High-temperature deformation of ZrB2 ceramics with WC additive in four-point bending

► The hot-pressed ZrB2 ceramics with WC additive exhibited the superplastic behavior at 1900 °C. ► On the tensile side of deformed sample, many cavitations were observed at the multigrain junctions and the fracture surface was relatively flat. ► On the compressive side, very little cavitations occurred and some large cracks existed in the fracture surface. ► The presence of a secondary W-containing phase formed by the addition of WC, prohibited the coalescence of cavities by its plastic deformation.