ISSN   1004-0595

CN  62-1224/O4

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添加相结构对Cu/PTFE复合材料力热学及摩擦磨损性能影响

Additive Phase Structure on the Mechanical-thermal and Tribology Properties of Cu/PTFE Composites

  • 摘要: 为了探究添加相结构对Cu/PTFE复合材料力热学及摩擦磨损性能的影响,本文中采用真空热压烧结法分别制备了PTFE、颗粒增强Cu/PTFE复合材料和三维骨架增强Cu/PTFE复合材料,并使用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、DR-Ⅲ导热系数测试仪和UMT摩擦磨损试验机等对上述3种材料的微观组织、力学性能、导热性能和摩擦磨损性能进行了分析. 结果表明:颗粒增强Cu/PTFE复合材料中铜颗粒弥散分布于PTFE基体中,三维骨架增强Cu/PTFE复合材料中的骨架铜与PTFE基体通过互锁方式紧密结合在一起,且三维骨架增强Cu/PTFE复合材料由于骨架铜的均匀导热使复合材料制备过程中PTFE的晶化程度更好,其基体硬度略有提升;铜金属相的添加有效提高了PTFE基复合材料的承载和导热能力,其中三维骨架增强Cu/PTFE复合材料由于泡沫铜在三维空间形成连续导热通道和对载荷的有效分散,使其导热能力和承载能力明显优于颗粒增强Cu/PTFE复合材料;在摩擦磨损性能方面,铜金属相的添加明显改善了PTFE基复合材料的耐磨性,颗粒增强Cu/PTFE复合材料和三维骨架增强Cu/PTFE复合材料相对于PTFE材料,其耐磨性分别提升了32.9%和75.7%.

     

    Abstract: In order to investigate the effect of additive phase structure on the mechanical-thermal and tribology properties of Cu/PTFE composites. In this paper, the PTFE, particle-reinforced Cu/PTFE composites and three-dimensional skeleton-reinforced Cu/PTFE composites were respectively prepared by the vacuum hot-pressing and sintering method. And, the microstructure, mechanical properties, thermal conductivity and tribology properties of these three materials were investigated by using the Scanning electron microscope (SEM), X-ray diffraction (XRD), DR-III thermal conductivity tester, and UMT friction wear tester. The results showed that the copper particles in the particle reinforced Cu/PTFE composites were uniformly distributed in the PTFE matrix, and the skeleton Cu in the three-dimensional skeleton reinforced Cu/PTFE composites was tightly bonded with the PTFE matrix through interlocking mode. The three-dimensional skeleton reinforced Cu/PTFE composites compared to particle-reinforced Cu/PTFE composites, the three-dimensional skeleton reinforced Cu/PTFE composites were better crystallized in the composites during composites preparation due to the homogeneous thermal conductivity of the skeleton Cu, then its matrix hardness was slightly improved. The load-bearing and thermal conductivity of PTFE matrix composites were effectively enhanced by the addition of copper metal phase. For particle reinforced Cu/PTFE composites, the copper particles dispersed in the PTFE matrix and formed a structural discontinuity, so it improved the thermal performance at certain limitations, But, the three-dimensional skeleton reinforced Cu/PTFE composites could form a continuous thermal conductivity channel and can effectively dispersing the load , resulting in the thermal conductivity and load-bearing capacity of three-dimensional skeleton reinforced Cu/PTFE composites is significantly good than that of the particle reinforced Cu/PTFE composites. Friction and wear results showed the friction coefficient of three-dimensional skeleton reinforced Cu/PTFE composites was slightly higher than that of PTFE and particle reinforced Cu/PTFE composites. And, the particle-reinforced Cu/PTFE composites showed a small upward trend of the friction coefficient, which may have been attributed to the hard copper particles in the composite was gradual exposure out and resulting in the fluctuations of the friction coefficient. By comparing with the PTFE materials, the addition of copper metal phase significantly improved the wear resistance of PTFE-based composites. The plastic deformation in the matrix of the particle-enhanced Cu/PTFE composites and the three-dimensional skeleton reinforced Cu/PTFE composites was gradually reduced. In addition, the void structure of the copper foam skeleton has the accumulation of wear debris which could promoted the formation of the transfer film. So, the wear resistance of particle-reinforced Cu/PTFE composites and three-dimensional skeleton-reinforced Cu/PTFE composites were improved by 32.9% and 75.7%, respectively.

     

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