3D-Numerical Simulation Study On Mg And Its Alloys Dring ECAP Based On Smoothed Particle Hydrodynamics

Magnesium and its alloys have obtained high strength and high ductility after Equal Channel Angular Pressing?ECAP?plastic processing,which make their applications extensively expanded.For Magnesium and its alloys the less sliding system during ECAP process at room temperature leading more likely to crack,ECAP package process which can effectively solve the the cracking problem and successfully realize the room temperature ECAP process of magnesium and its alloys.The numerical simulation can clearly show the entire ECAP process.However,the current grid simulation method has great limitations in dealing with the ECAP damage evolution process.Therefore,this paper uses Smooth Particle Hydrodynamics?SPH?to simulate the damage evolution process of ECAP.The main research contents are as follows:First of all,this paper builds 3D simulation ECAP mathematical model incorporating damage prediction based on the SPH method,Writes parallel SPH method program using OpenMP technology and applies to3D numerical simulation of magnesium and its alloys ECAP process.Adopt the modified penalty function method to process the boundary.What's more,adopting the SPH method parallel program build in this paper to conduct 3D simulation respectively during ECAP process of extrusion velocity as 1mm·s^-1and 5mm·s^-11 pure magnesium and pure magnesium canned with two types of materials at room temperature.Comparing the SPH simulation results with the experimental results to verify the validity of the 3D parallel SPH method program build herein.Finally,Introducing friction and correcting the mathematical model build in this paper.Conducting a numerical simulation of the slider slides down the slope to verify the validity of the mathematical model build herein.adopting the new model and DEFPRM-3D to conduct 3D simulation respectively during ECAP process of extrusion velocity as5mm·s^-11 AZ31 magnesium at 250?.Analysising the effects of different friction factors on deformation uniformity.Discussing the feasibility of the modification model of parallel SPH method program build herein to simulate the friction condition in ECAP process.