A novel approach for manufacturing of layered, ultra-refractory composites using pliable, short fibre-reinforced ceramic sheets

A new additive technique for manufacturing of short fibre-reinforced ultra-refractory ceramics is presented. This technique allows the fabrication of solvent-free, thin (~100 µm), flexible, and easy-to-handle sheets suitable for fabricating homogeneous or layered structures. A large range of compositions, in terms of matrix and fibre volumetric contents, from 0% to 100% is possible. The amount of short carbon fibres incorporated in the sheets ranged from 20 to 50 vol%, whereas the fibre length ranged from 3 to 5 mm. The matrix composition investigated with this technique consisted of ZrB₂/SiC/Y₂O₃. By increasing the fibre amount from 35 to 50 vol%, an improvement of mechanical properties was observed. Four-point flexural strength (σ) ranged from 107 to 140 MPa, depending on the amount of carbon fibres (C_f). The same holds true for the work of fracture, ranging from 108 to 253 J/m². Functionally graded composites were fabricated by overlapping sheets with a fibre gradient (0%–50%).