Polymer-derived ceramics(PDCs)method opens up new possibilities for the preparation of novel multi-phase ceramic nanocomposites owing to the molecular design of the precursors at the nanoscale level.In the current wor...Polymer-derived ceramics(PDCs)method opens up new possibilities for the preparation of novel multi-phase ceramic nanocomposites owing to the molecular design of the precursors at the nanoscale level.In the current work,ZrC coatings incorporated with polymer-derived ceramic microspheres(CMS),SiH-fOC_CMS,were deposited to enhance the ablation resistance by supersonic atmosphere plasma spraying.Upon 10.0 MW·m^(-2) plasma ablation at above 3000℃,the linear ablation rate of ZrC-SiHfOC_CMS coat-ing was reduced to 0.20μm·s^(-1),62%lower than that of the pristine ZrC coating.The improvement was ascribed to the presentence of viscous SiO_(2)/HfO_(2) molten mixed phase,rather than HfSiO4,which can ef-fectively seal pinholes and cracks.Moreover,the in-situ generated crystalline SiO_(2) had a lower oxygen diffusion rate than amorphous SiO_(2),meanwhile,m-HfO_(2) could improve the stability of SiO_(2) glassy film,thus further enhancing the ablation resistance.展开更多
基金supported by the National Key R&D Program of China(No.N2022YFB3708600)the National Natural Science Foundation of China(Nos.52101098 and 52061135102)+1 种基金the Fund of Key Laboratory of National Defense Science and Technol-ogy(No.WDZC20235250505)The authors also thank the Analyti-cal&Testing Center of Northwestern Polytechnical University(No.2022T019)for the characterization.
文摘Polymer-derived ceramics(PDCs)method opens up new possibilities for the preparation of novel multi-phase ceramic nanocomposites owing to the molecular design of the precursors at the nanoscale level.In the current work,ZrC coatings incorporated with polymer-derived ceramic microspheres(CMS),SiH-fOC_CMS,were deposited to enhance the ablation resistance by supersonic atmosphere plasma spraying.Upon 10.0 MW·m^(-2) plasma ablation at above 3000℃,the linear ablation rate of ZrC-SiHfOC_CMS coat-ing was reduced to 0.20μm·s^(-1),62%lower than that of the pristine ZrC coating.The improvement was ascribed to the presentence of viscous SiO_(2)/HfO_(2) molten mixed phase,rather than HfSiO4,which can ef-fectively seal pinholes and cracks.Moreover,the in-situ generated crystalline SiO_(2) had a lower oxygen diffusion rate than amorphous SiO_(2),meanwhile,m-HfO_(2) could improve the stability of SiO_(2) glassy film,thus further enhancing the ablation resistance.
