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 (Cf). 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%).