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Cost Effective Integral Metallic Structure

Final Report Summary - COINS (Cost effective integral metallic structure)

The principal objective of the COINS project was to extend the application of integral metallic structures using Friction stir welding (FSW) by advancing the state of the art of FSW technology, developing new geometries of FSW and applying innovations in structural design.

The project was organised in six independent, yet interrelated, Work packages (WPs) which undertook the following tasks:

1. FSW standards' determination and testing, focussing on the production of relevant documents to provide guidance to all partners on data that had to be recorded and test standards to be used. A Welding procedure specification (WPS) was developed as a consistent means for data exchange between project partners.
2. Design of a cost effective integrated metallic structure, which investigated sophisticated design solutions taking advantage of the potential cost and weight savings whilst locating the weld within the structure so that the modified weld mechanical performance could be best exploited.
3. Development of new applications, including dissimilar alloy joints, new joint geometries, welding extrusions followed by forming operations and fabrication of enclosed structures. The developed techniques were exhibited through the production of several demonstration components that included closed aircraft beam structure, semi-closed land vehicle hull and aircraft bulkhead and shear web.
4. Potential FSW repair applications during both the production and service processes. Processes for using FSW as a repair tool for general structures were also defined.
5. Investigation of potential combinations of FSW with other manufacturing processes, including bonding, mechanical fastening, pocketing and various forming methods.
6. Improvements to FSW processes through model development and fundamental understanding, primary process improvements, post-weld treatments and process monitoring and control of FSW.