Volume 3, Issue 2 (February 2006)
The Effect of Joint Condition on Mechanical Properties of Irradiated Hot Isostatic Pressed Joints
For fabrication of the International Thermonuclear Experimental Reactor blanket, a study was made on the effect of surface roughness (Ry) at the joint boundary on tensite properties of copper alloy/stainless steel hot isostatic pressed (HIP) joints after neutron irradiation. Three different types of joints (type-A: Ry = 1 µm, type-B; Ry = 10 µm, and type-C: Ry = 30 µm) were prepared and irradiated up to 1.5 displacements per atom at 200–250°C. It was clarified that the tensile properties of unirradiated joints and tensile strength of irradiated joints were not changed by the surface roughness condition. However, total elongation of the high surface roughness (type-C) joints was smaller than that of the other joints after neutron irradiation, because diffusion of Cr and Fe into the copper alloy was not uniform compared with that of the other HIP joints. This study shows that a more uniform diffusion region is necessary for HIP joints to be used under neutron irradiation than for unirradiated Cu/stainless steel HIP joints.