Study On Microstrure And Properties Of T2 Copper/1060 Aluminum Laser Welding

Copper and aluminum pure copper due to high conductivity,low weight and good corrosion resistance and other properties,today is used in various industries in society,but because the physical and chemical properties between copper and aluminum materials are very large,so the two welding is more difficult.At present,the polar ear material of lithium batteries is mainly welded by copper and aluminum alloys,and after investigation and comparison,the traditional lithium battery polar ears mostly use brazing methods,but due to the characteristics of aluminum and copper,the performance of the polar ears obtained is poor.The flexibility of the laser welding process is unmatched,and the welding quality is superior to most conventional welding processes.This paper mainly studies the application of laser welding in the polar ear of lithium battery.With 0.44mm thick 1060 aluminum alloy and 2mm thick T2 copper lap joint,laser welding is used to study the welding process of copper and aluminum dissimilar metals,and the influence of laser welding process parameters on weld formation is explored.By changing the laser amplitude,laser cycle,welding power and welding speed and other process parameters,the effects of different process parameters on the macro-morphology,micro-morphology,phase composition and mechanical properties of welded joints were studied in detail.,the optimal welding parameters of the Al/Cu laser welded joints The laser amplitude is 0.7cm,the laser period is 0.45s,the welding power is 78%of the rated power,and the welding speed is 185mm/s,0.44mm thick 1060Al and 2mm thick T2 copper The quality of the laser welded joints is gooFirst,the micro-regions on the aluminum side and copper side of the weld were observed by a super-depth-of-field microscope,and it was found that when the laser amplitude decreased,the grain size of the copper side joint showed a decreasing trend;on the contrary,the aluminum side showed a decreasing trend as the amplitude decreased.,the grain size shows an increasing trend.When the laser period decreases,the grain size tends to increase,while the grain size on the Al side is opposite.When only changing the welding power,when the welding power is 68%and 78%of the rated power,the grain size is small.When the welding speed is changed,it is found that when the welding speed is 185mm/s,the grain density is higher,and the grain distribution is also smaller.more uniform.Secondly,energy spectrum analysis and phase analysis were carried out by EDS and XRD.The results showed that at the laser welding interface of copper-aluminum dissimilar alloys,intermetallic compounds were formed due to the interaction between Al and Cu.The XRD results showed that Al and Cu were found.There are mainly several intermetallic compounds such as Al Cu,Al₂Cu,Al Cu₄,Cu₉Al₄and so on.Finally,through shear force experiments and fracture morphology analysis,the results show that when the welding speed is 165mm/s,the shear force is the largest,the maximum is1613N,which reaches 72%of the maximum shear force of the copper base.The main method of fracture of the joint under the action of shear force is the toughness-brittle hybrid fracture method.