Study on temperature uniformity of workpieces in multi-layer trays inside vacuum sintering furnace for cemented carbide

Abstract

Numerical simulation has been widely used recently to study temperature field characteristics in sintering furnaces, compensating for the limitations of traditional experimental methods in obtaining temperature field data in high-temperature sintering furnaces. We established a numerical model of the transient temperature field in a vacuum sintering furnace of cemented carbide. Numerical simulation of the transient temperature field of the vacuum heating sintering process is carried out for cemented carbide, and the transient temperature fields at different times in the furnace are obtained. By comparing with the measured data, the maximum error is within 3 %. On this basis, the uniformity of temperature within the different tray layers of the cemented carbide workpieces during the sintering process and at the end moment of sintering is further discussed. The results of the study show that the insulation stage in the sintering process can effectively improve the uniformity of the temperature of the workpieces. The temperature uniformity of the workpieces located in the middle tray layers is significantly worse than that of the workpieces in the upper and lower tray layers. Assuming the middle tray layer as the symmetrical plane, the average, maximum, minimum and coefficient of variation of the temperature of the workpieces among the trays are basically symmetrically distributed. This study provides a reference for improving the local low-temperature and high-temperature zones of the workpieces in the vacuum sintering furnace for cemented carbide.