Dynamic Mechanical Properties Of Extruded6063 Aluminum Alloy

6063 aluminum alloy has the characteristics of heat treatment,medium strength,corrosion resistance,impact resistance and easy to be electroplated.It is widely used in automobile,aviation,aerospace and other fields.Its structure is often subjected to dynamic loads such as impact and explosion during service.Therefore,it is of great significance to explore its dynamic mechanical characteristics.In this paper,6063-t4 aluminum alloy was treated by solid solution and artificial aging.Static and dynamic compression tests were carried out on aluminum alloy samples before and after heat treatment by electronic universal material testing machine and split Hopkinson pressure bar.Through the analysis of test data,the dynamic mechanical properties of 6063 aluminum alloy under different heat treatment systems were comprehensively studied.The main research contents are as follows:(1)6063-T4 aluminum alloy was treated by solution treatment at different temperature and time.The microstructure of the sample was observed by metallographic microscope.It was determined that 565?/1h solution was better,and a large number of second phase was dissolved into aluminum matrix.On this basis,6063-T6 aluminum alloy was obtained by artificial aging treatment at 180?/6h.(2)The static and dynamic compression tests of 6063 aluminum alloy in two heat treatment states were carried out at room temperature.Strain rate effect and processing hardening phenomenon existed in both heat treatment states,that is,the rheological stress of the materials will increase with the increase of strain rate;and in the dynamic impact of the same strain rate,the peak stress of 6063-T6 aluminum alloy is higher than that of 6063-T4 aluminum alloy,which indicates that the solid solution aging has strengthened the alloy;the structure after impact forms streamline deformation zone along the shear stress direction,and the dynamic recrystallization occurs,and the refined grains are distributed along the deformation zone.(3)The modified J-C constitutive equation was constructed,and the dynamic compressive stress-strain curves of 6063-T4 aluminum alloy under different strain rates were fitted by using the modified J-C constitutive equation.The constitutive model can well describe the deformation behavior of the material in the range of different strain rates.(4)The dynamic mechanical constitutive model of 6063 aluminum alloy was established by using BP neural network improved by LM algorithm.The obtained constitutive model can accurately predict the stress change trend.Compared with the classical J-C constitutive model and BP neural network constitutive model,it is found that the accuracy of BP neural network constitutive model is higher.