THEORETICAL-MODEL FOR SOLID-STATE CONSOLIDATION OF LONG-FIBER REINFORCED METAL-MATRIX COMPOSITES

A quantitative theoretical model has been established for the solid-st ate consolidation process of long-fibre reinforced metal-matrix compos ites, involving the bonding of aligned fibre mats and matrix foils. Th e analysis is based on a rectangular fibre array and takes into accoun t the plastic flow and power-law creep of the matrix, which are taken as the dominant mechanisms of consolidation. Theoretical predictions a re examined and compared with experiments on the consolidation of mono filament SiC fibres and a Ti-6Al-4V matrix. These generally show a goo d agreement, particularly for the samples with relatively closely spac ed fibres processed using comparatively high presures. The model overe stimates the bonding time to some extent when wide fibre spacing and l ow pressures are involved, due to nonrectangular fibre arrangements en countered in the present experiments and the possible effect of diffus ion that is not considered in the creep-based analysis. Contact pressu res at fibre/matrix interfaces at the initial stages of consolidation are also quantitatively determined and can be used to tailor the proce ss for minimum fibre damage.