Extrinsic and intrinsic fracture behavior of high pressure torsion deformed nickel

Nickel discs (>99.5 wt.%) were deformed by high pressure torsion (HPT) at different temperatures (−196 °C, 25 °C, 200 °C, and 400 °C) until saturation was reached. The strength and fracture behavior of microdefect-free samples and samples with inclusions were investigated using micro and macro tensile tests, respectively. The fracture behavior is not sensitive to the HPT deformation temperature but differs significantly in the two types of sample. The ultimate tensile strength is not affected by inclusions or grain texture.