Study On T2 Copper And 1060 Aluminum Pulsed Laser Welding

Copper and aluminum are widely used because of the good electrical conductivity,thermal conductivity,corrosion resistance,and the good ductility.But compared with aluminum,the Copper is used as a strategic resource.The use of aluminum instead of copper in industrial production can reduce the production cost.However,the physical properties of copper and aluminum are quite different,the copper and aluminum are difficult to weld.Now,laser welding is a relatively advanced new welding technology,and the laser welding has high energy density and fast cooling rate,so some researchs have used this technology to solve the welding problem with dissimilar metals.Therefore,the connection of Cu-Al dissimilar metals was studied by pulsed laser welding.Firstly,this article uses laser weld to solve the connection between Cu and Cu,then the influence of pulse laser welding parameters on the weld formation was explored at the same time.In addition,the Cu-Cu filler wire welding process was optimized.According to the characteristics about Cu-Cu pulsed laser welding of the same metal,the eutectic alloy BAg72Cu welding wire was selected and the principle of melting and brazing was adopted.Finally,the stable welding process of the Cu-Al wire laser welding weld was determined,which was the welding current was 195A,pulse width 4 ms,frequency 6 Hz,speed 100mm/min,defocus amount-1.5 mm.Secondly,the microstructure and composition of the Cu-Cu joint weld zone and the Cu-Al weld zone using multiple welding methods were analyzed by scanning electron microscope,energy spectrum analysis and X-ray diffraction analysis.The Cu-Cu filler wire welding forms a“hook”shape in the bond zone.The weld zone mainly composed of the eutectic composition of Ag and Cu,which was beneficial to obtain a relatively good quality welded joint.When the Cu-Al non-filled wire was welded,Through the XRD test,the weld zone detectec a variety of brittle intermetallic compounds between Cu and Al,such as CuAl,Cu₄Al,and?-Cu₉Al₄.When welding,Al is diffused to the Cu side after melting,and the complex metal phase will produce in the welded joints,so the welding quality will drop.About Cu-Al filler wire welding,using the BAg72Cu eutectic alloy wire as a filling material.Al side fusion zone formed about 10?m welding transition zone,the transition zone elements mainly in Ag element,the weld zone detected Ag₃Al metal phase,The reduction of Cu and Al complex metal phases indicates that the BAg72Cu silver-base wire has an inhibitory effect on the intermetallic brittle phase of Cu and Al,and the metallurgical bonding quality of the weld is well.Finally,the quality of the weld was further evaluated by microhardness testing and tensile mechanical properties testing.With reference to the mechanical properties of Cu-Cu filler and non-filled wire welded joints,the average tensile stress of Cu-Al filler wire accounts for 88.57%of Cu-Cu non-filling wire and 84.89%of Cu-Cu filler wire welding.The tensile stress of Cu-Al filler wire welded joints was 2.8 times higher than that of Cu-Al non-filled wire.The feasibility of welding Cu-Al joints with BAg72Cu welding wire under the action of pulsed laser was demonstrated.