炭/炭复合材料摩擦性能与摩擦表面状态的关系

Relationship between Friction Properties and Friction Surface Status of C/C Composites

金相显微分析炭/炭复合材料试样的热解炭结构,测试不同试样的硬度和石墨化度值,在国产MM-1000型摩擦试验机上,进行模拟飞机正常刹车试验,通过扫描电镜(SEM)对摩擦后的表面及磨屑进行形貌观察,傅立叶变换红外光谱仪(FTIR)定性地分析表面的摩擦膜,研究摩擦性能与摩擦表面状态的联系。结果表明:经过1600℃热处理后,炭/炭复合材料无法获得良好的摩擦磨损性能,碳微晶结构的缺陷和表面膜的不完整性,导致了明显的氧化及吸附的产生。2650℃热处理后,粗糙层(RL)结构热解炭具有更好的延展性,易于形成连续致密的具有自润滑效应的摩擦膜,但是更大程度上,增大了摩擦过程中的有效接触面积,碳结构的完整性及表面膜的实体完整性提高,与A试环相比具有较好的摩擦磨损性能;采用树脂炭补增密技术的双元炭基体试环,摩擦膜实体完整连续性得到进一步提高,对应了更少的氧化及吸附,表现出最佳的摩擦磨损性能。

The pyrocarbon structures of C/C composites were analysed on PLM. The hardness and graphitization degree of serious samples were tested, and the tribological behavior by simulating airplane normal landing condition on a MM- 1000 brake dynamometer was also investigated. The worn surfaces were observed with a scanning electron microscope （SEM）, also the films were analysed by FTIR in order to kriow the relation between friction properties and friction surface status. The results indicate： specimens heat-treated at 1600℃ can not reach the best friction and wear properties for defect of carbon micro-crystallite and uncompleted film layer, which lead generation of apparent oxidation and adsorption. After heattreated at 2650℃, continuous and dense friction layer with self-lubrication easily forms for ductility of the rough laminar （RL） pyrocarbon, but increases the effective contacting area at an extent, which increases the integrity of carbon and entire integrity of surface film layer. The specimen represents better friction and wear properties comparing with specimens A. The entire integrity of friction film further increases for specimen with resin densification, which reduces the oxidation and adsorption, and the specimen exists the best friction and wear properties.