石墨基体表面原位生成的TiB_2-C涂层结构研究（英文）

The structure of an in-situ formed titanium-boron-carbon coating on a graphite substrate

通过将二硼化钛置于石墨基体表面并加热至共熔温度以上,在石墨基体表面原位生成了TiB_2-C涂层。所形成的涂层表面为石墨,内部为TiB_2-C合金。由于二硼化钛与石墨间热膨胀系数的不同,致使涂层表面的石墨有许多褶皱;内部的TiB_2-C合金为三维贯穿结构,其中的石墨组分d_(002)值为0.335 6 nm,接近于单晶石墨的0.335 4 nm,拉曼光谱及XPS结果表明石墨晶格中有B原子的掺杂。热震试验表明此种原位生成的涂层与基体具有良好的结合力,该方法有望成为碳材料表面制备热防护涂层的新途径。

A titanium-boron-carbon coating was fabricated on a graphite substrate by heating TiB2powder on a graphite surface above the eutectic temperature.The coating consisted of a pure graphite layer on the outer surface and a TiB2-C alloy layer inside.The graphite layer had many wrinkles due to the difference in the thermal expansion coefficients of TiB2and graphite.The TiB2-C alloy layer had a continuous three-dimensional interpenetrating network microstructure.The d002value of the graphite in the alloy layer was0.3356nm,which was quite close to that of single crystal graphite(0.3354nm).Raman and X-ray photoelectron spectroscopy indicated that the graphite in both layers was doped substitutionally with boron atoms.A water quench thermal shock test verified a high adhesion strength between the coating and the substrate.This method is promising for the fabrication of thermal barrier coatings on carbon materials