Fibre re-arrangement and matrix softening phenomena in matrix-coated fibre (MCF) composites during vacuum hot pressing consolidation

Experiments were carried out under constant load with increasing temperature during uniaxial constrained compression (vacuum hot pressing) to investigate the consolidation behaviour of matrix-coated fibres (MCFs). Regular fibre arrays were achieved in the consolidated specimen by a fine control of the die assembly from which the matrix deformation behaviour was extracted. The results indicate that there exists a softening temperature at which the MCFs start to deform rapidly, which leads to a high densification rate. The mechanisms involved are discussed. This observation is of significant consequence to the design of the composite fabrication process.