Simulation Of Compaction Pressing Of AlON Green Body Based On The Discrete Element Method

The AlON material is a new isotropic polycrystalline ceramic material,which can be made into transparent ceramic by high temperature sintering.AlON transparent ceramics have excellent optical and mechanical properties,especially suitable for high temperature infrared windows,so they have broad application prospects.In the sintering process of AlON ceramics without pressure,the pressing process conditions of the green body have a great influence on the quality of AlON ceramics,so improving the quality of the body is one of the important process links.In this paper,the influence factors of AlON powder compaction are studied by combining experiment with numerical simulation analysis under aiming at process of AlON powder dry pressing.Firstly,the properties of AlON material and the preparation methods of ceramic powders are introduced.The research progress of numerical simulation technology in the field of forming is summarized,especially focus on the discrete element method including the basic theory,contact model,powder search algorithm,etc.In this paper,the three-dimensional discrete element pressing model of AlON powder is established,and the density of AlON powder was simulated by unidirectional pressing in dry pressing process.The effects of particle size,continuous particle size distribution of mixed powder and pressure on the compact density were analyzed emphatically.The experimental study on dry compaction of AlON powders is carried out and compared with the numerical simulation results.The results show that the established discrete element model can simulate the compaction process of AlON powders well and select the appropriate dry compaction pressure of AlON powders,which is conducive to improving the sintering quality in the later stage.