| Aluminum alloy brazing composite plate (sheet) is widely used in many heat exchangers, such as automobile radiator, automobile air conditioning condenser, evaporator and air cooling system of thermal power station with its excellent resistance corrosion, conductivity and thermal conductivity. China is a purely importing country to this type of aluminum foil since the 90’s in twentieth Century, the product quality is relatively poor, enterprise productivity is very low. Therefore, the biggest problem the domestic composite aluminum foil production facing is to improve the self-quality and yield of the composite plate, so as to break through the foreign technology, to replace imported products.4343/4A60 aluminum alloy composite brazing plate combined with good brazing energy of 4343 aluminum alloy and good plasticity of 4A60 aluminum alloy, thermal conductivity, thermal deformation and so on. The brazing performance can be improved during the brazing process, which can improve the thermal conductivity of the heat radiating fin. This paper selects 4343 aluminum alloy and 4A60 aluminum alloy as the research object, Using GLEEBLE-3500 thermal simulation testing machine to simulate and analysis rolling composite process in deformation in the of high temperature rheological of 4343/4A60 aluminum alloy plate and mechanical properties, composite plate during hot deformation constitutive equation arid determine the best rolling temperature for the composite plate; Through hot rolling makes two rolled aluminum alloy composite and cold-rolled multipass rolling thin, analysis of composite plate under different deformation and different road conditions of thick ratio distribution, organization evolution, shear strength and the interfacial bonding condition, deformation law of layered aluminum alloy composite plate in the rolling process and binding mechanism. The optimum annealing temperature and time of 4343/4A60 aluminum alloy composite brazing sheet were determined by metallographic observation and micro hardness measurement of the composite plate after heat treatment. The results show that:In the high temperature hot compression deformation of 4343/4A60 aluminum alloy, the steady state rheological behavior is present. The flow stress decreases with the increase of temperature, and increases with the increase of the deformation rate. The hot deformation process of two aluminum alloys can be expressed by the Arrhenius type hyperbolic sine function, which is related to the Zener-Hollomon parameters.The optimal composite temperature of 4343/4A60 aluminum alloy hot rolling composite is 400℃, and the composite effect is better when the rolling temperature is 400℃.The thickness ratio of equal thickness 4343/4A60 aluminum alloy was kept unchanged during the hot rolling and cold rolling. In order to obtain the thickness of the 4343/4A60 composite plate, the original thickness of the composite plate was equal to that of the same thickness. And when the rolling reduction ratio of the hot rolling process is larger, the change of the thickness ratio of the hot rolled composite plate in the subsequent cold rolling process is smaller, and the better of the two aluminum alloy.Based on the interface of the composite plate by scanning electron microscopy (SEM) and energy spectrum analysis, in the compound 4343/4A60 aluminum alloy hot rolling process,4343 aluminum alloy layer of silicon to 4A60 layer of aluminum alloy occurred certain degree of diffusion, two aluminum alloy hot-rolled composite interface with relatively strong metallurgical bonding.The optimal annealing process of 4343/4A60 aluminum alloy composite plate was determined to be 300℃,1.5h, and the composite plate obtained under the annealing condition had the best microstructure and properties. |
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