TiB2/ZrB2-C自生复合材料涂层的制备与表征

Preparation and characterization of a TiB2/ZrB2-C eutectic coating

  • 摘要: 通过加热TiB2及ZrB2粉末与等静压炭块至共熔点以上的方法制备出新型炭/陶复合材料涂层TIB、ZRB-1与ZRB-2。结果表明,所制自生复合材料涂层的表层与内部结构明显不同,表层由B掺杂的高度有序石墨构成,内部由TiB2-C或ZrB2-ZrC-C合金组成。TIB、ZRB-1与ZRB-2涂层中石墨的d002值分别为0.3359、0.3360与0.3354 nm,接近或等于单晶石墨的d002值(0.3354 nm),表明高度有序石墨结构的形成。3种涂层内部石墨的拉曼光谱中D峰、D'峰明显,2D峰强度低及G峰向高波数偏移,这些特征是由石墨碳网格结构中B掺杂所致。此外,ZrB2粒径小有利于涂层表层应力的释放。

     

    Abstract: 74μm TiB2, and 74μm and 1μm ZrB2 powders were heated with isostatically pressed carbon blocks at 2550℃, which is above the eutectic temperature of TiB2-C and ZrB2-C, to form eutectic coatings, which are named TIB, ZRB-1 and ZRB-2, respectively. Results showed that the surface and the inner part of the coatings were different. The surface of the coatings was composed of B-doped highly ordered graphite, and the inner part was composed of TiB2-C or ZrB2-C alloy. The d002 values of graphite in samples TIB, ZRB-1 and ZRB-2 were 0.3359, 0.3360 and 0.3354 nm, respectively, which are almost the same as that of single crystal graphite(0.3354 nm), indicating the formation of highly ordered graphite. The features of the Raman spectra of these three coatings such as the appearance of D and D' bands, low intensity 2D bands and the shift of G bands to higher wave numbers are ascribed to B-doping in the graphene layers of the graphite. The small particle size of the ZrB2 powder favored the relaxation of the stress formed inside the surface of the coatings.

     

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