Numerical Simulation And Experimental Study Of Warm-rolling Process Of AZ31 Magnesium Alloy Sheet

Magnesium alloy as a lightweight commercial metal engineering material with considerable development prospects,its application research and development fully meet the development requirements of the automotive industry,electronics industry and aerospace industry.After the magnesium alloy is rolled,the sheet properties can be significantly improved,and the properties of the magnesium alloys are different due to different rolling methods.The micro-morphology is an important factor that determines the properties of materials.Therefore,it is important to study the micro-structure and evolution of magnesium alloys during hot deformation.In this paper,the finite element software ABAQUS is used to simulate the rolling of magnesium alloy sheets(synchronous and asynchronous rolling),and the effects of different rolling process systems on the temperature field,stress strain field and rolling force of magnesium alloy sheets are observed.Moreover,comparative analysis of strain and rolling force under different rolling methods.In the numerical simulation process,the model was appropriately simplified according to the actual situation,and the constraints,loads,and contact settings were assumed.In addition,in order to be more practical,the effects of thermal convection and thermal radiation are fully considered during the simulation.In this paper,the finite element-cell automaton method(FEM-CA)is used to simulate the dynamic recrystallization of AZ31 magnesium alloy sheet.The realization method is to use ABAQUS to perform asynchronous rolling simulation of magnesium alloy sheet,formulate the corresponding rolling parameters,and then use the finite element macro analysis results as the initial conditions to couple to the recrystallization calculation model to establish the finite element-cellular automata method(FEM-CA).In view of the phenomenon of work hardening and recovery softening during the warm rolling of magnesium alloy sheets,three models are introduced in the simulation process: dislocation density growth model,recrystallization nucleation model,and recrystallization grain growth model.At the same time,based on the principle of thermodynamics,the influence of strain and strain rate on the dynamic recrystallization during the rolling process was studied,which provided a theoretical basis for the optimal control of magnesium alloy rolling through process optimization.Finally,the experiments were performed according to the asynchronous rolling simulation process.The rolled sheets were placed in different environments for cooling treatment,and the metallographic technology and electron backscatter diffraction technology(EBSD)were used to observe the microstructure of the samples,and then verify the simulation results.The results of this paper have certain reference value for the stress-strain analysis of Warm Rolling Magnesium Alloy Sheet and the study of the microstructural evolution of magnesium alloy during hot deformation.