(中南大學(xué) 粉末冶金國(guó)家重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083)
摘 要: 采用化學(xué)氣相反應(yīng)法在C/C復(fù)合材料表面制備抗氧化SiC涂層，借助X射線衍射儀、掃描電鏡及能譜等分析手段，研究涂層的結(jié)構(gòu)；通過(guò)氧乙炔焰燒蝕試驗(yàn)考察SiC涂層對(duì)C/C復(fù)合材料高溫耐燒蝕性能影響。結(jié)果表明：SiC涂層可明顯提高C/C復(fù)合材料的高溫短時(shí)耐燒蝕性能，經(jīng)過(guò)20 s的高溫氧乙炔焰燒蝕后，C/C復(fù)合材料試樣的線燒蝕率和質(zhì)量燒蝕率分別為13 μm/s和6.6 mg/s，SiC涂層試樣的線燒蝕率和質(zhì)量燒蝕率分別為22 μm/s和0.5 mg/s；在燒蝕中心區(qū)，涂層試樣的燒蝕以升華分解為主，同時(shí)還伴有氧化燒蝕和微區(qū)機(jī)械剝蝕；在燒蝕過(guò)渡區(qū)，涂層的燒蝕機(jī)制以熱氧化和燃?xì)鉀_刷為主；而在燒蝕邊緣區(qū)，涂層的燒蝕則主要表現(xiàn)為弱氧化燒蝕。
關(guān)鍵字: C/C復(fù)合材料；抗氧化涂層；SiC；氧乙炔焰燒蝕
C/C composites under oxyacetylene torch flame
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:The anti-oxidation SiC coatings were prepared on C/C composites by the chemical vapor reaction (CVR) method. The structure of the coatings was studied by XRD, SEM and EDS analysis, and the effect of SiC coatings on ablation resistance of C/C composites was investigated by oxyacetylene torch flame test. The results show that the prepared SiC coatings can effectively improve the ablation resistance of C/C composites in short time ablation. After 20s ablation by oxyacetylene flame, the linear ablation rate and mass ablation rate of C/C composites are 13 μm/s and 6.6 mg/s, respectively while those of SiC coated C/C composites are 22 μm/s and 0.5 mg/s, respectively. In the ablation center, the ablation mechanism of the coated sample is sublimation and decomposition, combined with thermo-oxidation and mechanical denudation. In the transitional field, the ablation mechanism of the coating is controlled by thermo-oxidation and scouring. And in the ablation rim, the coating exhibits slight oxidation behavior.
Key words: C/C composites; anti-oxidation coating; SiC; oxyacetylene torch flame ablation
