The Structure of Nb Obtained by Severe Plastic Deformation and its Thermal Stability
Evolution of structure of Nb subjected to high-pressure torsion (HPT) with various strain at cryogenic and room temperatures and further annealing in the temperature range of 100-7000C has been studied by transmission electron microscopy (TEM) and microhardness measurements. HPT in liquid nitrogen enables to obtain true nanocrystalline structure with crystallite sizes of about 75 nm and the record-breaking microhardness of 4800 MPa. The thermal stability of the structure obtained is analysed.
Jing Tao Wang, Roberto B. Figueiredo and Terence G. Langdon
V. V. Popov et al., "The Structure of Nb Obtained by Severe Plastic Deformation and its Thermal Stability", Materials Science Forum, Vols. 667-669, pp. 409-414, 2011