【作者】 刘双进；

【导师】 崔春翔；

【作者基本信息】 河北工业大学 ， 材料学， 2003， 硕士

【摘要】 非连续C_f/Cu复合材料的电导热导率高，具有自润滑和抗电弧侵蚀等特殊性能，是一类具有广阔应用前景的功能复合材料。碳纤维在基体中的润湿性问题和均匀分布问题是该类复合材料制备中需要解决的关键技术问题。本课题尝试采用粉末冶金方法制备非连续C_f/Cu复合材料，对碳纤维的表面处理、复合材料的制备工艺进行了重点研究，并对复合材料的组织及性能进行了较为系统的研究。 本研究尝试多种方法对碳纤维表面进行氧化处理以提高镀层与碳纤维之间的结合力。试验发现采用热空气和浓硝酸联合氧化的方法可使碳纤维获得适于镀铜的表面状态。为解决碳纤维与基体间的润湿性问题，本研究采用多种镀液对碳纤维进行表面镀铜处理。试验表明采用柠檬酸盐镀液，可在碳纤维表面获得优质镀铜层，合理控制各种电镀工艺参数对镀铜效果有十分重要的影响。 尝试使用多种湿混剂对碳纤维和铜粉进行湿混处理，对比结果表明，(甘油+酒精)是制备非连续C_f/Cu复合材料的最佳湿混剂，它可使碳纤维在基体中得到均匀的分散。通过对比不同压制压力和烧结温度下复合材料的显微组织形貌，确定初压烧结的最佳工艺参数为：350MPa压制+400℃×1h除气+800℃×40min烧结。初压后，碳纤维在基体中的分布产生了一定的取向性。 复压复烧处理后，铜基体与碳纤维之间结合状态良好，复合材料的致密度、电导率及机械性能均有显著提高。显微组织分析表明，复合材料中仍存在一定数量孔隙，故实测密度和电导率明显低于理论值，制备工艺有待进一步完善。试验测试了不同碳纤维含量复合材料的摩擦磨损性能，分析了复合材料的摩擦磨损机理，并探讨了碳纤维在复合材料磨擦磨损中的重要作用。更多还原

【Abstract】 Discontinuous Cf/Cu composite, with its peculiar properties of high electrical-conductivity, high thermal-conductivity, self-lubricating, resisting electric-arc erosion and so on, is a prospectively functional composite. In the process of fabricating the composite, there are two key technical questions , that is the wetting quality and even-distribution of carbon fibers in matrix. In the study, powder metallurgy was adopted to fabricate discontinuous Cf /Cu composite. The surface treatment of carbon fibers and fabricating technology of the composite were two keys of the study. And microstructure and properties of the material were also researched more systemically.In the study, several ways were adopted for surface oxidation treatment of carbon fibers to improve binding strength between copper coating and carbon fibers. Final results indicated that the way being fit for plating copper on the surface of carbon fibers was that carbon fibers were oxidized in hot air and boiled in nitric acid at high temperature. To settle the wetting quality between carbon fibers and copper matrix, several solutions were used to treat with the surface of carbon fibers. A lot of experiments showed that the surface of carbon fibers might gain high quality plating copper coating in citrate solution and craft parameters of plating had great influence on plating copper.Several dispersants were used for mixing with carbon fibers and copper powders. The experiment showed that (glycerin + alcohol) was an optimal dispersant used for fabrication of discontinuous Cf /Cu composite, because it could redound to well-distributing of carbon fibers in the matrix. By analyzing microstructure and morphology of the composites at the different pressure and different sintering temperature, optimal craft parameters of primary pressing-sintering were ascertained: 350MPa (pressing) + 400 C + lh (clearing gas) + 800 C + 40min (sintering).After primary press, the carbon fibers showed some directional distribution.The composite was pressed and sintered again to further enhance its synthetical properties. Through this treatment, interface binding strength, compactness, conductivity and mechanical properties of the composite were prominently increased. The analysis of microstructureindicated that there were still certain amount of holes, so its density and conductivity were evidently under theoretic value. Based on the reason, the fabricating technology of the composite needed further perfecting. Through testing the wear and tear properties, analyzing the mechanism of wear, results showed that carbon fibers were in favor of enhancing antifriction and wear-resist properties of the discontinuous Cf /Cu composite.更多还原