Direct laser deposition of Cu-Mo functionally graded layers for dissimilar joining titanium alloys and steels

The dissimilar joining of titanium alloys and steel is more challenging due to the formation of brittle Ti-Fe intermetallic compounds (IMCs). The use of Cu-Mo interlayer successfully prevented the mixing of Ti and Fe to avoid the formation of FexTiy brittle phases. Near Ti-(Cu + Mo) interlayer boundary typical CuTi2, CuTi and Cu3Ti2 phases are formed. Intermetallic stoichiometry, morphology are discussed. The tensile strength of the Grade1/316 L joints with the Cu-Mo interlayer is 175 MPa, and the joints exhibited the ductile–brittle fracture. The fracture region formed at the interlayer along the molybdenum particles.