【作者】 周涛；

【导师】 肖柱； 谭望；

【作者基本信息】 中南大学 ， 工程（专业学位）， 2022， 硕士

【摘要】 铜-碳复合材料是以铜为基体与碳材料复合而制得的铜基复合材料,广泛应用于电接触领域。然而,铜与碳之间的湿润性很差,两者的界面结合为机械结合,结合强度低。此外,在碳含量较高的材料中,碳在铜基体中的团聚现象也会对其综合性能产生不利影响。因此需要通过优化工艺控制碳材料在铜基体中的界面结合、结构、含量和空间分布特征等,充分结合铜和碳的优势,才能获得综合性能优良的铜-碳复合材料。本文利用氧化铜、氧化亚铜在高温下会与碳材料发生氧化还原反应的原理,以原位生成法制备了新型铜-石墨复合材料（Cu₂O-Gr）和铜-石墨烯复合材料（Cu-G-MO）,并对其组织和性能进行了分析研究。论文的主要结论如下:（1）与采用铜粉和石墨制备的Cu-Gr复合材料相比,Cu₂O-Gr复合材料表现出更高的力学性能和相近的导电率。Cu₂O-55Gr和Cu₂O-70Gr复合材料的抗压强度分别为141 MPa和67 MPa,分别比Cu-55Gr和Cu-70Gr复合材料高40%和25%左右。（2）Cu₂O-Gr复合材料中Cu/C界面的强度明显比Cu-Gr复合材料更高。原位反应使得基体中的部分石墨颗粒片层变薄,其尺寸更加细小,明显改善了石墨团聚的现象。（3）Cu₂O-Gr复合材料表现出比Cu-Gr复合材料更好的机械摩擦磨损性能。Cu-Gr复合材料的磨损机制主要表现为磨粒磨损和疲劳磨损,摩擦表面有明显的撕裂和破碎痕迹。Cu₂O-Gr复合材料的磨损机制表现为典型的磨粒磨损,摩擦表面呈犁沟状。Cu₂O-Gr复合材料的力学性能更好,其表面抵抗变形的能力更强,使其具有更好的耐磨损性能。细小且均匀分布的石墨颗粒有利于连续、完整润滑膜的形成,使其获得了更好的润滑效果。（4）在通电条件下,Cu₂O-55Gr复合材料表现出比Cu-55Gr复合材料更好的耐磨损性能,其磨损率比Cu-55Gr复合材料低25～50%。电流使得摩擦面局部温度升高,引起亚表层强度下降,加剧了粘附作用。同时,电流加快了石墨脱落速度从而促进了润滑作用,减少了磨粒磨损。材料的主要电磨损机制表现为粘着磨损和电弧烧蚀。（5）与采用常规热压法制备的铜-石墨烯复合材料（Cu-G）相比,采用微氧化铜粉与石墨烯原位制备的铜-石墨烯复合材料（Cu-G-MO）表现出更高的力学性能和导电率。在烧结过程中,微氧化铜粉能够与多层石墨烯发生原位反应,在生成Cu的同时,多层石墨烯得到了减薄,Cu/C界面的结合也得到了加强。图48幅,表17个,参考文献90篇更多还原

【Abstract】 Copper-carbon composites are copper matrix composites made of copper and carbon materials,which are widely used in the field of electrical contact.However,the wettability between copper and carbon is very poor.The interface between them is mechanical bonding and the bonding strength is low.In addition,in composites with high carbon content,the agglomeration of carbon in copper matrix will also have an adverse impact on its comprehensive properties.Therefore,it is necessary to optimize the process to control the interface bonding,structure,content and spatial distribution characteristics of carbon materials in copper matrix,and fully combine the advantages of copper and carbon in order to obtain copper-carbon composites with excellent comprehensive properties.Based on the principle that copper oxide and cuprous oxide will react with carbon materials at high temperature,new copper-graphite composites（Cu₂O-Gr）and copper-graphene composites（Cu-G-MO）were prepared by in-situ formation method,and their microstructure and properties were analyzed and studied.The main conclusions are as follows:（1）Compared with Cu-Gr composites prepared by copper powder and graphite,Cu₂O-Gr composites showed higher mechanical properties and similar conductivity.The compressive strength of Cu₂O-55Gr and Cu₂O-70Gr composites reached 141 MPa and 67 MPa respectively,about 40%and 25%higher than that of Cu-55Gr and Cu-70Gr composites.（2）The strength of Cu/C interface in Cu₂O-Gr Composites was significantly higher than that in Cu-Gr Composites.The in-situ reaction made some graphite particle lamellae in the matrix thinner and its size smaller,which significantly improved the phenomenon of graphite agglomeration.（3）Cu₂O-Gr composites showed better mechanical friction and wear properties than Cu-Gr composites.The wear mechanism of Cu-Gr composites was mainly abrasive wear and fatigue wear,and there were obvious signs of tear and breakage on the friction surface.The wear mechanism of Cu₂O-Gr composites was typical abrasive wear,and the friction surface was in the shape of furrow.Cu₂O-Gr composites had better mechanical properties and stronger surface deformation resistance,which made them have better wear resistance.Fine and evenly distributed graphite particles were conducive to the formation of continuous and complete lubrication film,so that they can obtain better lubrication effect.（4）Under the power-on condition,Cu₂O-55Gr composite showed better wear resistance than Cu-Gr composite,and its wear rate was 25～50%lower than Cu-55Gr composite.The current increased the local temperature of the friction surface,reduced the strength of the sub surface layer and intensified the adhesion.At the same time,the current accelerated the falling off speed of graphite,which promoted the lubrication and reduced the wear of abrasive particles.The main wear mechanisms of materials were adhesive wear and arc ablation.（5）Compared with copper-graphene composites（Cu-G-MO）prepared by copper powder and graphene,copper-graphene composites（Cu-G-MO）prepared by micro copper oxide powder and graphene in situ showed higher mechanical properties and conductivity.In the sintering process,micro copper oxide powder can react with multilayer graphene in situ.While Cu was formed in situ,the multilayer graphene was thinned and the bonding of Cu/C interface was strengthened.更多还原