(中南大學(xué) 粉末冶金國家重點實驗室，長沙 410083)
摘 要: 采用ZrCl4-CH4-H2-Ar體系在C/C材料基體上進(jìn)行常壓化學(xué)氣相沉積(APCVD)制備碳化鋯(ZrC)涂層。通過X射線衍射技術(shù)(XRD)和掃描電鏡(SEM)對不同H2濃度下制備的ZrC涂層進(jìn)行分析。對H2在沉積過程中的作用機(jī)制進(jìn)行了討論。結(jié)果表明：H2濃度對涂層的相組成、晶體的擇優(yōu)取向和結(jié)構(gòu)形態(tài)有重要影響；無H2或H2濃度較低時，涂層含有大量的熱解碳，由ZrC和碳兩相組成，涂層呈多孔顆粒狀；當(dāng)H2濃度(體積分?jǐn)?shù))增加到30%以上時，涂層的相成分變?yōu)閱我籞rC相；當(dāng)H2的濃度增加到90%時，ZrC晶體取向由(111)、(200)轉(zhuǎn)變?yōu)閺?qiáng)烈的(220)擇優(yōu)取向，晶粒形貌變?yōu)榧{米針狀。
關(guān)鍵字: ZrC涂層；常壓化學(xué)氣相沉積；H2濃度；擇優(yōu)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
