Study on pyrolysis and laser ablation behavior of polycarbosilane based composite coatings on Ni-based alloy

For the development of protective coating for kilowatt-level lasers, this paper proposes the idea of recombining PCS reflective/ablative coating on the surface of traditional yttrium partially stabilized zirconia (YSZ) thermal insulation coating. NiCrAlY/YSZ thermal insulation coating (YSZ) and NiCrAlY/YSZ/PCS-Y2O3 thermal insulation/reflection-ablative coating (YPY) were prepared on the surface of Ni-based alloy by slurry method combined with atmospheric plasma spray (APS). The laser ablation resistance of YPY coating on 1.07 & mu;m YAG laser with different energy density was systematically studied and compared with that of YSZ coating, based on the study of the effect of Y2O3 addition on the pyrolysis behavior of PCS. The results showed that YPY coating had better laser protection effect than YSZ coating when the laser power density was less than 1687 W/cm2 and the ablation time was 2 s, which was directly related to the high reflectivity of YPY coating and the laser energy consumed by PCS pyrolysis. In addition, SiO2, SiC and Y2SiO5 phases generated during laser ablation provided further protection. This work is expected to provide references for the design of new laser-resistant composite coatings.