Discrete Element Method Simulation And Experimental Investigation On The Compaction Process Of Pressure-sensitive Ceramics Material

As a kind of widely used functional ceramic, pressure-sensitive ceramic material plays a very important role in people's daily life. The main research work in this paper are following :The performances of the pressure-sensitive ceramic material are not only affected by the material itself, but by the different molding process conditions. While the effects of ceramic powder material molding process conditions are very volatile, using the experimental method to optimize the compaction conditions will consume large amounts of resources. In this paper, the compaction process of ceramic materials was investigated, the discrete element method (DEM) simulation and experiment process of the compaction process of ceramic material under different compaction conditions were carried out, the compaction technology's affect on the physical performance of the molded green-body was discussed. And it is hoped that the research in this paper can provide some theoretical basis for compaction experiment.The main research work in this paper are following :In the first chapter, the characteristics and application of pressure-sensitive ceramic material was presented, as well as the forming technology and mechanism of ceramics material was expounded. The research status quo of ceramic powder material compaction were discussed both at home and abroad through the literature investigation, together with status quo about using simulation methods on ceramic compaction research. The advantage of using discrete element method to research the compaction process of powder material and the significance of this paper were proposed;In the second chapter, the development and theory related to discrete element method was presented, and a suitable discrete element model suited for the ceramic powder materials was choose. The theory of PFC software based on discrete element method as well as its calculation method and assumptions was introduced;In the third chapter the similarity principle and the reasons for importing the similarity theory for the discrete element method model in this paper was introduced. The discrete element model based on the similarity theory was set up, and the parameters' relationships between the model and prototype were obtained. The parameters of discrete element method model were adjusted, the adjust method and the process were detailed introduced, finally the micro parameters of ZnO and Bi2O3 were obtained; In the fourth chapter discrete element method simulation and experimental investigation on the compaction process of pressure-sensitive ceramics materials under the different compaction environments, compaction patterns and different sizes of the molds were researched. The affection of gravity on the mechanical property of molded green-body, From the mechanism analyzed the different factors of modeled green-body under the gravity and micro-gravity environments, meanwhile, in combination with the compaction experiment under the gravity environment to verify the correctness of the simulation process were discussed; On the conditions of single-axial compression and two-axial compression, the mechanical properties of the modeled green-body were different, the reasons for the differences from the case of microscopic were analyzed; through the method of experiment modeled compaction process of the ceramic powder by single-axial and two-axial patterns, different pressure-sensitive performances of the ceramic wafers were presented; the mechanical properties of the modeled green-body were different by choosing different size moulds to simulate the compaction process, the reasons of this phenomenon were analyzed.Finally, summarization and prospect were presented in this paper.