Study On The Rolling And Heat Treatment Process Of3003/4004Clad Aluminum Alloys

This paper fabricated3003/4004aluminum alloy composite plates mainly through a combination of hot-rolling and cold-rolling. The process has gone through homogenizing annealing, rolling and final annealing experiments. By analyzing and mechanical testing of homogenization, rolling and final annealing organization, the paper discussed the influence of the homogenization treatment before rolling, rolling and annealing treatment after rolling on the mechanical properties of the multi-layer sheet organizations, and explored the best rolling and heat treatment process of aluminum alloy composite ingot, in order to get well-organized3003/4004aluminum alloy multi-layer sheet of excellent mechanical properties. The results show that the cast interface of3003/4004composite ingot is relatively flat. The Mn element is distributed at the3003alloy side, and there exists segregation; the alpha-Al matrix of4004alloy side presents the characteristics of dendritic morphology in a vertical interface direction, and the eutectic silicon, mainly flaky and acicular, is distributed between dendrites. Microstructure are refined and segregation is reduced with the rise of the temperature of homogenization, while the second phase precipitation increased with the extension of the time of homogenization. The reasonable process system is500℃,8h.The microstructure topography of the composite plate after rolling presents the formation of fibrous tissue along the rolling direction. At the same coating rate and total deformation, the large pass reduction contributes to the refinement of the matrix structure and the second phase, and facilitates the subsequent cold rolling. The processes with pass reduction of lmm×5pass,1.5mm x6pass,2×5pass,1.5mm×4pass,1mm×9pass are optimal hot rolling processes; the strength of the cold-rolled sample is the highest when the amount of deformation in the first pass is18.75%, and Si and Mg element were dispersed in the3003matrix to improve the strength of the matrix. With the increase of the amount of deformation in the first pass, the strength is reduced at first, and then increased, whereas plasticity decreased. The amount of deformation in the first pass of the rolling process set as18.75%is the reasonable cold rolling process.When annealing holding time is the same, the hardness of the multi-layer sheet is decreased as the heating temperature rises, and the hardness has a sharp decline when the temperature reaches recrystallization temperature. When the heating temperature is the same, longer holding time leads to lower hardness. Therefore the reasonable annealing process is360℃,1h.