Joining of fibre reinforced metal matrix composite materials

The joining processes of metal matrix composite materials (MMC), especially those reinforced with fibres and the problems involved in each process are briefly reviewed in this literature survey. The report focuses on the fibre reinforced aluminum matrix composites. The joining processes described include diffusion bonding, resistance welding, brazing, soldering and fusion welding. These joining processes require heating and/or pressure which tend to cause the degradation of MMC joint properties. The strength of the joint produced by any of these processes therefore remains markedly inferior to the base materials. The poor joint strength can be attributed to the destruction or the change in configuration of the fibre and to the formation of brittle phases at the fibre/matrix interface. Although various efforts have been taken to improve the MMC joint strength, the joint efficiencies reported are still at an unsatisfactory level to utilize the full potential of MMC. Further investigations and development work are urgently needed to establish reliable joining methods and procedures for MMC in order to use these materials in wider and more demanding applications. Thermal joining processes can in general be expected to yield better results by shortening the thermal cycle and, hence, the time for reactions responsible for degradation of the joint strength.