Research On Stamping Process Optimization And Quality Control Of Aluminum Alloy Floor Beam

At present,with the increasing deterioration of environmental and energy issues,energy conservation and environmental protection have gradually become the important content of automobile manufacturing.Replacing the traditional body steel plate with aluminum alloy plate not only reduces the weight of the car body,but also contributes to energy saving and environmental protection,and it can also improve the safety performance of the car to some extent.Therefore,aluminum alloy is largely applied to the production of stamping for automobile part.Although there are lots of researches on the stamping law of ordinary steel sheets,people have less research on the stamping forming properties of aluminum alloys because the forming rules of aluminum alloys are different and even more complicated.When the stamping process parameters and the die face design are unreasonable,it will cause some defects such as cracking,wrinkling and large springback of the part.In order to control the defects and ensure better forming quality of the part,the finite element simulation technology is applied in this paper to reasonably predict the stamping forming rule of the aluminum alloy sheet.In this way,the process has been optimized,the number of trials has been reduced and the mold development cycle has been shortened greatly.In this paper,the floor beam of a certain model was regarded as the research object,and the drawing process and springback of the floor beam were analyzed by the sheet metal forming CAE software Dynaform.Firstly,this paper had analyzed the fundamental problem of aluminum alloy instead of high-strength steel.And the stamping performance of Alum₆HS2_U aluminum alloy sheet was determined by uniaxial tensile test,then the material model of aluminum alloy named Alum₆HS2_U is established.Subsequently,stamping process analysis of floor beam was carried out,the technologic surface and the binder surface design were also carried out.The shape and size of the blank was calculated in reverse,and two drawing process schemes of floor beam were determined:the drawing process with ends and the endless drawing process.In addition,the influence of the shape and size of different ends on the forming of parts was analyzed,and the reasonable drawing process scheme was finally determined.Secondly,the main process parameters which affected the drawing quality of the floor beam for the two schemes,including the drawing process with ends and the endless drawing process,were studied.The values of four parameters including blank holder force F,friction coefficient?,stamping speed v and mold gap c were preliminarily selected,and the influence law of various parameters on the thinning and thickening situation of floor beam was explored.It can be drawn:regardless of the scheme with ends or the endless scheme,the maximum thinning rate of the part is proportional to the blank holder force,friction coefficient and punching speed,and inversely proportional to the die gap;the maximum thickening rate is inversely proportional to the blanking force and friction coefficient,and proportional to the punching speed and the die gap.Then,the four process parameters were optimized by multiple-index orthogonal test,and it was concluded that:The sequence of the influence of four process parameters on the forming quality of the floor beam is v>F>?>c.The optimal process combination of the process scheme with ends is A₁B₄C₄D₁,that is F=600 kN,?=0.14,v=5 000 mm·s^-1,c=1.0t?t is plate thickness,mm?;The optimal process combination of the endless process scheme is A2B3C1D2,that is F=1200 kN,?=0.12,v=2 000 mm·s^-1,c=1.05t.The optimal simulation results of the two schemes are compared and analyzed.Finally,the endless drawing process and its optimal process combination are selected.It was controlled within the reasonable range with the maximum thinning rate 21%and the maximum thickening rate 6.24%.In addition,springback analysis of floor beam was carried out,and the influence law of every process parameter on springback had been explored.Then,springback compensation analysis is also carried out.After 2 times of compensation,the springback amount of the floor beam had been reduced to 2.43 mm.Finally,the stamping test of floor beam was completed.Through the repairing,debugging and shaping,the rupture and wrinkling of the part had been avoided,and the springback amount was controlled within the reasonable range,and the qualified floor beam product had been produced.