Study on the temperature uniformity of workpieces inside an annealing furnace

A numerical analysis model of the transient temperature field was established to address the issue of temperature field measurement in a silicon carbide annealing furnace. Numerical simulations of the vacuum annealing process yielded temperature distributions at 550 °C, 1200 °C, and 1700 °C. Real-time temperature measurements using internal thermocouples were conducted at two points within the furnace, showing actual temperature variations. The comparison between simulated and measured data revealed that the maximum error during the holding stage was within 3 %. Based on this, an analysis of the temperature distribution inside the silicon carbide vacuum annealing furnace was performed. The results indicate that increasing the holding temperature during the annealing process effectively reduces the time needed for the workpieces to stabilize at a uniform temperature and improves temperature uniformity by the end of the process. Additionally, by the end of the annealing process, the highest temperatures of the workpieces are concentrated primarily in the middle pieces. The temperature difference among workpieces near the center is minimal, remaining within 2 °C. By the end of the holding phase, 43.64 % of the workpieces in the furnace meet the process requirements. This study offers valuable insights for the structural design and temperature control of silicon carbide vacuum annealing furnaces.