In a development with The Boeing Company, TWI worked with Aeromet in the UK to develop a low-cost titanium structure by the use of laser welding and subsequent hot forming.
Laser welding offers a number of advantages over other welding processes, including low distortion and high joint completion rates. In addition, the smaller molten pool makes shielding and control of oxidation easier in atmosphere with local shielding.
By coupling hot forming with the laser welding process, simple net thickness plate and sheet structures can be welded and then hot formed to bend the structure to its finished complex shape and simultaneously stress relieve the structure. This provides a repeatable product in an inert condition.
TWI developed a technique to Nd:YAG laser weld a titanium structure (see attached figure), meeting the Class A acceptance criteria of AWS D17.1 before Aeromet subsequently hot formed the structure meeting the dimensional requirements set by Boeing.