Microstructure and mechanical properties of (ZrB2+ZrC)/Zr3[Al(Si)]4C6 composites prepared by in situ hot-pressing

Fully dense composites of Zr3[Al(Si)]4C6 were prepared by reactive hot-pressing. The composites were prepared from ZrH2, Al, Si, C and B4C and contained 10–30 vol% ZrB2+ZrC in a 2-to-1 M ratio. As reinforcing agents, ZrB2 and ZrC exhibited strengthening and toughening effects to the Zr3[Al(Si)]4C6 matrix. The bending strength was 625 MPa, the fracture toughness was 7.2 MPa m1/2, and the Vickers' hardness was 16.4 GPa.

► Novel Zr3[Al(Si)]4C6 matrix composites reinforced by different content of (ZrB2+ZrC) were prepared by in situ hot-pressing. ► In situ incorporated ZrB2 and ZrC show significant strengthening and toughening effect to the matrix. ► The composites show excellent mechanical properties (σc=625 MPa, KIC=7.2 MPa m1/2, HV=16.4 GPa).