Synthesis and microstructure evolution of β-Sialon fibers/barium aluminosilicate (BAS) glass-ceramic matrix composite with enhanced mechanical properties

Dense Sialon fibers/barium aluminosilicate (BAS) matrix self-reinforced composite was synthesized by one-step method without applying pressure before or during sintering process. In this work, BAS matrix and internal Sialon fibers were synthesized successfully by directly sintering precursor powders at 1400°C for 4 h. The BAS is not only introduced as a structural matrix material, but also as an effective liquid phase sintering aid to attain full densification bulk sample. The results show that the diameter of fibers is about 100–200 nm, and the quantity of the fibers can be changed with different temperatures. The obtained Sialon fibers/BAS matrix composites exhibit better toughness due to fiber bridging, crack deflection, and pullout. The sample with 3.5 wt% carbon content has maximum value of flexural strength (74.5 ± 3.5 MPa) and fracture toughness (3.2 ± 0.20 MPa·m^1/2). The growth of the Sialon fibers follows a vapor-liquid-solid (V-L-S) mechanism. These findings featured with a green and simple preparation process provide a facile strategy to design and fabricate the bulk ceramic matrix composites in complex shapes and different sizes.