Microstructure and helium irradiation performance of high purity tungsten processed by cold rolling

This work aims to investigate the effects of confined cold rolling on the evolution of microstructure, hardness, and helium irradiation performance of high purity tungsten (W). Using a final rolling temperature of 450 °C, W samples were severely deformed by confined cold rolling up to equivalent strains (ε_eq) of 1.6 and 3.3. Experimental results indicate that the average grain size of W specimens processed by confined cold rolling has been greatly reduced, and the rolled W samples with ε_eq ∼3.3 do not show an “ideal texture” of (001)[110] which is the expected texture of bcc metals processed by conventional cold rolling. The irradiation resistance against 60 keV He⁺ ions with up to a dose of 1.5 × 10²² ions·m⁻² of the rolled W is compared to that of the as-received W. Results show that, due to an improvement of the metal's ductility, blister bursting with a partially opened lid forms on the surface of the rolled W, whereas blister bursting with a fully opened lid forms on the surface of the as-received W.