Simulation Of Microstructure Evolution Of Ceramic Cutting Tool Based On 3D Cellular Automata Method

Micro-nano composite ceramic tool materials solve the shortcomings of poor fracture toughness of traditional ceramic tool materials,and are now the focus of research on ceramic tool materials.Due to the long cycle and high cost of developing new micro-nano composite ceramic tool materials by the traditional"trial and error method",more and more scholars use computer simulation methods to simulate the microscopic Tissue evolution process to optimize the sintering process and provide a theoretical basis for the research and development of micro-nano composite ceramic tool materials,thereby achieving the purpose of reducing research and development costs and improving research and development efficiency.This paper takes TiB₂-TiC-SiC as the research object,uses the three-dimensional cellular automata method to simulate the microstructure evolution process of the micro-nano composite ceramic tool material in the actual sintering process,and couples the main sintering process parameters and pores of spark plasma sintering into the model In order to optimize the sintering process parameters,it provides guidance for the design and preparation of micro-nano composite ceramic tool materials.The specific research content of this paper is as follows:On the Visual Studio 2019 development platform,using the C++language and calling the Open GL graphics interface,a software system for simulating the microstructure evolution process of the micro-nano composite ceramic tool material was designed and developed based on the three-dimensional cellular automata method.The software system can simulate the microstructure evolution of the spark plasma sintering of micro-nano composite ceramic tool materials,and output data such as three-dimensional simulation results,two-dimensional cross-sectional diagrams,average equal-volume spherical radius of grains,and number of grains.A three-dimensional cellular automata model for the microstructure evolution of single-phase ceramic tool materials was established,and the effects of the maximum orientation value Q value,sintering temperature,sintering pressure,and holding time on grain growth were studied.The simulation results show that the simulation results are better when the Q value is6000;the grain size increases with the increase of the simulation time,and due to the limitation of the simulation space,the number of grains decreases with the increase of the simulation time;the sintering temperature is increased appropriately It will promote grain growth;compared with the influence of sintering temperature on grain size,the influence of sintering pressure on grain size is small;the angle at the three grain boundaries of grains tends to be 120°,and the grain boundaries are mostly six The grain growth index of the model is 0.44,which is close to the theoretical grain growth index,indicating that the simulation process of the model is stable and reliable.On the basis of the three-dimensional cellular automaton model of single-phase ceramic tool materials,the microstructure evolution process of micro-nano composite ceramic tool materials in actual sintering was further studied,and the microstructure of TiB₂-TiC-SiC micro-nano composite ceramic tool materials was established Evolved 3D cellular automata model to study the effects of nanometer content,sintering temperature,sintering pressure and holding time on grain growth.The simulation results show that the nanophase content has a pinning effect on grain growth,and the more nanophase content,the stronger the pinning effect and the smaller the grain size;when the sintering temperature is 1600℃,the sintering pressure is 40 MPa,and the When the time is 7 minutes,the grain size of the micro-nano composite ceramic tool material is uniform,and the micro-nano composite ceramic tool material with ideal microstructure can be prepared.According to the sintering densification theory,the pore migration algorithm was studied,and the three-dimensional cellular automaton model of the microstructure evolution of the micro-nano composite ceramic tool material containing pores was established.The results show that the grain size of the model containing pores is smaller than that of the model without pores,and the pores will hinder the growth of grains;Prolonging the sintering time properly can promote the discharge of pores and increase the density of materials;the sintering temperature is 1600℃,sintering When the pressure is 40 MPa and the holding time is 7 min,the grain size of the micro-nano composite ceramic cutting tool material is uniform and the compactness is better.Guided by the simulation results,the TiB₂-TiC-SiC micro-nano composite ceramic tool material was prepared by the spark plasma sintering process.The correctness of the simulation results was verified by the experimental results,and the material components were optimized.The experimental results show that at a sintering temperature of 1600℃ and a holding time of7 min,the volume fraction of TiB₂is 69%,the volume fraction of SiC is 20%,the volume fraction of nanoparticle TiC is 10%,and the volume fractions of MgO and Ni are average.When the content is 0.5%,the TiB₂-TiC-SiC micro-nano composite ceramic tool material has a better microstructure,and its comprehensive mechanical properties are optimal.