Zr元素对铜-石墨复合材料界面改性的影响

The Effect of Zirconium Content on the Interfacial Modification of Copper-graphite Composites

关键词:  铜-石墨复合材料  活性元素锆  微观组织  力学性能

Key words:  copper-graphite composites  Zr content  microstructure  mechanical properties

摘要:

[目的] 铜-石墨复合材料是一种重要的功能材料，界面问题是制约铜-石墨复合材料广泛应用的重要因素。因此，研究活性元素Zr对铜-石墨复合材料界面的影响机制具有重要意义。[方法] 采用真空热压烧结技术制备了4种Zr元素含量分别为0 vol.%，2 vol.%，5 vol.%和8 vol.%的铜-石墨复合材料。采用X射线衍射仪和配备能谱仪的场发射扫描电子显微镜对样品进行相组成分析和微观形貌观察，利用维式硬度计和静态液压万能试验机分别对样品进行硬度测试和压缩性能测试。[结果] 在900℃的真空环境下，活性元素Zr在铜基体与石墨的界面处与石墨反应生成了新相ZrC，新生成的ZrC在铜基体与石墨的接触界面形成一层均匀的过渡层。[结论] 力学性能测试发现硬质相ZrC的形成使铜-石墨复合材料的硬度和抗压强度显著增加。

Abstract:

[Objective] Copper-graphite composites are an important functional material, and the interface problem is an important factor that restricts the further extensive application of copper-graphite composites. Therefore, it is important to study the mechanism of the influence of active element Zr on the interface of copper-graphite composites.[Methods] Four kinds of copper-graphite composites with volume fractions of 0 vol.%, 2 vol.%, 5 vol.% and 8 vol.% Zr were prepared by using vacuum hot-press sintering. Phase composition and microstructure morphology of the samples were tested by XRD and SEM, respectively. The hardness and the compression of the samples were tested by the Vickers hardness tester and the static hydraulic universal testing machine, respectively.[Results] The results showed that in the vacuum environment of 900℃, the active element Zr reacted with graphite at the copper-graphite interface to form a new phase ZrC. The newly generated ZrC formed a uniform transition layer at the interface region.[Conclusion] It was found that the formation of the hard phase ZrC significantly increased the hardness and compressive strength of the copper-graphite composite by the mechanical property test.