Long-life ablation resistance ZrB2-SiC-TiSi2 ceramic coating for SiC coated C/C composites under oxidizing environments up to 2200 K

摘要

To improve the ablation resistance of carbon/carbon (C/C) composites at temperature about 2200 K, a ZrB2-SiC-TiSi2 ultra-high temperature ceramic coating was prepared by supersonic atmosphere plasma spraying on SiC coated C/C composites. The ZrB2-SiC-TiSi2 coating could protect C/C composites for more than 240 s under heat flux of 2400 kW/m(2). The maximum surface temperature of the sample can reach to 2230 K. In addition, the mass and linear ablation rates of the coated samples after ablation for 240 s are only (0.314 +/- 0.065) x 10(-3) g/s and (0.221 +/- 0.026) x 10(-3) mm/s, respectively. The ZrB2-SiC-TiSi2 coating was converted into three layers after ablation: an outer layer, a particle-stacking layer, and a molten filled layer. The production of ZrTiO4, acting as sintering additive, could promote the sintering of ZrO2 and fill the pores, which effectively improved the ablation resistance of ZrB2-SiC-TiSi2 coating. (C) 2020 Elsevier B.V. All rights reserved.