炭纤维及树脂对C/C-SiC摩擦材料性能的影响

【作者】 秦明升；

【导师】 肖鹏；

【作者基本信息】 中南大学 ， 材料学， 2009， 硕士

【摘要】 由于具有密度低、耐腐蚀、抗氧化性好、优异的摩擦磨损性能等优点,C/C-SiC复合材料作为最新一代的摩擦材料具有广阔的应用前景。本论文结合课题组前期已有的研究成果,采用周期短、成本低的温压-原位反应法制备C/C-SiC,研究了硅化及热处理对纤维结构及强度的影响,树脂的热分解过程和不同短纤维和树脂对C/C-SiC力学和摩擦磨损性能的影响。结果表明：(1)HTA炭纤维硅化处理后拉伸强度由处理前的3.15GPa下降到0.32GPa。320K预氧丝热处理后表面粗糙度降低较多,强度由处理前的0.26GPa提高到处理后的1.62GPa。(2)硼改性酚醛树脂850℃炭化后残碳率为64%,线收缩和体积收缩分别为14.6%和37.9%,该树脂在室温-200℃和500-700℃两阶段热失重速率较大。无机纳米改性酚醛树脂850℃炭化后残碳率为58%,线收缩和体积收缩分别为23.4%和48.4%,该树脂在350-700℃阶段热失重速率较大。(3)不同纤维增强的C/C-SiC试样中,T700增强的材料的力学性能较好,其抗压强度随纤维体积含量的增加先增后减,其垂直、平行抗压强度在含量为10%时有最大值75.44MPa.58.14MPa;冲击强度随着纤维含量的增加而增加,在23%时有最大值为1.74 KJ/m2。预氧丝增强的C/C-SiC试样的垂直抗压强度表现为先增后减,在10%时有最大值49.34MPa,而平行抗压强度逐渐降低,在8%有最大值49.34MPa；冲击强度表现先增后降,在15%有最大值1.50KJ/m2。(4)不同树脂做粘结剂制备的C/C-SiC试样中,树脂含量较低时,硼改性树脂做粘结剂制备的材料的抗压强度较高,冲击强度较低。硼改性树脂做粘结剂制备的材料的抗压强度随树脂含量的增加而减小,垂直、平行抗压强度在22.5%时有最大值86.18MPa.64.77MPa;冲击强度表现为先增后降,在37.5%有最大值1.80KJ/m2。无机纳米改性树脂做粘结剂制备的试样的抗压强度随着树脂含量的增加先增后减,其垂直、平行抗压强度在37.5%时有最大值84.07MPa,71.1MPa,冲击强度表现为逐渐下降,在22.5%有最大值1.95 KJ/m2。(5)不同纤维增强的C/C-SiC试样中,T700增强的试样的摩擦系数在0.50-0.73范围内,纤维含量为10%的试样的摩擦系数波动较大,23%含量的试样的摩擦系数的波动较小；纤维含量为10%的试样的磨损率在0.17～19.2×10-7·cm3·N-1·m-1内波动；纤维含量为23%的试样的磨损率在0.7～0.81×10-7·cn3·N-1·m-1内波动。预氧丝增强的试样的摩擦系数在0.54-0.72范围内,纤维含量为23%的试样的摩擦系数较小且波动较小；预氧丝含量为15%的试样的磨损率在0.46-1.09×10-7·cm3·N-1·m-1内变化,波动较小；而10%的试样的磨损率在0.66～16.67×10-7·cm3·N-1·m-1呈正弦波动,波动较大。整体来看,预氧丝增强的材料的摩擦系数和磨损率较大。(6)不同树脂做粘结剂制备的C/C-SiC试样中,硼改性树脂制备的试样的摩擦系数在0.50-0.72范围内,40%树脂含量的试样的摩擦系数波动较小；22.5%树脂含量的试样的磨损率在0.42-21.76×10-7·cm3·N-1·m-1范围变化,波动较大,30%树脂含量的试样的磨损率在0.7～0.8×10-7·cm3·N-1·m-1范围变化,波动较小。无机纳米改性的树脂制备的试样的摩擦系数在0.56-0.78范围内,30%树脂含量的试样的摩擦系数波动较小；40%树脂含量的试样的磨损率在0.38-1.18×10-7·cm3,N-1·m-1范围变化,波动较大,37.5%树脂含量的试样的磨损率在0.47-0.64×10-7·cm3·N-1·m-1范围变化,波动小。整体来说,无机纳米改性的树脂制备的材料的摩擦系数较大,磨损较小。更多还原

【Abstract】 C/C-SiC composites has broad application prospect as the newest generation friction materials because of its advantages of low density, excellent oxidation resistance and good friction properties. In this paper, the short periods and lower cost warm pressing and in-situ reaction process was used to manufacture C/C-SiC,The effects of siliconization and heat treatment on the structure and intension of carbon fibre,the heat decomposition of resin,the effects of different carbon fibres and resins on the performance of C/C-SiC were researched.The results show that:(1) The pull intensity of HTA after siliconization reduced to 0.32 GPa from 3.15 GPa, The surface roughness of preoxidized fibre after heat treatment decreased and intensity increased to 1.62GPa from 0.26 GPa.(2) The remnant carbon rate of boron-modified phenolic resin after carbonization at 850℃was 64%,the line shrink and bulk shrink rate were 14.6%and 37.9%, its weight loss velocity in the 25-200℃and 500-700℃phases was high. While The remnant carbon rate of Inorganic nano-modified phenolic resin after carbonization was 64%,the line shrink and bulk shrink rate were 23.4% and 48.4%,its weight loss velocity of nano-modified phenolic resin in the 350-700℃phase was high.(3) In the different fibres enhanced C/C-SiC samples, The mechanics performance of T700 enhanced C/C-SiC was better,with the fiber volume increasing,its compressive stress firstly increased then decreased and impact stress increased, composites have the best vertical compressive stress(75.44MPa),parallel compressive stress(58.14MPa) when fiber volume was 10%, composites have the best impact stress(1.74 KJ/m2) when fiber volume was 23%.With the fiber volume increasing, the vertical compressive stress and impact stress of preoxidized fibre enhanced C/C-SiC firstly increased then decreased, composites have the best vertical compressive stress(49.34 MPa)when fibre volume was 10% and have the best impact stress(1.5 KJ/m2) when fibre volume was 15%,while the parallel compressive stress of preoxidized fibre enhanced C/C-SiC decreased, the best parallel compressive stress was 49.34 MPa when fibre volume was 8%. (4) In the C/C-SiC samples made of different resins adhesive,when the resin volume was low, the compressive stress of C/C-SiC made of boron-modified resin was better,while its impact stress was worse. With the resin volume increasing, the compressive stress of C/C-SiC made of boron-modified resin decreased and impact stress firstly increased then decreased,composites have the best vertical compressive stress(86.18MPa) and parallel compressive stress (64.77MPa)when fibre volume was 22.5% and have the best impact stress(1.8 KJ/m2) when resin volume was 37.5%. The compressive stress of C/C-SiC made of Inorganic nano-modified resin firstly increased then decreased and the impact stress decreased, composites have the best vertical compressive stress(84.07MPa) and parallel compressive stress (71.10MPa)when fibre volume was 37.5% and have the best impact stress(1.95 KJ/m2) when resin volume was 22.5%.(5) In the different fibre enhanced C/C-SiC samples, The friction coefficient of T700 enhanced C/C-SiC fluctuated between 0.5 and 0.73,its friction coefficient and wear rate fluctuated greatly when fibre volume was 10% but fluctuated smallv when fiber volume was 23%. The friction coefficient of preoxidized fibre enhanced. C/C-SiC fluctuated between 0.54 and 0.72,its friction coefficient fluctuated smally when fibre volume was 23%, its wear rate fluctuated greatly when fibre volume was 10% and smally when fibre volume was 15%.Generally,the friction coefficient and wear rate of preoxidized fibre enhanced C/C-SiC were higher.(6) In C/C-SiC samples made of different resins, The friction coefficient of C/C-SiC made of boron-modified resin fluctuated between 0.5 and 0.72,its friction coefficient fluctuated smally when resin volume was 40%, its wear rate fluctuated smally when resin volume was 30% and fluctuated greatly when resin volume was 22.5%.The friction coefficient of C/C-SiC made of Inorganic nano-modified resin fluctuated between 0.56 and 0.78,its friction coefficient fluctuated smally when resin volume was 30%, its wear rate fluctuated greatly when resin volume was 40% and smally when resin volume was 37.5%. Generally,the friction coefficient of C/C-SiC made of Inorganic nano-modified resin was higher and its wear rate was lower.更多还原