| Thermal barrier coatings (TBCs) is a heat insulation system composed of a ceramic top coat and a metallic bond coat which bond the top coat and the superalloy substrate together. With excellent high temperature capability, corrosion resistance and low thermal conductivity of ceramic, TBCs were used to elevate the service temperature of metal parts, prolong the service life of hot sections, and improve the work efficiency of engines. Since the temperature reduction across TBCs directly impacts the engines performance and reliability, it is critical to accurately determinate the thermal insulation effect of TBCs for the engines designing and for the research to decrease the thermal conductivity of TBCs. Thus, thermal insulation effect becomes one of the most critical issue for TBCs research. The determination of thermal insulation effect was traditionally conducted in operating the real assembled engines. This on-line method has many disadvantages such as long testing time, energy consumption, complicated procedure and high risk. It is necessary and emergent to establish a off-line method and standard to evaluate the thermal insulation effect of TBCs. At present, the thermal conductivity of Y203 partially stabilized zirconia (YSZ)coat deposited by electron beam physical vapor deposition technology (EB-PVD) is relatively higher, which can not meet the requirements of the advanced high-powered aero engines. So developing TBCs with new type of structure and new materials became one of the key research field in the design of next generation aero engines. This paper is aimed at the issues and requirements mentioned above.Laser flash method and DSC were used to investegate the thermal properties of EB-PVD TBCs. combined with coat thickness, cooling air flux and service environment temperature, the thermal insulation effect was calculated and simulated, and was compared with the real tested temperature reduction. At the same time, the effects of temperature, heating history, dimension and laser penetrability induced by zirconia's semi-transparence on the thermal diffusion coefficient of TBCs were studied. The way to solve the laser penetrability problem is still being explored. Results show that simulated values of thermal insulation effect agreed well with the real tested ones. With the elevation of temperature, thermal diffusion coefficient decreased at beginnig and then increased again. But the extent of variety is not great in the whole testing temperature range. Vertical microcrack originated in the process of heat treatment resulted in a higher thermal diffusion coefficient. The laser penetrability problem existed in the tests was effectively overcome by multiple shelter layer of Au and gluey graphite.The influence of microstructure, material properties on the thermal insulation property of TBCs were analyzed. Micro-laminated YSZ TBCs were deposited on DZ125 superalloy by using incontinuous EB-PVD technology. The thermal insulation and the oxidation resistance properties of the coating were also investigated. It is showed micro-laminate structure brought 20%~30% thermal diffusion coefficient reduction and it's cyclic oxidation life is comparable with normal structured TBCs as the ratio of layer number to thickness was properly selected.La2Zr2O7 ingots were synthesized by air sinter method. As TBCs top coating, La2Zr2O7 coatings of this material were deposited by EB-PVD and the thermophysical and oxidation resistance properties were studied. Thermal conductivity value of the coating is measured to be 0.796W/(m·K)～0.985W/(m·K), far lower than the normal YSZ EB-PVD coating. The weight gain rate of this coating upon isothermal oxidation is lower than YSZ TBCs and its sintering resistance property is improved greatly. With relatively low thermal expansion coefficient, La2Zr2O7 coating need further improve its thermal cyclic life.
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