Microstructural study of vapour grown carbon nanofibre/copper composites

Vapour grown carbon nanofibres from different manufacturers have been incorporated into copper in order to obtain metal-matrix composites with high volume fraction of reinforcement. The manufacturing route involved copper deposition by the electroless plating technique and further hot-pressing of the composite powders. A material with porosity less than 1% was obtained. The microstructure was investigated by scanning electron microscopy and transmission electron microscopy. After hot-pressing the carbon nanofibres were seen to be homogeneously dispersed in the matrix and showed a random planar distribution. Despite the poor wetting between copper and carbon, the Cu/C interface formed was continuous. The matrix was composed of grains in the nanometric range, suggesting that the nanofibres act as grain growth inhibitors.