摘要Silicon-alloyed isotropic pyrolytic carbon (Si-IPyC) was prepared by steady-state fluidized bed chemical vapor deposition (SFBCVD). The effects of deposition temperature and propane concentration on the microstructure and deposition process of Si-IPyC were investigated using X-ray diffraction (XRD), X-ray energy dispersive spectrometer (EDS) and scanning electron microscope (SEM). The results show that the Si-IPyC with different silicon content is composed of both spherical granular and laminar structures, and silicon element is uniformly dispersed in pyrolytic carbon in the form of β-SiC. The deposition temperature and propane concentration have a great influence on the microstructure of Si-IPyC, with the increase of deposition temperature or propane concentration, the laminar structure in Si-IPyC decreases gradually, spherical granular morphology becomes increasingly obvious and the density decreases with the deposition model changing from surficial growth mechanism to gaseous nucleation mechanism. For getting a faster average coating rate, deposition temperature and propane concentration should not be too high.
Abstract：Silicon-alloyed isotropic pyrolytic carbon (Si-IPyC) was prepared by steady-state fluidized bed chemical vapor deposition (SFBCVD). The effects of deposition temperature and propane concentration on the microstructure and deposition process of Si-IPyC were investigated using X-ray diffraction (XRD), X-ray energy dispersive spectrometer (EDS) and scanning electron microscope (SEM). The results show that the Si-IPyC with different silicon content is composed of both spherical granular and laminar structures, and silicon element is uniformly dispersed in pyrolytic carbon in the form of β-SiC. The deposition temperature and propane concentration have a great influence on the microstructure of Si-IPyC, with the increase of deposition temperature or propane concentration, the laminar structure in Si-IPyC decreases gradually, spherical granular morphology becomes increasingly obvious and the density decreases with the deposition model changing from surficial growth mechanism to gaseous nucleation mechanism. For getting a faster average coating rate, deposition temperature and propane concentration should not be too high.
ZHANG Jian-hui, LIU Gang, ZHENG Yan-zhen. Silicon-alloyed Isotropic Pyrolytic Carbon Prepared by Steady-state Fluidized Bed Chemical Vapor Deposition[J]. 中国生物医学工程学报(英文版）, 2021, 30(2): 58-68.
ZHANG Jian-hui, LIU Gang, ZHENG Yan-zhen. Silicon-alloyed Isotropic Pyrolytic Carbon Prepared by Steady-state Fluidized Bed Chemical Vapor Deposition. Chinese Journal of Biomedical Engineering, 2021, 30(2): 58-68.
[1] Agnès O.Pyrocarbons[J]. Carbon, 2002, 40(1): 7-24. [2] Wu JF, Bai S, Liu SH, et al.Fabrication and characterization of large isotropic pyrolytic carbons[J]. New Carbon Materials, 2006, 21(2): 119-124. [3] Li X, Wu JF, Bai S.Fabrication and microstructure of boron-doped isotropic pyrolytic carbon[J]. Carbon, 2012, 50(12): 4705-4710. [4] Li JQ, Man RL, Xie ZY, et al.Preparation of bulk isotropic pyrocarbons by micro-positive CVD[J]. Journal of Central South University (Science and Technology), 2011, 42(3): 600-604. [5] López-Honorato E, Meadows PJ, Xiao P, et al.Structure and mechanical properties of pyrolytic carbon produced by fluidized bed chemical vapor deposition[J]. Nuclear Engineering and Design, 2008, 238(11): 3121-3128. [6] Chambers J.Prosthetic heart valves[J]. International Journal of Clinical Practice, 2014, 68(10): 1227-1230. [7] Ahmad KA, Ahmad FA, Balendu CV, et al.Prosthetic heart valves: types and echocardiographic evaluation[J]. International Journal of Cardiology, 2007, 122(2): 99-110. [8] Zhang JH, Sun HB, Wang GM, et al.Microstructure of silicon-alloyed pyrocarbon for mechanical heart valves[J]. Chinese Journal of Biomedical Engineering, 2011, 30(5): 757-761. [9] Zhang JH, Xia WL.Effects of deposition conditions on microstructures of low temperature isotropic pyrocarbon[J]. Chinese Journal of Nonferrous Metals, 2015, 25(1): 165-170. [10] Hu ZJ, Zhang WG, Hüttinger KJ, et al.Influence of pressure, temperature and surface area/volume ratio on the texture of pyrolytic carbon deposited from methane[J]. Carbon, 2003, 41(4): 749-758. [11] Pauw VD, Collin A, Send W, et al.Deposition rates during the early stages of pyrolytic carbon deposition in a hot-wall reactor and the development of texture[J]. Carbon, 2006, 44(14): 3091-3101. [12] Sun HC, Li SK, Yu XD, et al.Research on texture and mechanical performance of high-purity CVD tungsten[J]. Rare Metal Materials and Engineering, 2010, 39(8): 1415-1418. [13] Xu J, Chen WX, Zhang HZ.Composition contrast in high resolution secondary electron image[J]. Journal of Chinese Electron Microscopy Society, 1997, 16(1): 1-5. [14] Zhang WG.Chemical vapor deposition-from the hydrocarbon gas to solid carbon[M]. Beijing: Science Press, 2007: 222-227. [15] López-Honorato E, Meadows PJ, Xiao P.Fluidized bed chemical vapor deposition of pyrolytic carbon-I. Effect of deposition conditions on microstructure[J]. Carbon, 2009, 47(2): 396-410. [16] Wei J, Zhang JH.Analysis of interfacial adhesive strength of pyrolytic carbon-graphite for artificial mechanical heart valves[J]. Surface Technology, 2014, 43(6): 37-42. [17] Xie ZY, Huang QZ, Shu ZA, et al.Preparation of C/C composites by CVI with multi-factor coupling physical fields and deposition mechanism[J]. Journal of Inorganic Materials, 2005, 20(5): 1201-1207. [18] Kaae JL.The mechanism of the deposition of pyrolytic carbon[J]. Carbon, 1985, 23(6): 665-673. [19] Je JH, Lee JY.How is pyrolytic carbon formed? Transmission eletron micrographs which can explain the change of its density with deposition temperature[J]. Carbon, 1984, 22(3): 317-319. [20] Li KZ, He YG, Li HJ, et al.Deposition model and microstructure of low temperature pyrocarbon produced by chemical vapor deposition[J]. New Carbon Materials, 2012, 27(2): 81-86. [21] Xu W, Zhang ZW, Bai RC, et al.Kinetic model of gas-phase reactions in the chemical vapor deposition of propane[J]. New Carbon Materials, 2014, 29(1): 67-77. [22] Xiao P, Xu YD, Huang BY.Effects of deposition conditions on deposition thermodynamics and morphology of CVD-SiC[J].Journal of Inorganic Materials, 2002, 17(4): 877-881.
