Simulation Of Powder Sintering And Parameter Optimization Design Of AlON Based On The Discrete Element Method

Spinel AlON ceramics are one of the most promising structural-function integration polycrystalline transparent ceramic materials.It has the characteristics of high temperature resistance,corrosion resistance,high strength,high fracture toughness,and also has optical properties.Based on these advantages,AlON ceramics have broad application prospects in many engineering fields.AlON ceramics are mainly formed by sintering technology.The particle size distribution of the powder will have a great impact on the relative density of AlON ceramics during sintering.Therefore,Looking for the optimization principle of the particle size distribution of the powder,Clarifying the effect of particle size distribution on the relative density of AlON ceramics is the focus of this study.In this paper,simulation of AlON powder sintering is carried.Taking the particle size distribution as parameters,the influence of varied parameters on the simulation results of AlON powder sintering is studied.The optimization principle of the particle size distribution is proposed based on these results.Firstly,the application prospects of AlON ceramics and powder sintering mechanisms are introduced.The research progress of related numerical simulation methods and sintering model in sintering field are reviewed.According to the contact characteristics of particles in each sintering period,the sintering model of AlON powder is established and the simulations of powder sintering are carried out with pressure instead of temperature.The feasibility of the scheme is verified through the comparison of the experimental and simulation results.The simulation results of unimodal and bimodal powder,bimodal powder with different particle size distribution widths and bimodal powder with different particle size truncation methods are analyzed.Based on these results,the optimization principle of particle size distribution is proposed,that is the width of particle size distribution should be set reasonably to ensure there is a certain difference in particle size between particles,while controlling the volume fraction of small and large particles in the powder.The sintering simulations of unimodal powder with optimized particle size distribution are carried out,it shows that the powders with improved particle size distribution parameters have significantly higher growth rate of relative density and average grain size than the powders with unmodified parameters and also proves that optimization principle has applicability to unimodal powder with different particle size peaks.