CVD-SiC阵列结构对ZrB_(2)/SiC涂层抗烧蚀性影响

Effect of CVD-SiC array structure on ablation resistance of ZrB_(2)/SiC coatings

采用飞秒激光在化学气相沉积(CVD)-SiC中间层表面制备不同尺寸的阵列,研究了阵列结构对ZrB_(2)/SiC涂层性能的影响。结果表明,随着激光刻蚀频次的增大,阵列结构的深度从30μm增大到150μm。采用氧乙炔烧蚀600 s,ZrB_(2)/SiC涂层烧蚀表面温度随CVD-SiC微结构深度增大而逐步降低,最低的表面温度达到1700℃,下降了约200℃。烧蚀中心区域的颜色从白色过渡到浅灰色。对于激光刻蚀频次为5的试样,在600 s的单次烧蚀后,质量烧蚀率和线性烧蚀率分别为-7.4×10^(-5)g/s和-13.3μm/s。阵列结构增大了ZrB_(2)/SiC涂层与CVD-SiC中间层的接触面积,从而增强了导热性能,减少了热积聚,进而改善了ZrB_(2)/SiC涂层的抗烧蚀性能。

Influence of array structure on the performance of ZrB_(2)/SiC coatings was studied by using femtosecond la⁃ser to prepare arrays with different sizes on the surface of the Chemical Vapor Deposition(CVD)-SiC interlayer.Re⁃sults showed that with the increase of laser etching frequency,the depth of the array structure increased from 30μm to 150μm.After 600 s of oxyacetylene combustion,the surface temperature of the ZrB_(2)/SiC coating decreased gradually with the increase of CVD-SiC microstructure depth,and the lowest surface temperature reached 1700℃,which de⁃creased by nearly 200℃.The color of the combustion center area transitioned from white to light gray.For the samples with an etching frequency of 5 times,after a single cycle of 600 s,the mass combustion rate and linear com⁃bustion rate were-7.4×10^(−5) g/s and-13.3μm/s respectively.The array structure increased the contact area be⁃tween the ZrB_(2)/SiC coating and the CVD-SiC interlayer,thereby increasing the thermal conductivity,reducing heat ac⁃cumulation,and ultimately enhancing the anti-combustion performance of the ZrB_(2)/SiC coating.