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

Abstract: This work investigated high-temperature four-point bending deformation of hot-pressed ZrB2 ceramics with WC additive at 1900°C for 0–60min in argon atmosphere under a static load of 25MPa. After 60min bending deformation, about 8% strain was achieved without apparent macroscopic cracks, suggestive of superplastic behavior at 1900°C. The tensile side and the compressive side of the deformed samples exhibited different microstructural characteristics. On the tensile side, many cavities were observed at the multigrain junctions and the fracture surface was relatively flat. On the compressive side very few cavities occurred and some large cracks were present on 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. [Copyright &y& Elsevier]