Investigation of Constant Speed Tribological Behavior of Carbon- Carbon Composites

• Main Authors: Jin-Duo Chen, 陳金多
• Other Authors: Chien-Ping Ju，Jiin-Huey Chern lin
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/37580391586288373484

博士 === 國立成功大學 === 材料科學(工程)研究所 === 83 === This thesis compares the basic properties and the tribological behavior under different wear conditions of six different carbon-carbon composites, including one two-dimensional PAN/ CVI- (E), one two-dimensional pitch/ resin/CVI- (A), one three- dimensional PAN/pitch- (T3D) and three two-dimensional PAN/ pitch- (TH, TM and TL) based carbon-carbon composites. The corresponding tribology mechanism is also discussed. The results demonstrate that, after wear, three different types of debris morphologies on the worn surfaces are identified. The smooth type I and type III debris film is able to lubricate, but the powdery type II debris is not. Whenever a morphological transition (type I - to -type II) occurs, transition in friction and wear also occurs. For the sliding conditions of high sliding speed and load, and low humidity generally accelerate the occurrence of transitions. On the other hand, with increasing speed and load, and decreasing humidity, the worn surface condition become more severe. The minimum weight loss is measured in the specimen sliding at the same speed as that for breaking-in. During wear test, the debris layers are deformed and fractured, the damage increases with the sliding distance. The occurrence of transition can be attributed to the adsorption of condensable vapors (or gases). The transition takes place immediately when the amount of adsorption is below a critical value. The initial type I debris is formed and is able to lubricate according to the preferred orientation and vapors adsorption theories of the basal planes. The basal planes of type II debris are aligned in random order causing lack of lubrication. All of the collected debris from type II is particulate-type. During the wear process with mild wear condition, the particulate type II debris is flatten to become lubricative type III film, and the collected debris is lamina-type.