Establishment Of Mathematical Models And Research On Thermal Barrier Effect Of Thermal Barrier Coatings

Thermal barrier coatings provide excellent properties including: extreme thermal resistance, good erosion resistance, and low thermal conductivity. They make it possible to reduce the operating temperature and increase the service life of the components. Thermal barrier coationgs have a wide application perspective in spaceflight, chemical industry, metallurgical industry, and energy sources. Heat resistance is the most important performance for thermal barrier coatings. The investigation of the thermal properties of coatings, especially thermal conductivity, is extremely important since the thermal efficiency of the coating, as judged by the temperature drop across the coating, depends on its thermal conductivity. The research of the effect of inner and outer factors on the thermal barrier effect went along combining of the temperature and inner microstructure in the paper.First of all, the factors which influence the thermal barrier effect and the relationship between the factors and heat resistance were analyzed. Then, the paper gave the mathematical model of the effect of thermal conductivity, coating thickness, environment temperature difference, and heat exchange coefficient on thermal barrier effect. The curves of the relationships were provided depending on the mathematical model.Secondly, the influence of thermal conductivity on thermal barrier effect was investigated adequately. The measures for reducing thermal conductivity were shown in the thesis through the analysis of the mathematical model of thermal conductivity, including: addition of dopant atoms, increasing porosity and minishing coating thickness.At the last, based on the heat transfer theory, the paper provided the thermal field of ZW-100 coatings separately using analytic method and finite element method. At the same time, the thermal barrier effect was computed in the paper. Then the rules of the variety of thermal barrier effect in different compositions and different coating thickness were investigated using ANSYS.Computing and simulation of the thermal barrier effect of ZW-100 coatings and other coatings in different boundary conditions and inner compositions using finite element method and ANSYS were shown in the paper. At the last, the paper verified the rules of the variety of thermal barrier effect by experimentation and simulation.