Research On The Influence Of Forging Process Parameters On Microstructure Evolution Of 6082 Aluminum Alloy

This thesis mainly focused on the production of 6082 aluminum alloy forging forming parts. By combining experimental study and numerical simulation, the influence of deformation, deformation temperature, deformation rate and solid solution and aging treatment parameters on the 6082 aluminum alloy microstructure evolution was studied through thermal simulation experiments and typical forging experimental study. The results could be used to guide forging process. Gleeble-3500 thermal simulation machine was used to carry out one-dimension hot compression of 6082 aluminum alloy. The high temperature flow stress data of 6082 aluminum alloy was obtained, and the true stress-strain curves were drawn through the experimental data, and the flow stress equation of 6082 aluminum alloy was established.Corresponding to the hot plastic forming process of 6082 aluminum alloy, the effect of forging process parameters on the isothermal compression and forgings extrusion was simulated. It was concluded that with the increase of strain rate at the same deformation temperature, the effective strain of the specimen increased, and the effective stress decreased gradually. During the hot extrusion, the influence of preheating temperature for mould, friction factor on forging was analyzed. The results showed that to improve the mould preheating temperature can reduce initial forging temperature and forging temperature difference; When the friction factor increases, the shear stress and the equivalent effect of the surface of the billet increases gradually; The shear stress was 22 MPa, and the equivalent strain was 3.8.The solid solution aging treatment was finished for the isothermal compression test specimen and hot extrusion forgings according to the heat treatment process specification. The microstructure of the specimen after the solid solution aging treatment was tested. The effects of deformation temperature, strain rate and deformation rate on the grain structure of 6082 aluminum alloy were analyzed. When the deformation temperature was the same, the larger the strain rate the greater the grain size. The mixed crystal phenomenon was serious when the deformation temperature was low. The effect of deformation rate on the grain size became less obvious with increasing deformation temperature. The metallographic analysis of 6082 aluminum forging after solid solution aging revealed that with the increase of initial forging temperature and final forging temperature, the recrystallization and grain growth of the surface layer of the forging were finished. The grain structure was isometric and the distribution was homogeneous.