Continuous C fibre composites with a porous ZrB2 Matrix

Highlights: • Carbon fibre–ZrB₂ matrix composites were fabricated via infiltration and hot pressing. • Addition of sintering aids is adopted to build up the CMC matrix. • The weak matrix–fibre interface enables damage tolerant behaviour. - Abstract: ZrB₂–continuous C fibre composites were prepared by vacuum-bag infiltration and hot pressing, using 1D fabric carbon preforms from different commercial products. Sintering behaviour and microstructural features such as secondary phases and matrix/fibre interface were analysed. The infiltration process allowed the overall fibre content to be increased up to 70 vol.%, whilst the matrix densification was enabled by sintering aids. Due to presence of residual porosity, the degree of chemical interaction at the fibre/matrix interface was limited and this resulted in an easier pull out in the fractured surfaces, even in absence of fibre protective coating. The composites exhibited a damage tolerant behaviour.