Realization of ODS-Cu/T91 Tube-to-tube Joining with Rotary Friction Welding

摘要

Non-melting tube-to-tube joining techniques between copper and steel are of significance for the development of monoblock type divertor components for future DEMO. In this study, tube-to-tube joining between T91 and ODS-Cu (reference materials), which is difficult to accomplish by traditional fusion welding, has been successfully realized with a rotary friction welding manner. The junctions are free of defects such as microcracks. Asymmetric diffusion of elements has been observed. Very narrow soft regions were found in ODS-Cu at the vicinity of the interfaces in all specimens. All the specimens have appreciable tensile strengths (290 to 330 MPa) but exhibit brittle characteristics. Both two as-received specimens were not broken after the scheduled rotary bending fatigue testing. Relationships among tensile properties (brittleness), microhardness (narrow soft region) and microstructures (asymmetric diffusion) have been tried to establish.