Abstract
Recently, the demand for dissimilar metal joints of titanium to aluminium alloy has arisen in industry, especially in the transportation vehicle industry. However, it is well known that fusion welding of titanium to aluminium alloy is difficult because of generating the brittle intermetallic compound at the joint interface. Therefore, new welding processes with high reliability and productivity for these dissimilar materials are demanded. In the present work, Laser roll welding of titanium to aluminium alloy using a 2 kW fibre laser was tried to investigate the effects of the process parameters on the formation of the interlayer and the mechanical properties of the joint. As a result, the cross-section of the joint shows partial melting of the aluminium sheet and spreading of molten aluminium alloy on the titanium sheet occurs during the welding thermal cycle. Various types of intermetallic compound were confirmed at the interlayer of the welded joint. The specimen with a bonding width of 2.8 mm failed in the base metal of titanium in the tensile shear test. In Erichsen cupping tests, the Erichsen value was 5.7 mm. This value was 89% of the base metal of aluminium sheet.
Acknowledgements
This study is part of the research and development of new industrial systems using lasers and development of new high-strength, high-functionality members, selected as a New Regional Consortium Research and Development Project by the Ministry of Economy, Trade and Industry and we would like to express our gratitude to all involved at the Chubu Science and Technology Centre, Mie University, Lazerx, Chuo Seiki, Horie Metal Industries and Daido Metal Industries for their kind assistance.