The Simulation On Microstrucure Evolution Of Alumina Composite Ceramic Tool Material

Ceramic materials Ceramic cutting tools with high temperature,wear resistance,high hardness,good chemical stability,etc.,which are widely used in precision machining,but its lower fracture toughness,limiting its scope of application in the field of processing.The arrangement and distribution of the microstructures directly affect the mechanical properties of the material.Therefore,by simulating the evolution of microstructure during sintering and predicting its mechanical properties,can shorten the tool development cycle,reduce production costs and increase production efficiency.This paper starting from the grain boundary migration theory of grain growth,the factors influencing the grain growth are analyzed,and the classical Monte Carlo simulation method is improved.The addition of stomatal phase in the tissue using Matlab software,not only makes the simulation closer to the actual sintering conditions,but also improve the simulation efficiency,the content of this paper is as follows:(1)The effects of the second phase content,the second phase particle size,the ratio of the grain boundary energy,the sintering temperature and the sintering pressure on the microstructure were investigated.Simulations show that the higher the content of the second phase and the smaller the particle size,the more obvious the grain refinement effect is,and the higher the proportion of the second phase particles with “ intragranular ”distribution is;when the ratio of the grain boundary energy of the two phases is the same The second-phase particles with "intragranular" distribution accounted for relatively high,but the pinning effect of the second phase particles on the matrix phase was not obvious.When the two-phase grain boundary energy ratio was different,the situation was opposite;the higher the sintering temperature,the faster the grain growth,the higher the proportion of the second-phase particles with “intragranular” distribution;the sintering pressure has no obvious influence on the microstructure;By changing the above parameters,the second comparative example with "intragranular" distribution can be controlled between 23.5%and 27.5%.distribution can be obtained by changing the above parameters.The proportion is controlled between 23.5% and 27.5%.(2)A BP neural network was established.The trained network was used to predict the mechanical properties of the simulated tissue in the paper,and the microstructure was linked with the mechanical properties.The results show that the second-phase content of the "intragranular" second phase particles accounted for as high as 27.6%,its high bending strength,hardness and fracture toughness are lower;when the content of the second phase,the sintering temperature,and the sintering time are different,the proportion of the“intragranular” second phase of the obtained structure is both 23.5% to 26%.In this range,the proportion of the “intragranular” second phase increases,three kinds of mechanical properties all have different degrees of improvement.(3)The hot-press sintering experiment of composite ceramic tool material was designed and carried out.The fracture morphology was observed and the mechanical properties of the specimen were measured.The simulation results were close to the microstructure simulation results and mechanical properties prediction results.