A comparative study on the microstructure and properties of copper joint between MIG welding and laser-MIG hybrid welding. (15th November 2016)

• Record Type: Journal Article
• Authors: Zhang, Lin-Jie; Bai, Qing-Lin; Ning, Jie; Wang, An; Yang, Jian-Nan; Yin, Xian-Qing; Zhang, Jian-Xun
• Is Part Of: Materials & design. Volume 110(2016)
• Page Start: 35
• Page End: 50
• Publication Date: 2016-11-15
• Subjects: Copper -- Arc welding -- Laser-arc hybrid welding -- Microstructure -- Properties; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2016.07.117
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: Aiming to support the spread and application of laser-MIG hybrid (HYBRID) welding technology of pure copper in industry field, this work compared the microstructure, mechanical properties, thermal properties, and electric properties of 4 mm thick T2 copper joints between double-sided MIG (DMIG) welding and single-pass laser-MIG hybrid (HYBRID) welding. Compared with the DMIG welded joint, the HYBRID welded joint exhibited narrower heat-affected zone (HAZ), finer grains in fusion zone (FZ) and HAZ, and lower degree of softening. The tensile strengths of the HYBRID welded joint and the DMIG welded joint were 74% and 69% that of the base metal (BM). The tensile fracture of the HYBRID welded joint primarily consisted of dimples, while that of the DMIG welded joint consisted of both dimples and layered crack morphology. The HYBRID welded joint exhibited better electrical and thermal conductivities than the DMIG welded joint. The electrical conductivities of copper joints before and after annealing changed little, meanwhile impurity elements and micro-voids were found in the FZ of the welded joints. These results illustrated that impurity elements and micro-voids in the FZ should be primarily responsible for the decline of electrical conductivity. Graphical abstract: Highlights: Grain coarsening caused by annealing has little influence on the electrical conductivity of copper joints. The mechanical, electrical and thermal properties of hybrid welded joint are better than that of arc welded joint. The welding time consumed in hybrid welding process is only about 36% of that consumed in arc welding process. Hybrid welded copper joint has higher susceptibility to defects than arc welded copper joint.