Effect of multicomponent alloy coating on high frequency plasma ablation of diamond films

Abstract

Diamond films have excellent transmittance from ultraviolet to far infrared, as well as excellent resistance to laser damage, mechanics, dust, rain, and other characteristics. Therefore, diamond films are used in aircraft infrared windows and supersonic flight missile hoods. The surface of supersonic aircraft can cause plasma ablation under intense aerodynamic heating. High temperature gas on the surface has strong vibration, dissociation, and ionization, resulting in many defects in the optical windows and protective covers on the outer surface of the aircraft, which may lead to deterioration of optical performance. In this thesis, microwave plasma chemical vapor deposition (MPCVD) method was used to synthesize high-quality diamond films using high-purity gas, while using magnetron sputtering to deposit multicomponent alloy coating as a protective layer to study the high-frequency plasma ablation effect of diamond films. Raman spectroscopy, visible-infrared transmittance spectra and field emission scanning electron microscopy was used to analyze the spectrum of diamond films before and after high-frequency plasma ablation. It was found that the multicomponent alloy coatings have good ablation resistance and high transmittance in the 1~4μm wavelength range, while the carbon and alloying components remain on the film surface. This research contributes to promoting the supersonic flight application of diamond films and provides data reference for the design of aircraft outer surface materials.