Influence of filler metal on microstructure and properties of titanium/copper weld joint by GTAW weldments.

Gas tungsten arc welding (GTAW) is a widely used joining technique due to its low welding cost and flexible process. To promote the application of titanium/copper dissimilar metal welded structure, the microstructures and properties of TA2 titanium and T2 copper butt joint prepared by GTAW with pure copper filler metal (S201) and Cu–Al filler metal (S214) were systematically investigated. The microstructures of the joints were analyzed by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS), and the properties of the joints were evaluated by tensile, microhardness and electrochemical corrosion tests. The results suggested that the intermetallic compound layers of S201 filler metal weld joint were composed of rod-like Ti 2 Cu, plate-like TiCu, needle-like TiCu and a small amount Ti 3 Cu 4. While plate-like TiCu were not found when using S214 filler metal. Moreover, the weld joint with S201 filler metal displayed a better plasticity and a higher tensile strength having 73.0% tensile strength of copper base metal. The electrochemical corrosion tests indicated that Al elements in weld joint with S214 filler metal could inhibit the cathodic reaction, and decrease the dissolution of weld seam metal. [ABSTRACT FROM AUTHOR]