The Research Of 6061 Aluminum Alloy Sheet Stamping Forming Springback Problem

With the continuously improvement of the energy saving requirement,Aluminum alloys is a kind of material with a series of advantages,such as low density,corrosion resistance and so on,therefore they are widely used in automobile manufacturing.But the formability of aluminum alloys at room temperature is bad and likely to develop cracks or springback defects,so that limits the application of aluminum alloys as the lightweight material in the automobile industry.In this paper,with cold stamping process of aluminum alloy auto parts after the formation of the springback phenomenon as the research object,through the means of combining the test and finite element simulation technology to solve the springback problem.The paper focused on the 6061 aluminum alloy plate in cold stamping process the springback phenomenon.To do uniaxial tensile test of 6061 aluminum alloy sheets of different cut samples with different angles(0 °,45 ° and 90 °),in order to study the anisotropy of aluminum alloy and calculate the strain hardening index n value and plastic strain ratio r value.To design the three points bending test,study the different thickness and bending angles influence on springback amount;Adopt the suitable material model for three points bending finite element simulation analysis,and draw the same data with the actual test,and then research unit type,number of integral points,such as cell size effect on the precision of springback prediction.Using the above material models obtained from the experiment and optimized parameter in numerical simulation software for a certain automobile parts for stamping process of finite element analysis,and research influence of theblank holder force,friction coefficient and drawbead,punching and trimming process on the springback,and then compensate the springback until to meet the requirements of the parts.By the previous investigation,Get three directions for cutting the 6061 aluminum alloy tensile sample should with strain curve,and calculate the n and r value,found that the anisotropy is not obvious,and provide a basis for material parameters in finite element analysis of bending springback.Three point bending test and finite element simulation of the same thickness and bending angles of size effect on the springback amount rule,and in the finite element analysis of the optimized process parameters,the springback prediction more accurate.Finite element analysis was carried out on the whole forming a study,increase the drawbead to control the rebound effect is obvious,and blank-holder force,friction coefficient,stamping velocity influence on the springback law,finally after springback compensation,meet the requirements of parts for the auto parts mould processing and is of important guiding significance for practical production.