Mechanical and microstructural properties of stainless steel/titanium joints made by dynamic diffusion welding

Due to a good relation between mechanical properties and density, combined with excellent corrosion resistance, titanium and its alloys have many applications in the chemical, petroleum, aeronautical and nuclear industries. However, the use of this metal is limited by relatively high cost connected with problems of welding to other materials such as austenitic stainless steels. Ti/Fe, Ti/Ni and Ti/Cr equilibrium diagrams anticipate the formation of several intermetallic compounds, with eventually, for the steel/titanium pair, the formation of titanium carbide (TiC). Dynamic diffusion welding (DDW) combining induction heating with the application of dynamic pressure, enables, while retaining the advantages of conventional diffusion welding, considerable reduction in process time and therefore in the thickness of brittle intermetallic compounds, and improved mechanical performance. This study describes the optimisation of the parameters for this welding method and identifies the constituents formed in the diffusion zone. X-ray diffraction and backscattering electron detecting micrography is used to characterise the joints. Materials include (X 2 CrNi 18-10) steel and titanium T50 alloy