Mechanical behaviour of mullite composites reinforced with mullite fibres

摘要: Abstract Mullite matrix composites uniaxially reinforced with uncoated and BN (0.3 or 1 μm thick) coated mullite fibres were consolidated to 82 98% of TD (theoretical density) at 1300 °C by using a colloidal processing route make matrix. The mechanical properties characterized flexural testing chevron-notch tests for fracture toughness measurement. samples 0.3 BN-coated failed in brittle manner without any toughening effect the fibres. In contrast, sample showed toughened composite behaviour (i.e. load-carrying capacity following maximum load) significant enhancement (e.g. about 12 MPa m 2 as-fabricated state), despite relatively low density 90% TD. room temperature ultimate strength (320 MPa) this decreased little heat treatment 1320 inducing complete transformation matrix, probably due degradation fibre strength.