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.