Effect Of Infiltration Metal On Structure And Properties Of C/C Composite Materials

At present, with the speed-upping trend of electrical locomotive, the powdermetallurgical pantograph sliding plate that is the major of pantograph sliders in our country isnot suit for the faster railway. It's known that carbon's good lubricant performance andcarbon fiber's perfect strength and module performance is widely used in fiber reinforcedmaterials. At the same time, copper and aluminium have good conductivity and high strength.In this paper, we have prepared three composite materials of C/C, C/C+Cu, C/C+Al whichhave perfect integrate capability to be used as pantograph sliders.The research of this paper is that the evaluation of the materials performances such asdensity, electrical conductivity, flexural strength and surface hardness of C/C composite,C/C+Cu, C/C+Al. Sampling that are carried out wear experiment has studied the relations aswell as wear loss, load and friction coefficient, wear distance.Based on the researches above, the conclusions of this paper are as follows:1 The density of C/C+Cu and C/C+Al composites is 4.58g/cm~3,2.28 g/cm~3, respectively.These values are lower than many other pantograph sliders materials. It is propitious to thedevelopment of contract strips materials. The electric conductivity of composites is 0.24μΩm,0.184μΩm respectively, which is much lower than the C/C composite that is 3.66μΩm. Thisresult means that the C/C+Cu, C/C+Al composites achieve the requirement of pantographsliders.2 The flexural strength of C/C+Cu, C/C+Al composites is 88MPa, 196MPa. Thesenumbers mean that the composites have exceeded the standard in our country. In the processof three point bending experiment, the fibrous reinforcement plays an important role incomposites. Because the interface joined intensity of C/C+Al is better than C/C+Cu's, theflexural strength of C/C+Al is the best one in three composites.3 With infiltrating copper and aluminium, the friction coefficient and wearing capacityof C/C+Cu, C/C+Al are better than C/C composite. Further more, the wear property ofC/C+Al is ever the best.4 In the beginning of wear experiment, the major abrasion mechanism is grain abrasionand adhesive wear. After the appearance of lubricating layer, the abrasion mechanism ischanging to fatigue wear. The friction coefficient and wear loss are related to the lubricatinglayer. In the wear experiment, graphite content is benefit for improving the lubrication condition of wear surface. So when the lubricating layer appeared, the friction coefficient andwear loss are becoming lower and lower. When the wear layer flaking off, the sample startsthe grain abrasion and adhesive wear again, it aims to form the new layer. So the frictioncoefficient and wear loss are higher at the same time.