Deformation and fracture behaviour, and thermal stability of ODS-Cu/ODS-Cu and SUS/ODS-Cu joints fabricated by advanced brazing technique

•To understand the excellent joint mechanism of the GlidCop®/GlidCop® and SUS/GlidCop® joints through the AMSB fabrication technique, deformation and fracture behaviour of the GlidCop®/GlidCop® and SUS/GlidCop® joints were investigated.•In the case of the GlidCop®/GlidCop®, deformation occurred predominantly in the diffusion layer with lower hardness, and the fracture proceeded almost at the center of the layer.•In the case of the SUS/GlidCop®, deformation occurred widely in both bulks near the bonding layer. The fracture proceeded mainly along the interface between the GlidCop® bulk and the bonding layer.•The diffusion layer and bonding layer showed an excellent thermal stability against a repetitive heat treatment. A joint of oxide dispersion strengthened copper alloy (ODS-Cu; GlidCop®), i.e., GlidCop®/GlidCop® joint and a joint of stainless steel (SUS) and GlidCop®, i.e., SUS/GlidCop® joint were prepared by using the advanced brazing technique (ABT). Deformation and fracture behavior, and thermal stability of these joints were investigated by means of three-point bending test, scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS). Firstly, in the case of the GlidCop®/GlidCop® joint, plastic deformation occurred predominantly in the diffusion layer with lower hardness. The fracture proceeded approximately at the center of the diffusion layer. In the case of the SUS/GlidCop® joint, on the other hand, plastic deformation occurred widely in the bulks, GlidCop® and SUS near the interfaces between the bulk and the bonding layer. The fracture proceeded mainly along the interface between the bonding layer and the bulk GlidCop®, and substantially along the interface between the bonding layer and the bulk SUS. Secondly, influences of 2nd-step heat on the GlidCop®/GlidCop® and SUS/GlidCop® joints were examined from viewpoints of microstructure and mechanical strength. Almost no obvious changes in the width of the diffusion layer (GlidCop®/GlidCop® joint) or the bonding layer (SUS/GlidCop® joint), and in the element distribution in these layers after the 2nd-step heat were recognized. In addition, any obvious changes in the shape of stress-strain curve and yield strength were not recognized for both joints.