High-temperature tensile ductility in WC-Co cemented carbides

High-temperature tensile deformation in WC-Co was investigated at temperatures between 1150 °C and 1250 °C. The flow stress is sensitive to temperature, strain rate, volume fraction of binder, and the addition of other carbides. The stress-strain rate relationship is divided into three regions at each temperature as in superplastic metals. A large tensile elongation over 100 pct was first obtained in WC-6Co and WC-13Co (wt pct) at temperatures of 1200 °C. Contrary to superplastic metals, the largest tensile elongation is not obtained in region II but on the border of regions I and II. The failure mode changes from necking in region I to sharp cracking in region II.