were about 68.2%, 89.7%, and 50.7% and 28.3% those of the base metal in the joint, respectively. The cast 2195-T8 Al-Li alloy joint had more pores and cracks, resulting in lower tensile strength and elongation than those in the sprayed alloy. Further, the tensile fracture surface morphology indicated that the fracture mode of the sprayed 2195-T6 Al-Li alloy was a mixed fracture mode dominated by plastic fracture and that of the cast 2195-T8 Al-Li alloy joints was a mixed fracture mode dominated by brittle fracture.
采用钨极惰性气体保护焊并添加填充焊丝的方法，制备了喷射态2195-T6和铸造态2195-T8铝锂合金的焊接接头。对接头的微观组织和力学性能进行了研究。微观组织分析结果表明，铸造态2195-T8铝锂合金焊接接头中等轴晶区（EQZ）的宽度和第二相θ'(AlCu)的数量，均大于喷射态2195-T6铝锂合金焊接接头。拉伸试验表明，两种焊接接头的失效均发生在等轴晶区和部分熔化区（PMZ）。喷射态2195-T6和铸造态2195-T8铝锂合金焊接接头的抗拉强度和伸长率，分别约为接头中母材的68.2%、89.7%、50.7%和28.3%。铸造态2195-T8铝锂合金接头中的气孔和裂纹较多，导致其抗拉强度和伸长率低于喷射态合金。此外，拉伸断口表面形貌表明，喷射态2195-T6铝锂合金的断裂模式是以塑性断裂为主的混合断裂模式，而铸造态2195-T8铝锂合金接头的断裂模式是以脆性断裂为主的混合断裂模式。
