Helium Induced Reduction of the Grain-Boundary Tensile Strength in Tungsten

Helium Induced Reduction of the Grain-Boundary Tensile Strength in Tungsten We perform an experimental investigation and computer modeling of the influence of the heliu m segregation on the inherent strength of high-angle grain boundaries in tungsten, which is a promising plasma-facing material in nuclear fusion devices. Tensile tests of tungsten bicrystals were conducted inside a field-ion microscope by means of high-field mechanical loading. It is shown that the intergranular helium adsorption induces reduction of the inherent grain-boundary tensile strength.