Friction welding of niobium and tungsten pseudoalloy joints

The friction welding of niobium and tungsten pseudoalloy D18 was investigated. The friction welding process was found to proceed differently than in the case of niobium–tungsten joints. Stable Nb–Fe–Ni–W intermetallic forms would occur in the joint zone. The use of copper as the intermediate layer prevented the intermetallic phases from forming and joints with a strength of 317 MPa were produced.

Research highlights
► Nb, D18 and W friction welding.
► Hard and brittle structures with microcracs.
► Cooper interlayer gives joint without hard microstructures.
► Stable Nb-Fe-Ni-W intermertallic forms occure in the joint zone.