Fabrication, microstructure and multi-scale mechanical properties of 2.5D oxide fiber reinforced oxide composites

Abstract

2.5D oxide/oxide composites have attracted substantial attention due to their good integrity. In this work, a simple process was used to manufacture the 2.5D aluminosilicate fiber reinforced alumina (2.5D-ASf/Al2O3) composites. The influence of 2.5D preform on the microstructure of the 2.5D-ASf/Al2O3 composite was studied in-depth mainly by X-ray computed tomography. Also, the change mechanism of the micro- and macro- mechanical properties of composites, especially the anisotropic mechanical properties were further analyzed. The results showed that the matrix modulus and fiber strength had great effects on the mechanical properties of the 2.5D-ASf/Al2O3 composites with different densification cycles. And the microstructure characteristics of the 2.5D-ASf/Al2O3 composites were consistent with those of the 2.5D preform, such as the warp direction cross-sections invariably had higher porosity of the pores>10 μm and larger pores than the weft direction cross-sections. This was also one of the key factors affecting the anisotropic mechanical behavior of the 2.5D-ASf/Al2O3 composites.