纳米炭纤维改性对C/C复合材料摩擦磨损的影响

Effect of carbon nanofiber modification on the tribological properties of C/C composites

采用催化化学气相法在炭纤维表面原位生长纳米炭纤维后,再通过化学气相渗透法制备出纳米炭纤维改性C/C复合材料。采用微动摩擦磨损试验考察纳米炭纤维改性C/C复合材料的摩擦磨损性能,探讨原位生长纳米炭纤维对C/C复合材料摩擦磨损机理。结果表明,采用纳米炭纤维改性后C/C复合材料的摩擦过程更平稳,磨损量减小。纳米炭纤维与热解炭形成复合基体,这种复合基体在摩擦过程中形成高强度高模量的摩擦膜,从而影响复合材料的摩擦性能。

Carbon nanofibers （CNFs） were grown on a carbon fiber preform that was then densified by chemical vapor infiltration to prepare CNF-modified C/C composites. Micro-friction tests were used to investigate the effect of the CNF modification on the tri- bological properties of the composites at reciprocating abrasion rates from 600 to 1 400 cycles/min over a distance of 15 mm and un- der a load of 60 N. Results show that the friction coefficient and the depth of the surface disturbed by the friction on the modified composites are not as sensitive to the rate as are the un-modified ones. When the rate is less than 1 000 times/rain, the modified composites have lower friction coefficients than the un-modified ones. The modified composites show steadier braking and their wear rates are much lower than the un-modified ones under the same rate. The wear debris formed from the matrix composed of CNFs and high-textured pyrocarbon helps maintain a high coefficient of friction and stable braking by forming a uniform film at the friction sur- face, resulting in the improved tribological properties.