Novel anti-oxidation coating prepared by polymer-derived ceramic for harsh environments up to 1200 °C

Environmental barrier coatings (EBCs) are protective barriers that could prevent internal materials from oxygen and harmful agents. However, the combination between EBCs and polymer-derived ceramics (PDCs) is relatively hard but essential. In this work, an anti-oxidation coating based on PDCs is fabricated on target SiBCN ceramics by spraying. The coating reveals a uniform and continuous structure with an approximate thickness of 11.7 μm. Experiments and characterization such as oxidation, thermal shock, scratch, and electrical resistance tests were carried out to investigate the performance of coating. The results show that during the high-temperature oxidation process, the coating surface undergoes a molten phase transformation that effectively seals pores and cracks, preventing oxygen diffusion into the ceramic interior. Moreover, the coating can withstand 20 thermal shocks without failure, and firmly adheres to the substrate even after prolonged oxidation and repeated thermal cycling. Comparative analysis of temperature-resistance results demonstrates the efficacy of the coatings in protecting against oxidation up to 1200 °C. The developed PDC-EBCs here exhibit remarkable resistance to oxidation and thermal shock, along with high insulation resistivity. This strategy offers a straightforward and efficient solution for protecting electronic materials in harsh environments.