Abstract:
Objective Welding of copper/titanium dissimilar metals has important potential application prospects in aerospace, nuclear industry and other fields. The purpose of this paper was to realize connection between copper (T2) and titanium (TA2).
Methods Welding procedures test of copper/titanium dissimilar metals was carried out by laser welding. Macroscopic morphology, microstructure and mechanical properties of welded joints under different laser powers were analyzed.
Results The results showed that effective connection of copper/titanium welded joints could be realized by laser welding. Welded joints presented the form of welding-brazing, which was composed of heat affected zone on the copper side, fusion zone and heat affected zone on the titanium side. When laser power was 1.8 kW, tensile strength of welded joints was 127.2 MPa, which was about 53% of copper base metal. Minimum microhardness was on the copper side, and fracture occurred on the copper side. With the increase of laser power, Cu-Ti intermetallic compound with thickness of about 34 μm was formed at the welding-brazing interface, making it a weak point in welded joints.
Conclusion Reasonable control of laser power could effectively inhibit formation of intermetallic compounds and improve mechanical properties of welded joints. These findings not only provided valuable reference for laser welding of copper and titanium, but also provided important experimental basis for further optimizing design and manufacturing process of dissimilar metal welded joints.