A SiC coating was prepared on carbon/carbon (C/C) composites by a two-step technique of pack cementation and CVD processes to prevent these composites from oxidation. SEM, EDS and XRD were applied to analyze the surface and cross-section morphologies, element distribution and phase composition of the coating, respectively. The results show that a transitional layer with gradient distribution of Si and C content is formed between the SiC coating obtained by pack cementation process and C/C substrate, and the compact coating prepared by CVD process effectively fills the pores of the coating by pack cementation. The coating made by the two-step technique exhibits excellent oxidation protective ability. The weight loss percentage of the coated C/C composites is only 2.01% after oxidation in air at 1500℃ for 60h. The weight loss of C/C composites is primarily due to the reaction of C/C and oxygen diffusing through the microcracks in the coating during the thermal cycle between 1500℃ and room temperature.
WANG Biao
,
LI Ke-Zhi
,
LI He-Jun
,
FU Qian-Gang
,
WANG Xiang
,
LAN Feng-Tao
. SiC Coating Prepared by a Two-step Technique of Pack Cementation and CVD on Carbon/Carbon Composites[J]. Journal of Inorganic Materials, 2007
, 22(4)
: 737
-741
.
DOI: 10.3724/SP.J.1077.2007.00737
[1] 李贺军. 新型炭材料, 2001, 16 (2): 79--80.
[2] 孙万昌, 李贺军, 白瑞成, 等(SUN Wan-Chang, et al). 无机 材料学报(Journal of Inorganic Materials), 2005, 20 (3): 671--676.
[3] 黄剑锋, 李贺军, 熊信柏, 等. 新型炭材料, 2005, 20 (4): 373--379.
[4] Fu Q G, Li H J, Shi X H, et al. Scri. Mater, 2005, 52 (9): 923--927.
[5] Huang J F, Zeng X R, Li H J, et al. Carbon, 2004, 42 (8-9): 1517--1521.
[6] 牛晓滨, 廖源, 常超, 等(NIU Xiao-Bin, et al). 无机材料学报(Journal of Inorganic Materials), 2004, 19 (2): 397--402.
[7] Huang J F, Li H J, Zeng X R, et al. Carbon, 2004, 42 (11): 2356--2359.
[8] Lamouroux F, Bourrat X, Naslain R. Carbon, 1995, 33 (4): 525--535.
[9] 传秀云, 李贺军, 曾燮榕, 等. 新型炭材料, 1999, 14 (3): 63--68.