Abstract：SiC coatings were prepared on the surface and inside of porous low-density C/C composites by chemical vapor phase reaction using Si and SiO2 powders as raw materials. MoSi2 powder was used as raw materials to reactive infiltrate C/C composites and C/C composites with SiC interface layer to obtain MoSi2 modified C/C composites. The microstructure of the composites was investigated by scanning electron microscopy, X-ray diffraction and electron probe microanalysis. The bending strength of the material was tested by Instron 3369 mechanical testing machine. The results show that compared with the Si-Mo modified C/C composite prepared by MoSi2 direct infiltration, the SiC coating prepared before infiltration can effectively reduce the porosity of the SiC/C composite and obtain more compact Si-Mo modified C/C composite. The density of composites increases from 2.93 g/cm3 to 3.20 g/cm3, the open porosity decreases from 10.77% to 4.07%; the flexural strength increases from 87 MPa to 121 MPa. The content of SiC and MoSi2 in composites is higher. The composites exhibit pseudoplastic fracture behavior.
[1] WINDHORST T, BLOUNT G.Carbon-carbon composites: A summary of recent developments and applications[J]. Materials & Design, 1997, 18(1): 11-15. [2] LI J, LUO R.Study of the mechanical properties of carbon nanofiber reinforced carbon/carbon composites[J]. Composites Part A: Applied Science and Manufacturing, 2008, 39(11): 1700-1704. [3] LAMOUROUX F, BERTRAND S, PAILLER R, et al.Oxidation-resistant carbon-fiber-reinforced ceramic-matrix composites[J]. Composites Science and Technology, 1999, 59(7): 1073-1085. [4] 韩秀峰, 张立同, 成来飞, 等. 基体改性对碳纤维增韧碳化硅复合材料结构与性能的影响[J]. 硅酸盐学报, 2006, 34(7): 871-874. HAN Xiufeng, ZHANG Litong, CHENG Laifei, et al.Influence of matrix modification on microstructure and properties of carbon fiber reinforced silicon carbide composites[J]. Journal of The Chinese Ceramic Society, 2006, 34(7): 871-874. [5] PAUL A, VENUGOPAL A, BINNER S, et al.UHTC-carbon fibre composites[J]. Journal of the European Ceramic Society, 2013, 33(2): 423-432. [6] 李军, 杨鑫, 黄启忠, 等. 耐烧蚀超高温陶瓷改性C/C复合材料的研究进展[J]. 中国有色金属学报, 2015, 25(7): 1731-1743. LI Jun, YANG Xin, HUANG Qizhong, et al.Research progress of ultra-high temperature ceramic modified C/C composites for ablation resistance[J]. Chinese Journal of Nonferrous Metals, 2015, 25(7): 1731-1743. [7] TANG S, DENG J, LIU W, et al.Mechanical and ablation properties of 2D-carbon/carbon composites pre-infiltrated with a SiC filler[J]. Carbon, 2006, 44(14): 2877-2882. [8] ZHU Y, WANG S, CHEN H, et al.Fabrication and characterization of 3-D Cf/ZrC composites by low-temperature liquid metal infiltration[J]. Composites Part B: Engineering, 2014, 56: 756-761. [9] FAN X, YIN X, CAI Y, et al.Mechanical and electromagnetic interference shielding behavior of C/SiC composite containing Ti3SiC2[J]. Advanced Engineering Materials, 2017, 20(2): 1700590. [10] PI Huilong, FAN Shangwu, WANG Yiguang.C/SiC-ZrB2-ZrC composites fabricated by reactive melt infiltration with ZrSi2 alloy[J]. Ceramics International, 2012, 38(8): 6541-6548. [11] PETROVIC J J. Mechanical behavior of MoSi2 and MoSi2 composites[J]. Materials Science and Engineering A, 1995, 192/ 193: 31-37. [12] LIM C B, YANO T, ISEKI T.Microstructure and mechanical properties of RB-SiC/MoSi2 composite[J]. Journal of Materials Science, 1989, 24(11): 4144-4151. [13] TONG Y, BAI S, ZHANG H, et al.C/C-SiC composite prepared by Si-10Zr alloyed melt infiltration[J]. Ceramics International, 2012, 38(4): 3301-3307. [14] HILLIG W B.Melt infiltration approach to ceramic matrix composites[J]. Journal of the American Ceramic Society, 1988, 71(2): 96-99. [15] PENG L M, WANG J H, LI H, et al.Synthesis and mechanical properties of ternary molybdenum carbosilicide and its composite[J]. Journal of Materials Science, 2005, 40(9/10): 2705-2707. [16] GNESIN B A, GNESIN I B, NEKRASOV A N.The interaction of carbon with Mo5Si3 and W5Si3 silicides. Nowotny phase synthesis[J]. Intermetallics, 2013, 41(Complete): 82-95.
2019, Vol. 24 
