Microstructure and properties of Cu/Ti laser welded joints

Microstructure and properties of Cu/Ti laser welded joints. The optical microscopy, SEM, EDS, XRD and TEM were applied to assess the microstructure and bonding mechanism of Cu/Ti joints. When the laser beam was used to irradiate the copper side with an offset value of 0.45 mm, the welded metal and fusion line of Cu side were mainly consisted of the Cu solid solution. The intermetallic layer was formed at the titanium-welded metal interface. The thickness of IMCs was about 25 μm and consisted of the Cu solid solution, intermetallic compounds such as TiCu, TiCu2, Ti2Cu and Ti3Cu4. The tensile strength of butt joints could reach 151 MPa, i.e. 61% of the tensile strength of the copper base metal. The quasi-cleavage fracture occurred at the IMCs.