Finite Element Simulation Of Temperature Field In High Pressure Diamond Synthesis Cavity

The finite element method is used to simulate the temperature field in high pressure synthesis cavity. Two principles for the design of cavity assembly are presented, according to the two principles, improved assembly is put forward. A three-dimensional finite element model of side heating assembly is established. Temperature distribution and the wasteland in the cavity are analyzed, and the distribution of diamond growing areas in the sample is given. The results show: the heat flow from the heater to the inside of the sample, the temperature gradient in the center of the sample is the smallest; a lot of heat lost along the axial of the sample, and the temperature drop is too large(>300?), this is also present the main reason for the large “wasteland”. When the power is 3500 W, the diamond growth region is located in the center of the sample, the growth region is largest and the quality of diamond is the best. In order to reduce the temperature drop of the cavity, the auxiliary heat source is added at the two ends of the conventional side heating assembly. By finite element analysis, the temperature distribution in the cavity is more uniform, and the total temperature drop is decreased by 30%; the wasteland region is well controlled and can be eliminated in the best synthetic power 3440 W.Our study provides a general idea for the design and improvement of high pressure synthesis assembly, It also has some reference value for the improvement of synthetic process.