A Study On High-temperature Flow And Fracture Behaviors Of2024Aluminum Alloy

2024aluminum alloy is widely used to manufacture aerospace vehicles structure and load-bearing components in the aerospace industry. Though there are some researches about influence law of composition, heat treatment and creep ageing process on performance of2024aluminum alloy, its high-temperature flow and fracture behaviors still need to be further investigated. High-temperature flow behaviors of2024aluminum alloy are investigated through experiments and theoretical analysis. The phenomenological constitutive model and ductile damage model are established to describe the high-temperature flow and fracture behaviors of2024aluminum alloy. The main contents and results are as follows:(1) The effects of deformation parameters on the flow stress and microstructure evolution of2024aluminum alloy during hot deformation are investigated through hot tensile experiments and fracture morphology observation. The results show that flow stress of2024aluminum allov incrense with increase of strain rate or decrease of the deformation temperature. The volume of the void increases with the increased temperature and decreased strain rate.(2) Based on the experimental results, the phenomenological constitutive models are established, considering the coupled effect of strain rate, strain and forming temperature on the high-temperature flow behavior. The results show that the maximum error between the predicted and measured results is only6.3%. So, the established constitutive model can accurately predict the flow behavior of2024aluminum alloy at elevated temperature.(3) Based on the DEFORM-3D software, the material properties for the finite element simulation are amended by the method of trial tests. The hot tensile process is simulated and the results indicate that the established material model can be properly used for the hot tensile process.(4) Under the framework of continuum mechanics, a commonly used ductile damage model (Freudenthal model) is improved and imported into DEFORM by FORTURN secondary development, considering the effects of the deformation temperature and strain rate on the ductile damage. The results show a good agreement between the predicted and experimental results.