Short Process Technology Of Hot Pressing Forming Of Aluminum Alloy Wall Plate With Variable Thickness

Due to the characteristics of their low density,high strength-to-weight ratio,and excellent plastic deformation ability of aluminum alloy materials,it has been used more and more in the new generation of weapons and equipment,especially in the variable thickness special-shaped wallboard parts.However,its current conventional manufacturing methods are poor in profile accuracy,requiring a large number of subsequent manual calibration,and long production period.Therefore,the existing forming methods can not meet the requirements of high precision,low cost and rapid development of variable thickness profiled aluminum alloy wallboard for new generation weaponry.Aiming at the development requirement of variable thickness special-shaped aluminium alloy wallboard and its structural characteristics,this paper puts forward a hot-pressing forming process plan.The tensile deformation behavior and microstructure characteristics of 5A06 aluminum alloy were studied under the conditions of strain rate of 0.0001?0.1s-1 and deformation temperature of 300?450?.The high temperature deformation constitutive equation of 5A06 aluminum alloy was obtained by using the Arrhenius hyperbola sine function model.According to the wall model,the die of hot pressing is designed,including feature avoidance design,positioning design and die scaling design.On the basis of the above,the influence law of hot pressing temperature,hot pressing speed and friction coefficient on hot pressing of special-shaped aluminum alloy siding with variable thickness was studied by finite element simulation,and the optimum technological parameters were obtained.According to the simulated optimized forming process parameters,the hot pressing forming of special-shaped aluminum alloy siding with variable thickness was tested and verified.The results show that under the conditions of strain rate and deformation temperature,with the increase of deformation temperature or the decrease of deformation rate,the dynamic recrystallization(DDRX)gradually dominates.With the increasing of deformation amount,the grain transformation form is mainly geometric dynamic recrystallization(GDRX).By analyzing the forming load,stress strain,damage factor and other results,the technological parameters of hot pressing forming were optimized,and the optimized technological parameters were tested and verified.Finally,when the hot-pressing speed of aluminum alloy walling was determined to be 1mm/s,the hot-pressing temperature was 350?,and the friction coefficient was 0.3,the walling surface precision was relatively high,and the error was basically controlled within 0.2mm.At the same time,its tensile strength is 338 MPa and elongation is 25%,meeting the requirements of tensile strength and elongation after fracture not less than GB/T 3380.2.