Dynamic interaction between the dislocations and cavities in tungsten during tensile test

Abstract

The irradiation hardening factor of the cavities (helium bubbles) in tungsten, as the divertor candidate material, in nuclear fusion reactor, has been investigated through an in-situ TEM observation during tensile test. The obstacle barrier strength α has been calculated by the bow-out behavior of a dislocation based on the line tension model. The obstacle barrier strength α of the cavity with a diameter of 2 nm in W has been measured to be 0.53 ± 0.02. The fraction of cross-slip behavior except the obstacle-cutting mechanism owing to the dynamic interaction between a dislocation of screw type and a cavity has been about 11 %. The fraction of cross-slip behavior of the screw dislocation in W has been smaller than those of other BCC structure materials.

Keywords

• Tungsten
• In-situ TEM observation
• Obstacle barrier strength
• Dislocation
• Tensile test
• Slip plane