Experimental Study On Formability Of 7075-T6 Aluminum Alloy HFQ Based On Damage

7075-T6 super strength aluminum aloy has the advantages of high strength,light weight,good corrosion resistance and so on.It is a kind of good lightweight material,which is widely used in aerospace,transportation and other industries.However,the formability of 7075-T6 super strength aluminum aloy is very poor at room temperature.It is very easy to cause the crack and springback of the parts in the traditional cold stamping process.In recent years,a new forming method(Heat Treatment,Forming and in-die Quenching Process,referred to as HFQ Technology)based on warm forming on the hot stamping and die quenching process can well solve the above problems.It can ensure the formability of parts and make the parts have enough mechanical property.In the process of sheet metal forming,cracking is an inevitable problem.How to accurately predict the cracking has always been the focus of sheet metal forming research.This paper was based on the HFQ process,the GTN microscopic damage model was introduced into the study of the formability of 7075-T6 super strength aluminum aloy.The mechanical properties of 7075-T6 super strength aluminum aloy were obtained by uniaxial tensile tests at different temperatures,and then the GTN damage parameters were obtained by the finite element inverse method.The damage parameters are applied to the finite element simulation of the small punch test,and the results are compared with the experimental results.The accuracy of the GTN model in the prediction of 7075 super strength aluminum aloy is verified.At the same time,the influence of initial forming temperature and friction coefficient on the small punch test is studied by finite element simulation.The results show that with the increase of the initial deformation temperature,the formability of 7075-T6 super strength Aluminum Aloy improved,and the best temperature of forming is 400?.The friction coefficient has a great influence on the rupture time of the specimen.The larger the friction coefficient is,the smaller the maximum load is,but the influence of the friction coefficient on the maximum load is small.Finally,the finite element method is used to predict deep drawing box mold test of 7075 super strength aluminum aloy.