Co-enhancement of oxidation resistance and mechanical properties of Cf/LAS composites: the effects of h-BN addition

Abstract Carbon fiber reinforced lithium aluminosilicate glass-ceramic composites have been extensively studied and widely used in industry applications, because of its good mechanical properties and low thermal expansion coefficient. However, further investigation is also need to improve its oxidation resistance and mechanical performance to meet higher requirements. In this work, Cf/LAS glass-ceramic composites were fabricated by a slurry impregnation and hot-pressing method with different amounts of h-BN. Results indicate that composites with 2 wt.% h-BN addition exhibit excellent flexural strength and fracture toughness, reaching 910 ± 22 MPa and 21 ± 1 MPa·m1/2, respectively, and that after oxidation at 600, 800 and 1000 °C for 1 h, their strength residual ratio can reach 47%, 35% and 32%, respectively. TEM analyses suggest the improvement of oxidation resistance and mechanical properties should be attributed to the unique interface of composites caused by h-BN addition.