In order to study possibilities of application of rapid solidification ribbons to an insert metal for solid phase diffusion welding of Ni-base supearlloy, welding was carried out by changing the welding pressure, time, and temperature using Ni-base superalloy ribbons (IN738LC, TMP-3, René 80, and Ni-Al-X three compositional alloys) produced by twin-roll rapid solidification process. The ribbon has almost similar composition to the base metal (René 80) and superplastic potential, then it needs relatively small flow stress on deformation. In this report, the influence of ribbon usage as an insert metal and carbon content in the ribbon on the joint strength were studied. The results are as follows,
(1) The joint strength increases by using the ribbon for an insert metal compared to that without ribbons.
(2) Carbide and oxide are formed on the welded interface during welding, resulting in decrease in welding strength.
(3) The joint strength is increased and fractured position changes from the welded interface to the base metal, as the carbon content in the ribbon is decreased.
