Abstract
This paper investigates a new joining process for Ni based ODS alloy. This process is done without brazing and is designed to enhance the reliability of joints at high temperatures. The main feature of the process is the removal of surface oxide films by keeping ODS alloys at high temperature (1523 K) in vacuum (≈10−4 Pa) followed by successive solid state diffusion joining between the cleaned surfaces at 1473 K in the same vacuum chamber. Specimens joined by this new process exhibited both high tensile strength and high ductility comparable to the base metal. However, the ductility of the joints decreased slightly when heated at 1523 K for 2, 8, and 20 h in a vacuum, but this additional step substantially increased the tensile strength.
