Effect Of Multidirectional Forging Process On Microstructures And Mechanical Properties Of 6082 Aluminum Alloy

6082 aluminum alloy is a medium strength aluminum alloy with many advantages.It has been applied more and more widely in the automotive field.However,the plasticity and strength of the alloy still need to be improved to meet the increasingly demanding market.Multidirectional forging is a typical large plastic deformation process.It has the advantages of simple technology,low cost,and can prepare massive fine grain materials and can be directly applied to industrial production.Therefore,it is of great practical significance to study the multi-directional forging process of 6082 aluminum alloy.Based on the thermal simulation test and mathematical regression analysis,the dynamic recrystallization model of 6082 aluminum alloy was obtained.The effects of multi direction forging technology on the fabric and properties of 6082 aluminum alloy were studied by means of numerical simulation,multi direction forging test and metallographic microscopy.The main contents are as follows:(1)The hot compression test of 6082 aluminum alloy is carried out by using the Gleeble-3500 test machine.The dynamic recrystallization model was established by mathematical regression analysis and metallographic analysis of the experimental results.The model consists of three parts,the dynamic recrystallization critical strain model,the dynamic recrystallization percentage model and the dynamic recrystallization grain size model.(2)Based on the dynamic recrystallization model of 6082 aluminum alloy,the hot compression process of 6082 aluminum alloy was simulated.The reliability of dynamic recrystallization model was verified by comparing the axial stress and microstructure.Then the multi direction forging process is simulated,and the metal flow and the equivalent strain in the multi direction forging process are analyzed.According to the simulation results of microstructure,the results show that when the forging temperature is 450 ~500,the deformation speed is 40mm/s,and the best grain refinement effect is achieved in sixth passes.(3)According to the optimum parameters provided by the simulation results,an isothermal multi-directional forging experiment of a 6082 aluminum alloy with three channels was carried out..The results of low fold microstructure of one pass sample cross section verify the accuracy of the microstructural simulation of a multidirectional forging.The metallographic results of two pass and three pass samples indicate that the grain refinement effect and grain size confirm the accuracy of multi-directional forging microstructure prediction.Combined with the change of mechanical properties,metallographic analysis and tensile fracture analysis,the results show that during the three pass,sufficient dynamic recrystallization is observed and grain refinement is more complete.