Abstract:As the thrust-to-weight ratio of advanced aero-engines continues to increase, the turbine inlet temperature is also climbing, which makes the intensity of infrared radiation from fighter aircraft also increase dramatically. For the new generation of fighter aircraft, infrared stealth has been a problem that has to be considered. In order to meet the needs of the high temperature environment, the design of high temperature parts of the coating material generally use high temperature low thermal conductivity ceramic materials as the surface layer, and modern surface engineering technology in the target surface coating a layer of high temperature infrared low emissivity coating to reduce the target surface emissivity to achieve infrared stealth. The technical route of plasma spraying thermal barrier layer - arc ion plating metal layer - plating infrared stealth functional layer can effectively combine the two. Using plasma spraying-physical vapour deposition (PS-PVD) technology and atmospheric plasma spraying (APS) technology, a 7YSZ ceramic layer is prepared on the DZ40M high temperature alloy substrate, and then an Al layer is prepared by arc ion plating technology to improve the surface conductivity for plating, and at the same time, the nature of Al is borrowed to make the overall bonding strength of the coating increase, and finally a Pt metal layer is prepared by electroplating. The surface and cross-section of the coatings were analysed by field emission scanning electron microscopy (FESEM), X-ray diffractometer (XRD) and energy spectrometry (ES), and the infrared emissivity and bonding strength of the composite coatings were tested. The results show that the composite coating can still maintain a good bonding strength while keeping a low IR emissivity through the connection of Al metal layers of suitable thickness.
