(大連理工大學(xué)工業(yè)裝備結(jié)構(gòu)分析國家重點(diǎn)實(shí)驗(yàn)室，航空航天學(xué)院，大連116024)
摘 要: 以ZrSi2、B4C和炭黑為原料，采取硼-碳熱還原法，分別在1000、1200及1400 ℃溫度下反應(yīng)，合成納米SiC-ZrB2復(fù)合陶瓷粉體。采用掃描電鏡(SEM)、能譜儀(EDS)及X射線衍射(XRD)對復(fù)合粉體的顯微形貌、物相組成及晶粒尺寸進(jìn)行表征；利用熱力學(xué)計(jì)算分析合成過程的反應(yīng)機(jī)理。結(jié)果表明：當(dāng)溫度為1000 ℃時，硼-碳熱還原反應(yīng)并不徹底，粉體中仍存在ZrSi2未參與反應(yīng)；當(dāng)溫度升高到1200 ℃時，反應(yīng)可完全進(jìn)行，合成的納米SiC-ZrB2復(fù)合陶瓷粉體顆粒分布均勻，SiC粒子尺寸約為40 nm，ZrB2顆粒尺寸約為300 nm；當(dāng)溫度進(jìn)一步升高到1400 ℃后，SiC-ZrB2復(fù)合粉體中晶粒長大明顯，SiC顆粒附著在ZrB2顆粒表面，并且復(fù)合粉體出現(xiàn)燒結(jié)引起的密實(shí)現(xiàn)象。
關(guān)鍵字: ZrB2；SiC；硼-碳熱還原法；復(fù)合粉體
（State Key Laboratory of Structural Analyses for Industrial Equipment, Dalian University of Technology,
Dalian 116024, China）
Abstract:Nano-sized SiC-ZrB2 ceramic powder mixture was synthesized at temperatures of 1000, 1200 and 1400 ℃by boro-carbothermal reduction method with ZrSi2, B4C and C as raw materials. The morphology, phase composition and crystallite size of the synthesized powder mixtures were characterized by scanning electron microscopy (SEM) with energy dispersive spectrometer (EDS) and X-ray diffractometry (XRD). Thermo kinetics calculation was also carried out to analyze the synthesis mechanism. The results show that the synthesis reaction can not be completed thoroughly, and unreacted ZrSi2 can be detected in the powder mixtures. At 1200 ℃, the reaction occurs completely, and both produced particles, SiC and ZrB2, distribute homogeneously in the powder mixtures. The mean sizes of SiC and ZrB2 particles in the powder mixture synthesized at 1200 ℃ are 40 nm and 300 nm, respectively. At 1400 ℃, the agglomeration phenomenon of the ceramic powder mixture appears due to the sintering at high temperature.
Key words: ZrB2; SiC; boro-carbothermal reduction; ceramic powder mixture
