Two pass laser welding of 304 stainless to TC4 titanium alloy using monel 400/Nb bilayer

Abstract

Laser welding was performed to join 304 stainless steel (SS) and TC4 Titanium (Ti) alloy using Monel 400/Nb bilayer. In order to avoid the formation of Ti-based and Nb–Fe intermetallics, two pass welding involves creating two fusion weld separated by unmelted Monel 400 and Nb interlayer. The first laser pass was focused on the 304 SS side, a weld zone of the mixing of molten Monel 400 and 304 SS was formed. The second laser pass was focused on the TC4 Ti alloy side, a weld zone of the mixing of molten Nb interlayer and TC4 Ti alloy was formed. The joining between the Monel 400 and Nb interlayer was achieved by atoms interdiffusion. The joint fractured at the Monel 400-Nb interface with maximum tensile strength of 258 MPa.

Keywords

• Welding
• 304 stainless steel
• TC4 Ti alloy
• Bilayer
• Interface
• Tensile strength