Riveting has been the state of the art of joining technology for aircraft structures since decades. The necessary overlap joint demands a large amount of material which restricts weight savings. Furthermore, the riveting process is quite intensive in process time. The LIGHTWELD project aimed at developing and adapting LBW and RSW for newly developed more weldable light alloys with the objective of:

• Reducing weight through replacing the use of vast amount of rivets
• Enabling the automation of joining and NDT processes for decreasing process time

The project addressed the comparison of novel welding and conventional riveting processes in terms of fatigue and corrosion performance as well as environmental impact and manufacturing cost enabling the advance towards lightweight and eco-efficiency objectives. Project specific goals were related to:

• Development of robust and optimised LB, RS and FSS welding for the joining Al-Li and Mg;
• Reduction of component weight between 5 and 10%;
• Reduction of operation cost until 20%;
• Corrosion resistance improvement for example by means of new joint designs;
• Inspection time saving due to the possibility of automating that process;
• Knowledge generation in the field of dissimilar joining of Al-Li and Mg alloys; and
• Fabrication cost saving compared to aero-structures made of composite materials.

The singular characteristics of the materials to be welded and weldability problems related to dissimilar metal joining make mandatory big knowledge and expertise, which were in this case provided by IK4-LORTEK as something essential for the good end of the LIGHTWELD project.

The LIGHTWELD project advanced the welding technology for studied alloys, making it cost efficient and feasible for industry manufacturers of different markets. This will mainly open new manufacturing possibilities for European industry. Aircraft industry was the main target market, but other industrial areas were also to be considered in the future exploitation.