Fabrication And Performance Of Thermal Shock Resistance For Thermal Barrier Coatings By Electron Beam Physical Vapor Deposition

The thermal barrier coatings (TBCs) is one of the key technologies to develop high performance aero-engines, widely used in combustion and engine blades of aviation engines.It increase the gas temperature and engine thrust-weight ratio by reduce the surface temperature of the superalloy by substrate to reduce the amount of cooling gas engine. The current study is develop new technology and new materials development. But it is shtortage that effects of process parameters on the microstructure and thermal shock resistance of the coating.Its structure has vary big influence to the performance.So,its performance has great change by improve structure.In this dissertation, it produce different Thermal Barrier Coatings at different process parameters,and study its Thermal Shock Resistance.Multiple sets of different process parameters of TBCs were prepared on the NI base Superalloy by using Electron beam evaporation and resistive evaporation composite coating system. Based on the material characteristics, coatings with different surface characteristic were prepared by altering the Beam Current and Substrate Temperature. Surface morphology and chemical composition were obtained by using measurement methods such as SEM(Scanning Electron Microscope) and EDS (Energy Dispersive Spectrometer). Through the discussion of SEM and XRD image,surface morphology and chemical composition under different perpare parameters were obtained. Based on the discussion and analysis of the test results, the influence rules of surface morphology, mechanical preperties on the coating with different parameters were obtained.It tested performance of thermal shock resistance for the thermal barrier coatings. Cooled to room temperature in air for10min after maintained at1100℃for50min. Repeat this Process. The first peeling sample is300MA, the finally peeling sample is350MA.at same number of cycles.Summary,350MA sample has the best thermal shock resistance. At the last, it study the failure mechanism of thermal barrier coatings. In conclusion:the300MA coating’s atoms is very dense. In the Surface, it come out many microcracks after thermal shock test; the400MA coating’s atoms is very relax. In the Surface, it come out many micropores after thermal shock test;Both have great useful to can help transport of oxygen. Analysis section of coating damage morphology, it come to a conclusion that Cumulative thermal stress in the coating flaking caused by the growth of TGO...