Carbon/carbon-polyimide composites were prepared by chemical vapor infiltration and vacuum-pressure impregnation curing process. Firstly, the carbon felt was deposited with pyrolytic carbon by chemical vapor infiltration method to prepare porous carbon/carbon materials with pyrolytic carbon contents of 7.33%(mass fraction, the same below), 14.55% and 22.00%, respectively. Then, through a specific impregnation curing process, the carbon/carbon-polyimide composites P1, P2 and P3 and the control group P0 without pyrolytic carbon were obtained in turn. Through SEM, linear expansion coefficient test and mechanical properties test, the effects of different pyrolytic carbon contents on the microstructure, average linear expansion coefficient and mechanical properties of carbon/carbon-polyimide composites were investigated. The results show that in the temperature range of 20-300℃, the XY-direction average linear expansion coefficients of P0, P1, P2 and P3 are between (0.67-0.79)×10-6℃-1, and the XY-direction average linear expansion coefficients of four groups are basically the same. The Z-direction average linear expansion coefficients of P1, P2 and P3 decrease by 41.6%, 41.8% and 24.1%, respectively compared with P0. Pyrolytic carbon significantly reduces the Z-direction average linear expansion coefficient of materials. The XY-direction compressive strengths of P0, P1, P2 and P3 are 243.91, 244.73, 216.65 MPa and 210.79 MPa, respectively, and the Z-direction compressive strengths are 269.22, 258.80, 246.68 MPa and 219.20 MPa, respectively. The compressive strength of P1 is equivalent to that of P0. The Z-direction bending strengths of P0, P1, P2 and P3 are 92.77, 77.11, 80.71 MPa and 86.06 MPa, respectively. Different pyrolytic carbon contents have different effects on the mechanical properties of materials. The lower pyrolytic carbon content can basically maintain compressive strength of materials, while the higher pyrolytic carbon content can basically maintain bending strength of materials.
YU G , WEI H Z , LI D Y , et al. Effect of heat treatment temperature on properties of carbon fiber reinforced polyimide composites[J]. Engineering Plastics Application, 2020, 48 (6): 62- 67.
2
YANG J , XIAO Q , LIN Z , et al. Growth of ultra-dense MoS2 nanosheets on carbon fibers to improve the mechanical and tribological properties of polyimide composites[J]. Friction, 2020, 9 (5): 13.
3
LV Y Q , PENG C Z . Improved interfacial properties of PI composites through graphene oxide and carbon nanotubes on carbon fiber surface[J]. Surface and Interface Analysis, 2018, 50 (6): 634- 639.
doi: 10.1002/sia.6448
4
宋俊涛. 碳纤维表面碳涂层的水热制备及机理研究[D]. 哈尔滨: 哈尔滨工业大学, 2018.
4
SONG J T. Hydrothermal preparation and mechanism of carbon coating on carbon fiber surface[D]. Harbin: Harbin Institute of Technology, 2018.
5
SHARMA S P , TING J M , VILAR R . Electron microscopy study of surface-treated carbon fiber for interface modification in composites[J]. Diamond and Related Materials, 2020, 109, 108021.
doi: 10.1016/j.diamond.2020.108021
SUN J F , ZHAO F , XING L X , et al. Modification of carbon fiber surface by pyrolysis deposition combined with PAMAM grafting[J]. Hi-Tech Fiber and Application, 2017, 42 (4): 27- 31.
GENG Z Z , LI H , YANG M , et al. Preparation and properties of polyimide modified C/C composites[J]. Acta Materiae Compositae Sinica, 2019, 36 (1): 186- 191.
YU M M , XUE K , LIU X Q , et al. High temperature and tribological properties of a carbon fiber reinforced binary matrix composite[J]. Polymer Materials Science & Engineering, 2021, 37 (8): 93- 101.
10
陈烈民, 杨宝宁. 复合材料的力学分析[M]. 北京: 中国科学技术出版社, 2006.
10
CHEN L M , YANG B N . Mechanical analysis of composites[M]. Beijing: China Science and Technology Press, 2006.
QIN L , LUO R Y . Effect of pyrolytic carbon on properties of precursor impregnated pyrolysis 3D-Cf/SiC composites[J]. China Ceramic Industry, 2018, 25 (1): 1- 6.
12
王兴业. 复合材料力学分析与设计[M]. 长沙: 国防科技大学出版社, 1999.
12
WANG X Y . Mechanical analysis and design of composites[M]. Changsha: National University of Defense Science and Technology Press, 1999.
ZHANG D S , LI X T , XIA H H , et al. Nanoindentation behavior of three different carbon fibers[J]. Acta Materiae Compositae Sinica, 2017, 34 (6): 1340- 1346.
PENG X F , DAI Z M , JIANG J J , et al. Study on nano indentation behavior of C/C composites with different carbon substrates[J]. Equipment Environmental Engineering, 2019, 16 (10): 64- 70.
WANG C , SHU Z , SHAN H , et al. Study on the effect of temperature treatment on the properties of polyimide films[J]. Mechanical & Electrical Engineering Technology, 2018, 47 (11): 26- 28.
2023, Vol. 51 
), 姚彧敏, 杨敏, 陶银萍, 任慕苏, 孙晋良
