Robust Design Of Aluminum Alloy Sheet Hot Stamping Process

The increasing depletion of energy and the increase in social requirements for environmental protection have forced cars to reduce their weight to achieve energy conservation and emission reduction.More and more different types of materials are being used by researchers in the automotive industry to achieve lightweight vehicles.Among them,aluminum alloys are popular in major automobile manufacturing because of their small density,high strength,good corrosion resistance and relatively low cost.It has become the first choice for automotive lightweight materials,and the application rate of aluminum alloys for structural parts of different car models has gradually increased.Due to the obvious difference in crystal structure between the aluminum alloy and the traditional steel plate,the numerical simulation theory and process parameters applicable to the stamping forming of the steel plate cannot be directly applied to the aluminum alloy hot stamping.Moreover,the traditional stamping process design often relies on the experience of R&D personnel and repeated trial and error repairs,which leads to excessive manufacturing costs and also lengthens the design cycle,resulting in low product manufacturing efficiency.And in actual production,the various parameters in the stamping process are not static,and often have a certain range of fluctuations,which will also adversely affect the quality of the formed parts.With the rapid development and maturity of numerical simulation technology,mathematical statistical methods and optimization design theory,the three can be combined to simulate the aluminum sheet hot stamping process,while taking into account the parameter fluctuations,to conduct robust design to reduce Efficient design times,predict possible defects,and find a more reasonable combination of hot stamping process parameters.In this paper,in consideration of parameter fluctuations,a robust design is carried out to explore the process parameters suitable for hot stamping of aluminum alloy sheet 7075-T6,and the following work is specifically carried out:(1)The advantages and disadvantages of the aluminum alloy sheet in the automotive industry and the domestic and international use are expounded,the shortcomings of aluminum alloy stamping research are pointed out,and the research direction of this article is proposed.(2)Research and introduce the key technology of numerical simulation and the concept of robust design.Compared with other design methods,the advantages of the approximate model in dealing with engineering problems are analyzed,and the foundation of robust design of aluminum sheet hot stamping is laid.(3)The quality defects in hot stamping of aluminum alloy sheet were analyzed,the influence of possible fluctuating process parameters on the quality of formed parts was studied,and the sheet was quantified using forming limit diagram,wrinkling and average thinning rate.Criteria function for evaluating the stamping quality of materials.(4)Take the B-pillar of an automobile model as an example,use numerical simulation software to establish a finite element model design to complete the orthogonal test,and use the sensitivity factor screening method to screen the main process parameters for robust design,and use the stamping quality evaluation criteria As a basis,the billet temperature,friction coefficient and blank holder force were selected as design variables,and an interpolation-type approximate model was used to robustly design the selected process parameters.After robust design,through simulation and actual stamping parts before and after comparison test,proved the necessity,practicality and reliability of the robust design method.