Research On Resistance Fusion And Brazing Technology Of Aluminum Alloy And Galvanized Steel

Aluminum/steel dissimilar metal composite structure can give full play to the inherent advantages of two kinds of material.Comprehensive advantages are obvious, such as light, high strength, good corrosion resistance and so on.It has become more and more widely used in automotive, aerospace and other fields. However aluminum and steel solid solubility is low, easy to form a rigid intermetallic compound, the low resistivity and high heat conductivity of aluminum alloy leads to the alloy side there less heat production when conventional resistance spot welding of steel and aluminum, adding to quick heat dissipation, etc., heavly affect the quality of joint and limits its application. Based on the above difficulties, were carried out steel/aluminum dissimilar metal resistance spot welding experiments with adding stainless steel gasket.We chose SPCD cold rolling galvanized steel plate which widelt used in car body and2024 aluminum alloy as the research object, using the means of fixed parameters to study the welding current, electrode pressure, welding time can produce which kind of effect on the mechanical properties of welded joint, gaining the best parameters combination. The proper gasket thickness on the mechanical properties of welded joint are studied.The experimental results show that: under our experimental conditions, when the welding current change between 9ka ~ 11 ka, the mechanical properties of welded joint gradually increase and reache the highest then tend to be stable, but when the welding current is more than 11 ka, the input of welding heat is too large and cause the aluminum side splash strongly, reducing the intensity of spot welding joint.When the electrode pressure change between 0.5 KN ~ 1.2 KN, the mechanical properties of welded joint increases gradually, when over 1.2 KN, the shear of welded joint declines. When welding time change between 26 cyc ~ 32 cyc, the welded joint strength gradually increase, more than 32 cyc, the shear stress decline slowly.Under the conditian of welding current 10 ka, welding time 30 cyc, electrode pressure 1KN,under the condition of 1 KN, the shear stress increase along with the thickness(0.2mm / 0.4 mm / 0.6 mm) increasing firstly and then idecrease, at 0.4 mm the maximum shear stress come up to 5.915 KN, add the gasket, the whole joint with the gasket is strongger than the normal.