Study On Ceramic Tool Materials And Their Cutting Performance Based On Cellular Automata Model

Ceramic tool materials have high hardness, high abrasion resistance and high stability in high temperature, it is suitable for high efficient cutting of the hard cutting materials. The developed method of the existing ceramic tool materials is experiment, which can cause to the bad design. Especially there are no systematic guidance to the sintering process microstructure design and optimization, there are no theories guidance for the new ceramic tool materials development, and it is difficult to obtain good mechanical properties.In this paper, using the cellular automata model, considering the two phase particles, sintering additives and sintering densification process, the main parameters including holding time, sintering temperature, sintering pressure are coupled into the cellular automata model. The grain growth process of Al2O3/TiN composite ceramic tool material sintering process is simulated. Finally the analysis process is validated through the sintering experiment, the results show that the simulation results and the experimental results are in good agreement with the actual sintering. This theory combining with experiment, the ATN50material is developed, and the ATCN50b composite ceramic tool materials are developed successfully. The high efficient cutting experimental studies of1Cr13stainless steel are processed. The results show that the cutting tool life and the surface roughness of the workpiece are superior to the existing several kinds of composite ceramic cutting tools and carbide cutting tools under high speed.The maximum grain orientation has an important impact on simulation process and result. The maximum grain orientation has been given, and the main parameters including holding time, sintering temperature, and sintering pressure are coupled into the cellular automata model. The grain growth simulation model for ceramic material sintering process based on cellular automaton is constructed based on the grain growth driving force theory of grain boundary energy and the curvature of the grain boundary. The ceramic tool materials sintering process of microstructure evolution are simulated. The results show that when the sintering temperature is1700℃, holding time is10min or15min, sintering pressure is32MPa, the simulation results of grain size and size distribution are good, the better sinter microstructur can obtained e. Contrasting the same process actual sintering preparation of Al2O3/TiN ceramic tool material with simulation results, sintered body of matrix, second phase particle size and the second phase particle distributionare consistent with cellular automaton method simulation results.Considering the impact of random distribution of sintering additives, based on Al2O3/TiN two-phase ceramic tool materials, the cellular automata model Al2O3/TiN composite ceramic tool material with sintering additives is established. The results show that sintering additives has obvious effect on grain refinement. Considering sintering densification process of ceramic tool materials, the cellular automata model of Al2O3/TiN composite ceramic tool material containing pores is established. Comparing the grain growth condition without hole with with hole, the results show that sintering additives can improve the ceramic sintered body density effectively. Contrasting the same process actual sintering preparation of Al2O3/TiN ceramic tool material with simulation results, sintered body of matrix, second phase particle size, sintering additives and hole distribution are consistent with the cellular automaton method simulation results.In the guidance of cellular automata simulation results, the Al2O3/TiN composite ceramic tool materials are prepared, the results show that when the sintering temperature is1700℃, holding time is10min, sintering pressure is32MPa, TiN volume content is50%, Al2O3/TiN composite ceramic tool material has the best comprehensive mechanical properties. On this basis, the Al2O3/Ti(C,N) composite ceramic tool material ATCN50b is prepared successfully. When the sintering temperature is1700℃, sintering pressure is32MPa, holding time is10min, ATCN50b materials obtain the best mechanical properties, the bending strength is910MPa, Vickers hardness is20.5GPa and fracture toughness is8.11MPa·m1/2.The cutting performance of ATCN50b ceramic tool cutting1Cr13martensitic stainless steel is studied, and is compared with the commercial SG-4, LT55composite ceramic tool that developed by the former Shandong University of Technology, AWT10A60W4T6, WZ10A composite tool materials that are developed by Shandong University and the commercial YG8, YT5, TW1carbide tool. When cutting depth ap is0.1mm, feed rate f is0.1mm/r, cutting speed v is100m/min, ATCN50b has the longest service life61min, meets the machining surface roughness requirements, the life is of116%YG8hard alloy tool, is122%of LT55and SG-4tool, is129%of YW1tool, and far higher than other tools. When the cutting speed v is260m/min, ATCN50b has the service life of30min, and meet the machining surface roughness requirements, the life is120%of LT55tool; is129%of SG-4tool and YT15tool, and far higher than other tools. The wear and failure form, the main wear and breakage mechanism of ATCN50b tool are studied. The results show that the ATCN50b tool high temperature stability is good and suitable for high efficient processing of1Cr13martensitic stainless steel, though the tool surface has a certain bond phenomenon.