The use of intermediate inserts for CO 2 laser welding of steel AISI 321 and a Grade 2 titanium alloy

The paper studies the structure, chemical and phase compositions, hardness and strength of welded joints obtained in AISI 321 steel and Grade 2 titanium alloy sheets by CO 2 continuous laser with the use of intermediate Cu, Ni and Ag-Cu-Zn alloy inserts. It is demonstrated that the maximum strength of welded joints is achieved by the welding conditions enabling one to form multiphase structures with intermetallics in the material of a weld, rather than only those based on solid solutions. © 2018 Author(s)

EBSD analysis of the structure of a weld joining a chromium-nickel steel sheet and a titanium alloy sheet through a copper insert

The structure of the different zones of a C02 laser welded joint between a chromium-nickel steel sheet and a titanium alloy sheet, with a copper insert between them, is studied by EBSD analysis. The phase compositions of all the zones have been determined. The weld material has been found to consist of a Cu-based solid solution and unevenly distributed intermetallic particles of different stoichiometric compositions. The heat-affected zones consist of supersaturated iron- and titanium-based solid solutions. After laser welding, the microdeformations of the phase lattices are distributed unevenly over the cross section of the welded joint; namely, the maximum microdeformations and the resulting microstresses are concentrated in the heat-affected zone at the boundary between the weld and the titanium alloy. © 2019 IOP Publishing Ltd