Product Code: PIC2008_P107

Single Mode Fibre Laser Welding of Dissimilar Aerospace Alloys
Authors:
Andrew Pinkerton, The University of Manchester; Manchester Great Britain
Hui-Chi Chen, The University of Manchester; Manchester Great Britain
Lin Li, The University of Manchester; Manchester Great Britain
Presented at PICALO 2008

Preventing the formation of brittle intermetallic compounds and defects or porosity in the fusion zone is a major challenge when welding dissimilar materials. Additionally, differences of physical properties between two joined materials generate thermal expansion mismatch stresses on cooling which means these weaknesses can quickly lead to failure. Welding research has not yet fully overcome these problems. In this study, Ti-6Al-4V titanium alloy and Inconel 718 nickel alloy were joined together using an IPG 1 kW single mode fibre laser and each sample evaluated in terms of extent of the fusion and heat affected zones, composition, microstructure, corrosion performance and mechanical properties. The effects of the process parameters of laser power, welding speed, focal position of laser beam and beam offset from the centre of the bond on the samples are evaluated. It is found that the formation of the welded region influences characteristics significantly and the types of narrow fusion zone uniquely possible with the fibre laser can be advantageous for this process.