Regulation And Application Of Particle Interface Of Plasma Sprayed Thermal Barrier Coatings

With the development of the level of technology and the needs of society,aerospace engines and gas turbine high-temperature components have increasingly high requirements for the insulation capacity of thermal barrier coatings（TBCs）.Therefore,it is crucial to improve the thermal barrier coating insulation capacity and service life for the development of China’s aerospace industry.Thermal barrier coatings prepared by Atmospheric Plasma Spraying（APS）technology are widely used in high temperature components of aerospace engines and gas turbines.TBCs are functional coatings with multi-layer structure and thermal protection,which have low thermal conductivity and excellent thermal insulation properties,and the thermal barrier coatings prepared by APS have a typical laminar structure.In order to improve the thermal and mechanical properties of APS TBC,this paper investigates a new type of interlayer interface bonded TBC by changing the interlayer particle interface bonding angle in the process of preparing thermal barrier coating by plasma spraying using the characteristic of APS TBC with a laminar structure,and combines experiments and numerical simulations to study the evolution of its thermal and mechanical properties and optimize the interlayer The evolution of the thermal and mechanical properties and the optimization of the interlayer bonding angle were investigated by combining experimental and numerical simulations.（1）The TBC with different particle interface bonding angles of 0°,15°,30°,45°,60°,75°and 90°were prepared by APS in co-directional and staggered rotation.The physical phase analysis of ceramic layer powder and TBC ceramic layer by X-ray diffractometer（XRD）showed that there was basically no difference in their physical phases,which were both monoclinic and tetragonal phase zirconia.Microstructure analysis of TBC by scanning microscopy（SEM）revealed that the longitudinal cross-sectional pores of the interlayer particle interface bonding angle 90°TBC were more dense,with optimal interlayer bonding and minimal interlayer bonding area.（2）The thermal and mechanical properties of TBC with different particle interface bonding angles for co-directional and staggered rotations were investigated using laser flash method,Vickers hardness method,and indentation method.The thermal conductivity of the interlayer particle interface bonding angle of 90°TBC is the lowest at 1.609W/m·K.Compared with conventional plasma spraying TBC,the thermal conductivity is reduced by8.9%,the hardness is increased by 63.7%,and the fracture toughness is increased by 29.7%,which is conducive to improving the fracture damage resistance of TBC and laying the foundation for high thermal insulation and long life TBC.The fracture toughness of the staggered rotating interlayer particle interface bonding angle of 75°TBC was highest.（3）Solid Works software was used to model the thermal barrier coating with different particle interface bonding angles of 0°,15°,30°,45°,60°,75°and 90°for co-directional and staggered rotation.The thermal and mechanical simulations were performed using Ansys software to analyze the equivalent thermal conductivity of the TBC as well as its deformability by combining different particle interface models with co-directional and staggered rotations.The equivalent thermal conductivity of the interlayer particle interface bonding angle 90°TBC is the lowest at 0.834W/m·K.The ceramic layer of the staggered rotating particle interface bonding angle 75°TBC has the strongest resistance to deformation at 0.364×10^-10m.