Objectives and content
Aluminium alloys have many useful properties which are exploited widely in industry. Their main attribute is the high strength to weight ratio which allows major reductions in operating costs in transport systems. Other useful properties which the materials possess are high corrosion resistance leading to their use in products such as door and window frames and their high thermal conductivity making them suitable for applications such as heat exchangers. The major barrier to the more widespread utilisation of aluminium alloys is their low weldability which means that mostly mechanical fastening methods have to be used or joints using weldments have to be substantially reinforced incurring a weight penalty.
Consequently, the main objective of this project is to improve welding technology of aluminium to a level to enable it to be used in place of current mechanical fastening methods, or to improve the performance of current weldments and allow a weight reduction. To achieve this the partners will investigate two new welding techniques, a novel pretreatment process and two process stabilisation methods. These can be summarised as:
- New welding techniques,
- Deep conduction welding using a high average power CO2 TEA laser. - High average power combined cw+ shaped pulse Nd-YAG laser welding. - Laser deoxidation for both TIG welding and Nd-YAG welding - Process stabilisation techniques.
- Keyhole stabilisation for Nd-YAG welding.
- Very low power laser stabilised TIG welding.
These techniques will be supported by optimised joint designs and theoretical modelling for deformation prediction. The expected achievements of the project will be industrial realisation of the new process(es) by applying them to the following industrial components, - air conditioning and electrical services ducts within a railway carriage, - aircraft fuselage stiffened panel, - air conditioning pipe for aerospace applications, - secondary structural wing component (shroud box). The impact of welding for these components will be a significant weight reduction (typically 15%) and considerable savings in manufacturing costs.
The consortium comprises three industrial users and developers of the technology (British Aerospace, Aerospatiale and Fiat), a specialised laser research institute (IREPA), a laser manufacturer (Quantel) and two universities (Lappeenranta and Essex).
Funding SchemeCSC - Cost-sharing contracts
10043 Orbassano Torino
67400 Illkirch Graffenstaden
91941 Les Ulis
CO4 3SQ Colchester