Simulation Research On Multiphase Field Model Of 3D Eutectoid Transformation Based On OpenCL-GPU Heterogeneous Parallel

Computer modeling and simulation of material forming process is one of the important frontier fields of manufacturing science,material science and information science.Numerical simulation of microstructure is an effective method to predict and study the mechanism of internal structural transformation of materials,which has become a research hotspot.Phase-field Method(PFM)based on Ginzburg-Landau theory is one of the most effective methods to deal with the dynamics of microstructure evolution.The eutectic growth from liquid phase to solid phase has obtained many important research achievements in phase field.The eutectic growth is a transition from solid phase to solid phase derived from the theory and equation of eutectic growth.The study of eutectic growth lays a foundation for the study of eutectic growth.However,most studies are limited to two-dimensional eutectoid simulation and cannot fully show the growth morphology of the microstructure.Therefore,it is very important to carry out three-dimensional multi-field coupling eutectoid transformation simulation research.Previous studies mainly focused on simulating the internal growth mechanism of phase transition,but impurities or interfaces may affect the diffusion of solutes in the actual phase transition process.Therefore,it is of great significance to study the effect of baffle on phase transition.Using CPU to solve the multi-field coupled 3D phase field model cannot solve the bottleneck problem of low computational efficiency.Therefore,it is very necessary to make use of the powerful floating-point computing ability of GPU itself to expand the computational scale,improve the computational efficiency and complete the solution within a reasonable time.At present,there are a variety of mature GPU parallel computing solutions,but the hardware devices produced by different manufacturers cannot use a unified programming framework to realize program development,which hinders the wide application and rapid development of HPC.OpenCL emerged at the right moment,which can be executed on different heterogeneous platforms and make full use of GPU hardware resources to improve program performance,and has a broad development prospect in many fields.The main research work of this paper is as follows:Based on the KKSO model,a three-dimensional eutectoid multiphase field model of the coupled phase field and solute field is established.The eutectoid growth process of Fe-C binary alloy was simulated by using OpenCL-GPU isomeric parallel computing technology,and the phase field model in large scale three-dimensional region was solved.The effects of different shapes and different positions of baffles on the synergistic growth of lamellar pearlite were studied.The end-to-end growth process of pearlite was simulated.The effects of different initial undercooling degrees and different diffusion coefficients on the growth morphology of lamellar pearlite were studied.The simulation results of OpenCL-GPU parallel computing are compared with the classical theoretical values and the existing simulation results of other researchers to verify the correctness and effectiveness of the parallel computing solution method.The results show that GPU computing efficiency is up to88 times faster than serial CPU,and as the simulation scale increases,GPU acceleration performance is higher;the presence of baffles directly affects the evolution of pearlite morphology,The growth of pearlite under the baffle will be restricted,and the morphology of pearlite passing through the gap of the baffle will change;when the baffle is located directly above the interface between cementite and ferrite,the cementite on both sides of the baffle merges Because of the irregular shape,the carbon atoms at the front of the cementite phase cannot meet its growth requirements,and the growth stops,and the adjacent ferrites merge into one phase.Therefore,the presence of the baffle can control the growth morphology of pearlite.Ferrite and cementite grow together perpendicularly to the solid-solid interface;with the continuous increase of the initial subcooling,the morphology of the eutectoid layer changes in sequence: cementite stops growing ? the amplitude of the layer increases ? regular and symmetrical growth ? inclined growth ? layer merging;with the increase of the diffusion coefficient,the growth rate of the lamellar pearlite microstructure linearly increases,and the morphology of the pearlite frontier does not change significantly.