Beneficial effect of low BN additive on densification and mechanical properties of hot-pressed ZrB2–SiC composites

The incorporation of 1 wt% hexagonal BN (hBN) into ZrB2–30 vol% SiC could noticeably better the fracture toughness, hardness, and consolidation behavior this composite. This research intended to scrutinize effects various amounts hBN (0–5 wt%) on different characteristics ZrB2–SiC materials. hot-pressing method under 10 MPa at 1900 °C for 120 min was employed sinter all designed specimens. Afterward, as-sintered samples were characterized using X-ray diffractometry (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS), Vickers technique. addition up improved relative density, leading a near fully dense sample; however, 5 such an additive led composite containing more than 5% remaining porosity. highest hardness 23.8 GPa toughness 5.7 MPa.m1/2 secured sample introduced by only hBN. Ultimately, breaking large grains, crack bridging, deflection, branching, arresting as chief toughening mechanisms in ZrB2–SiC–hBN system.