| Solid-phase sintering is the most crucial step during the preparation of ceramic materials, and it plays a decisive role on the performance of product. The significance of powders’solid-phase sintering was described. An overview of the classic sintering theories on the different sintering stages was introduced. The research status of the area is summarized from the physical mechanism, theoretical models, research methods, and other aspects. The Monte Carlo method and the phase-field dynamic model of solid-phase sintering are improved. Based on this, some typical sintered theoretical issues such as the unstable neck growth and the large pore contraction process are researched. The sintering model was further discussed using the in situ synchrotron radiation CT (SR-CT) experiment. The establishment of a two-dimensional, three-dimensional computational model based on the SR-CT experiment is carried out. By comparative analysis of experiment and simulation results, the reliability and availability of the sintered numerical model are improved; the prediction of actual sintering process is realized.1. The computing models of the microstructure evolution during solid-phase sintering are improved. The deficiencies of classic Monte Carlo algorithm are discussed, such as not conserved in the quality, and the sintering mechanism is not enough. The dynamic conservation algorithms and a variety of sintering mechanism are introduced, improve and perfect the Monte Carlo model. A three-dimensional solid-phase sintering phase field simulation is achieved for the first time In the international arena. Particles rigid body translational and rotational in the stress field is analyzed. By spectral method and GPU parallel computing platform, a substantial increase in the computational efficiency of the phase-field method is carried out. Classical sintering theory and quantitative analysis of the improved sintering model verified the reliability of the model.2. Two classical sintering theory are researched based on the improved models: the unstable neck growth and large pore contraction process. By researching the three-particle model, it is verified that even if the shape of the particles and the contact portion is completely symmetrical, the special particle arrangement will lead to the emergence of unstable neck growth. The double hemisphere model is used to research the unstable neck long process. The results show that the grain boundary stress field during rotation of the particles plays a dominant role. The3D large pore contraction proved dominant diffusion mechanism controlled pore morphology; grain boundary stress is a major factor leading to the large pore contraction. The research, results improve the classical sintering theory.3. Two-dimensional Monte Carlo model based on synchrotron radiation CT experiment are realized. Grain growth kinetics analysis of the numerical model is carried out to discuss the method for determining the key parameters-ratio of surface energy and grain boundary energy (Jss/Jsv). The comparative analysis of the experimental and simulated microstructure evolution and grain growth index is finished. A three-dimensional phase-field model based on synchrotron radiation CT experiment for the first time. The three-dimensional structure obtained from the simulation is analyzed and compared with synchrotron radiation CT three-dimensional reconstruction of the experimental results. The quantitative analysis of the experimental and simulation results verified the reliability of the model. The usefulness and predictive ability of the numerical model are dramatically increased.In this paper, the improvement and optimization of the sintering model are achieved. Some typical sintering theoretical issues are improved. Two-dimensional, three-dimensional sintering model based on synchrotron radiation CT experiment are established. A prediction of the actual sintering process is achieved through mutual authentication by theory, experiment, and simulation. |
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