A phase field model was established to simulate the grain growth of Al₂O₃-based composite ceramic tool materials containing second phase nanoparticles and pores. The free energy parameters of the model are directly related to the surface and grain boundary energies of Al₂O₃ such that the grain growth process can be quantitatively analysed. The model was used to investigate the effects of the volume fraction and size of second phase particles on grain growth in Al₂O₃ with a certain initial pore volume fraction. Findings show that pores and second phase particles jointly hinder grain growth. When the radii of second phase nanoparticles are the same, as the number of particles increase, most of the grain boundaries occur as straight lines in the microstructure, and grain size decreases. It is beneficial to obtain fine and uniform microstructure. However, when the particles content reaches a certain level, the second phase particles tend to agglomerate at the grain boundary of matrix grains, which will result in a decrease in the properties of nanocomposite ceramic tool materials. Thestudyalsofoundthat, at a constant volume fraction of particles, with the decrease of particle radius, the grain size decreases. When the second phase particle size is reduced to 50 nm, relatively more intragranular microstructure was observed, which is considered to be the main reason for increasing the toughness of nano composite ceramic tool materials. Through analyzing the simulation results, the optimal combination of the content and size of the second phase particles can provide theoretical guidance for Al₂O₃ nano composite ceramic tool materials design and preparation.

建立了相场模型来模拟包含第二相纳米粒子和孔的Al ₂ O ₃基复合陶瓷工具材料的晶粒长大。该模型的自由能参数直接与Al ₂ O ₃的表面能和晶界能有关，因此可以定量分析晶粒的生长过程。该模型用于研究第二相颗粒的体积分数和大小对Al ₂ O _3中晶粒生长的影响。具有一定的初始孔体积分数。研究结果表明，孔隙和第二相颗粒共同阻碍了晶粒的生长。当第二相纳米颗粒的半径相同时，随着颗粒数量的增加，大多数晶粒边界在微观结构中以直线出现，并且晶粒尺寸减小。获得精细且均匀的微观结构是有益的。然而，当颗粒含量达到一定水平时，第二相颗粒倾向于在基体颗粒的晶界处附聚，这将导致纳米复合陶瓷工具材料的性能下降。研究还发现，在颗粒的体积分数恒定的情况下，随着颗粒半径的减小，晶粒尺寸减小。当第二相粒径减小到50 nm时，观察到相对更多的晶粒内微观结构，这被认为是增加纳米复合陶瓷工具材料韧性的主要原因。通过对模拟结果的分析，第二相颗粒的含量和尺寸的最佳组合可以为铝提供理论指导。₂ O ₃纳米复合陶瓷刀具材料的设计与制备。