In situ synthesis, mechanical properties, and oxidation resistance of (SiC+ZrB₂)/Zr₃[Al(Si)]₄C₆ composites

In situ (SiC+ZrB₂)/Zr₃[Al(Si)]₄C₆ composites with 0-15 vol.% SiC and 15 vol.% ZrB₂ were prepared. As reinforcements, the incorporation of SiC and ZrB₂ shows significant strengthening and toughening effect by the synergistic action of mechanisms including particulate reinforcement, grain-refinement, and grain's pull-out, etc. The oxidation kinetics of the composites at 1000-1300 °C in air follows a parabolic law. With the incorporation and increase of SiC, the oxidation resistance of the composites is improved remarkably. It is attributed to the formation of a protective oxide scale containing borosilicate glass and more mullite, which effectively prevents the inward diffusion of oxygen.