石墨烯增强铜基复合材料的制备和性能研究

发布时间：2019-06-11 22:43

【摘要】：石墨烯(Graphene)是一种由碳原子以sp~2杂化轨道按照蜂巢晶格排列,只有一个碳原子厚度的二维层状材料。具有杰出的机械、导热、导电性能。石墨烯被认为是一种理想的铜基复合材料增强体,提高基体强度的同时保证具有良好的导热性能。球磨是最广泛分散石墨烯粉体的方法,然而球磨时间和石墨烯含量对铜基复合材料性能的影响有待进一步研究。本文首先采用Hummers制备氧化石墨烯(graphene oxide,GO),然后使用高能球磨的方法使得氧化石墨烯均匀的分散在铜基体中。最后采用热压烧结的方法制备了石墨烯增强铜基复合材料。利用金相显微镜、X射线衍射和扫描电镜等方法研究了石墨烯在复合材料中的分散情况和不同球磨时间与石墨烯含量对复合材料的组织,结构,性能的影响。通过对X射线衍射、扫描电镜、原子力和FT-IR光谱的分析表明:Hummers法对原始石墨进行了有效的剥离,制得的氧化石墨烯层数较少。并且氧化石墨烯上存在大量的含氧基团,使得氧化石墨烯具有很强的界面结合能力。对复合粉体进行5h的球磨后实现了石墨烯的均匀分散,并且石墨烯的结构相对完整。对不同石墨烯含量复合材料的组织和性能的研究发现,当石墨烯的含量为0.5 wt.%时复合材料的性能到达最佳,相比于纯铜其抗拉强度提高了28%,导热系数提高了33.8%,并且其延伸率没有明显下降。复合材料的断口形貌主要表现出脆性断裂和韧性断裂相结合的特征,石墨烯主要分布在复合材料的边界处,呈现出明显的拔出和断裂状态。
[Abstract]:Graphene (Graphene) is a two-dimensional layered material with only one carbon atom thickness, which is arranged according to the honeycomb lattice by carbon atoms in sp~2 hybrid orbit. With outstanding mechanical, thermal conductivity, electrical conductivity. Graphene is considered to be an ideal copper matrix composite reinforcer to improve the matrix strength and ensure good thermal conductivity. Ball milling is the most widely dispersed graphene powder. However, the effects of milling time and graphene content on the properties of copper matrix composites need to be further studied. In this paper, graphene oxide (graphene oxide,GO) was prepared by Hummers, and then graphene oxide was uniformly dispersed in copper matrix by high energy ball milling. Finally, graphene reinforced copper matrix composites were prepared by hot pressing sintering. The dispersion of graphene in composites and the effects of different milling time and graphene content on the microstructure, structure and properties of graphene composites were studied by means of metallographic microscope, X-ray diffraction and scanning electron microscope. The analysis of X-ray diffraction, scanning electron microscope, atomic force and FT-IR spectra showed that the original graphite was effectively peeled off by Hummers method, and the number of graphene oxide layers was small. There are a large number of oxygen-containing groups on graphene oxide, which makes graphene oxide have strong interfacial bonding ability. After 5 h ball milling of the composite powder, the uniform dispersion of graphene was realized, and the structure of graphene was relatively complete. The microstructure and properties of composites with different graphene content were studied. it was found that the properties of the composites reached the best when the graphene content was 0.5 wt.%. Compared with pure copper, the tensile strength and thermal conductivity of the composites were increased by 28%, the thermal conductivity was increased by 33.8%, and the extensibility did not decrease obviously. The fracture morphology of the composites mainly shows the combination of brittle fracture and ductile fracture. Graphene is mainly distributed at the boundary of the composite, showing obvious pullout and fracture state.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB333

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