Slurry infiltration and sintering cycle‐dependent mechanical properties of 3D oxide/oxide ceramic matrix composites

Abstract In this study, oxide/oxide ceramic matrix composites reinforced with three‐dimensional fiber preform were fabricated by a slurry infiltration and sintering (SIS) process. The influence of the SIS cycle on microstructures and mechanical properties of the 3D oxide/oxide composite was investigated. Results showed that the porous matrix was densified due to the SIS effect. The elastic modulus of the weak matrix and interfacial shear strength increased with the increasing SIS cycle. This led to an obvious improvement in flexural strength and interlaminar shear strength of the composite. The fracture toughness and work of fracture of the composite slightly decreased. A good balance between fracture strength and damage tolerance was achieved on the sixth SIS fabricated oxide/oxide composite, which had a high flexural strength of 295.1 ± 14.9 MPa, a high interlaminar shear strength of 18.2 ± .5 MPa, and a high fracture 11.5 ± .8 MPa m 1/2 . The SIS process is a promising way to fabricate the 3D oxide/oxide composite.