(中南大学 粉末冶金国家重点实验室，长沙 410083)
摘 要: 采用ZrCl4-CH4-H2-Ar体系在C/C材料基体上进行常压化学气相沉积(APCVD)制备碳化锆(ZrC)涂层。通过X射线衍射技术(XRD)和扫描电镜(SEM)对不同H2浓度下制备的ZrC涂层进行分析。对H2在沉积过程中的作用机制进行了讨论。结果表明：H2浓度对涂层的相组成、晶体的择优取向和结构形态有重要影响；无H2或H2浓度较低时，涂层含有大量的热解碳，由ZrC和碳两相组成，涂层呈多孔颗粒状；当H2浓度(体积分数)增加到30%以上时，涂层的相成分变为单一ZrC相；当H2的浓度增加到90%时，ZrC晶体取向由(111)、(200)转变为强烈的(220)择优取向，晶粒形貌变为纳米针状。
关键字: ZrC涂层；常压化学气相沉积；H2浓度；择优取向
ZrC coating by APCVD
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:Zirconium carbide (ZrC) coatings were prepared on carbon-carbon composites substrates by means of atmospheric pressure chemical vapor deposition (APCVD). ZrCl4-CH4-H2-Ar system was used in this deposition process. And the effect of different hydrogen concentration on coating properties was studied by X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The mechanism of hydrogen in the deposition process was also studied. The results show that the coating phase composition, preferential growth and structure morphology change significantly as the hydrogen concentration increasing. With pure argon or less hydrogen, ZrC coating is porous, which is made up of ZrC and C two-phase, and is contained by lots of pyrocarbon. When the hydrogen concentration reaches more than 30%(volume fraction), there is only ZrC phase in the coating. When the hydrogen concentration reaches 90%, ZrC crystal preferential growth changes from (111) plane and (200) plane to intensive (220) plane, and the crystal morphology turns into nano-needle-like morphology.
Key words: ZrC coatings; atmospheric pressure chemical vapor deposition; H2 concentration; preferential growth
