Phase Field Method For Microstructure Evolution Of Powder Ceramic Sintering

Ceramie sintering process is complicated influenced by environmental factors. Computer aided simulation applied to the powder ceramic sintering simulation process in order to explore a variety of external factors and different sintering material on ceramic performance and cost savings. The phase field method is a diffusion field interface model and most widely used in present-day. Variables of the orientation field and concentration field are continuous changing with time and space in order to track microstructure evolution all the time. These could be more intuitive and more approaching with the actual sintering process. In this paper, the phase field method using in microstructure evolution of powder ceramic sintering were discussed as following1. Computer calculation used for simulation the ceramic sintering process of three-phase ceramic (combined with two solid phases and a gas phase) for the first time. We build a three-phase free energy function, and use the phase field method to study on it. In this work, we considering gas existing in actual production process as another phase, and extended the model of early works into a three-phase model hired for simulation the ceramic sintering process of three-phase ceramic.2. Analysis of different porosity ceramic powder sintering simulation process using the linear fitting method. Draw the size of the pores distribution maps, the linear fitting curve。Get the reveal of stomata grew up as the sintered aggregate. Low porosity completely ruled out, the high porosity of the pores showing irregular shaped. The presence of stomata plays a pinning effect on grain growth, to reduce the elastic stiffness of the material, to improve the damage resistance.3. This is the ideal state of the refractories. The presence of pores of the solid-phase sintering grain changes slow down, and small grain. This is a good guide for grain refinement to improve the mechanical properties of ceramics.Simulated images are consistent with the actual ceramic SEM photos indicates the correctness of our model. The model can be applied to two different solid powder sintering process, especially like Al2O3-SiC and SiC-TiC ceramic used for fire-resistant-to guide the actual production.The above study reveal the role of process and its evolution in the sintering process, and give some theoretical modeling and feasibility analysis to optimize the properties of ceramics in actual production.