Preparation And Study On Advanced Cu-based Self-lubricating Friction Materials

With the purpose of the sliding mechanical frictional components’regular application in little lubricating oil or a little lubricating oil conditions, the study of high-performance advanced self-lubricating materials not only has important scientific research significance, but also has important application prospect. Graphite is one of the most popular lubricants, however the wettability is unsatisfactory. With the graphite increasing in copper matrix, though the self-lubricating is improved, the strength will decline, which is a bottleneck problem in developing high-performance advanced self-lubricating materials To solve this problem, in this paper, I use the Ni-coated graphite instead of the ordinary graphite to prepare copper-graphite self-lubricating materials, it will provide theoretical basis and support technique for high-performance advanced self-lubricating materials. Then, I study the properties of the carbon fibre reinforced copper-graphite self-lubricating materials.The microstructures, fracture morphologies, worn surfaces and phases were analyzed by OM(optical microscope), SEM(scanning electron microscope), XRD(X-ray diffraction), EDS(energy dispersion spectrometer), respectively. Also, the hardness and the crushing strength were tested by macro Vicker hardness tester and tensile testing machine, respectively. Last, the wear and friction properties were tested by wear testing machine.The analysis results show that with chemical plating technology, in the condition of alkalinity liquid and low temperature, we can plate a uniform and continuous Ni-P layer. And that under the sintering temperature940℃, the layer won’t fall off.The graphite particles which are plated with a layer of Ni-P improved the wettability, the sample’s mechanical properties prepared with the coated graphite are higher than those of the original graphite. When the content of graphite is3%, the sample’s crushing strength is116MPa and the hardness is33.6HV, which are prepared by the original graphite while those are151MPa and37.6HV prepared by the coated graphite. The friction coefficient is0.28and the wear losses is20mg which prepared by the original graphite while those are0.21and12mg.The carbon fibre’s addition improved samples’ mechanical properties. The mechanical properties increase first and decline second with the content of carbon fibre more. When the volume fraction reached11%, the mechanical properties reached maximum, the sample’s crushing strength achieved up to222MPa and the hardness achieved up to57.8HV. The carbon fibre obviously improved the friction wear performance, the degree of wear were relieved. When the volume fraction reached11%, it’s friction coefficient is0.09, the prepared sample has good self-lubricating properties, and the wear losses is4mg.