Russian Journal of Inorganic Chemistry ( IF 2.1 ) Pub Date : 2021-09-21 , DOI: 10.1134/s003602362109014x E. P. Simonenko 1 , N. P. Simonenko 1 , I. A. Nagornov 1, 2 , V. G. Sevastyanov 1 , N. T. Kuznetsov 1 , A. F. Kolesnikov 3 , A. V. Chaplygin 3 , A. S. Lysenkov 4
Abstract
Oxidation under exposure to a supersonic dissociated air jet (with heat fluxes in the range 363–779 W/cm2, total exposure time: 2000 s) was studied for HfB2–30 vol % SiC ultra-high-temperature ceramics (UHTC) doped with a lowered amount (1 vol %) of reduced graphene oxide (GO). Doping the ceramics with a relatively low amount of reduced GO (1 vol %) did not prevent a dramatic increase in the average surface temperature to 2300–2400°С. However, the existence time of surface temperatures below 1800–1850°С increased considerably, probably due to an increase in the thermal conductivity of the ceramics. The ablation rate of the material was determined as 6.5 × 10–4 g/(cm2 min), which is intermediate between the respective values for HfB2–SiC ceramics and the ceramics doped by 2 vol % graphene. The microstructure features and elemental composition of the oxidized surface and chips of the material were studied. The structure and thickness of the oxidized near-surface region were determined.
中文翻译:
用石墨烯 (1 vol %) 改性 HfB2–30% SiC UHTC 及其对超音速空气喷射行为的影响
摘要
针对 HfB 2 –30 vol % SiC 超高温陶瓷 (UHTC)研究了暴露于超音速分解空气射流(热通量范围为 363–779 W/cm 2,总暴露时间:2000 s)下的氧化掺杂少量(1 vol%)的还原氧化石墨烯(GO)。用相对少量的还原 GO(1 体积%)掺杂陶瓷并不能阻止平均表面温度显着增加到 2300-2400°С。然而,表面温度低于 1800-1850°С 的存在时间显着增加,这可能是由于陶瓷的热导率增加。材料的烧蚀速率确定为 6.5 × 10 –4 g/(cm 2 min),介于 HfB 的各个值之间2 – SiC 陶瓷和掺杂 2 vol% 石墨烯的陶瓷。研究了材料氧化表面和切屑的微观结构特征和元素组成。确定了氧化近表面区域的结构和厚度。