Effect of microstructural anisotropy on the mechanical properties of K-doped tungsten rods for plasma facing components

Abstract

The effect of microstructural anisotropy in pure tungsten (W) and potassium (K) doped W rods (20mm in diameter) on their mechanical properties was investigated by tensile tests along the axial and radial directions at temperatures from 473K to 1573K and fracture analysis. K-doping led to improved tensile strength regardless of the test direction and temperature. K-doping did not alter the elongation regardless of the test direction in the temperature range showing ductile fracture. The ductility at lower temperature range was improved by the K-doping, especially in tensile tests along the radial direction. The lowest temperature of ductile fracture along both axial and radial directions decreased from 1373K to 973K because of K-doping. Thus, K-doping could suppress the influence of microstructural anisotropy on tensile properties, especially ductility, in large diameter W rods.