Modelling the heat transfer of an antioxidant coating heating system in wide temperature and simulation

Abstract

MoSi2 is regarded as the most potential coating material in high-temperature application. The present aims to explore a feasible resistance direct heating technique for thermogravimetric heating in the wide-temperature range (773–2573 K) of MoSi2 coating. The physical heat transfer model is derived for the first time. Furthermore, based on the method of finite element analysis, heat distribution and heat transfer mechanism of the surface of MoSi2 coating material before and after oxidation are discussed. The research indicates that surface heat distribution is non-uniform, and coupling effect results in the maximum heat occurs in the center area of MoSi2 coating surface. When electric voltage increases ranging from 1.4 V to 1.7 V, the maximum temperature of surface increase from 2073 K (service temperature) to 2303 K (melting temperature) before the oxidation. During oxidation, the maximum temperature of surface quasi-linearly increases with the increasing of oxidated thickness. When the defects occur (the defect diameter is 1 × 10−3 to 3 × 10−3 m and the thickness is 0.05 × 10−3 to 0.5 × 10−3 m), the maximum temperature of MoSi2 coating surface is positively related to the defective diameter, and negatively related to the defect thickness. Especially, this paper reveals the heat transfer mechanisms and law of the MoSi2 coating, which will have a positive effect on the evaluating of fatigue failure and reliability of MoSi2 coating materials. Keywords: MoSi2 coating, Thermogravimetric heating, Heating model, Heat transfer