Currently, aircraft industry uses complicated and cost intensive forming processes to shape complex titanium (Ti) sheet components, such as deep drawing, hot forming, super plastic forming (SPF) and hydro forming. In some cases, parts are even obtained by hand working. These techniques show severe drawbacks which include high costs, long industrialisation phases and high energy consumption rates.
The INMA project aims at developing an intelligent knowledge-based flexible manufacturing technology for titanium shaping that will lead to drastically reduce current aircraft development costs incurred by the fabrication of complex titanium sheet components with a minimal environmental impact. In particular, this project aims at strengthening European aircraft industry competitiveness, by transforming the current non-flexible and cost intensive forming processes into a rapid and agile manufacturing process. This brand new technology, based on Asymmetric Incremental Sheet Forming (AISF), will transform the way many titanium sheet aeronautical components such as after pylon fairings, fan blades, exhaust ducts or air collectors are manufactured today. The innovative, cost-efficient and ecological forming technology to shape complex geometries in titanium that will contribute to strengthen the European aircraft industry competitiveness meeting societies needs.
The main features of the innovative AISF technology to be developed will be an increased flexibility, cost reduction, minimised energy consumption and a speed up in the industrialisation phase.
The major impacts of the results obtained in the INMA project will be:
- Cost incurred by dedicated tooling will be reduced in a 80%;
- The component lead times will decrease in a 90%;
- Buy-to-fly ratios will be up to a 20% lower.
The INMA Consortium consists of end-users, an equipment provider, research organisations, universities and the EASN association. Participation of industrial partners who will directly exploit the project results will guarantee the impact of the project.
Simplified forming of difficult materials
The aerospace industry is under heavy pressure to reduce costs, time and energy consumption associated with aircraft manufacture. Optimisation of novel sheet-forming technology could provide the solution for hard-to-form titanium (Ti) alloy parts.
Conventional sheet metal processing methods are time and energy intensive, particularly for hard materials like Ti alloys and complex parts. Further, manufacture requires dedicated tooling. Development of technology based on asymmetric incremental sheet forming within the EU-supported project 'Innovative manufacturing of complex Ti sheet components' (http://www.inmaproject.eu/ (INMA)) will facilitate production of complex metal parts without dedicated tooling. The savings in time, energy and cost together with the added flexibility will significantly strengthen the competitive position of the EU aerospace industry.
Asymmetric incremental sheet forming is a relatively new computerised processing technique based on an older localised deformation processing method. A computer numerical control-driven tool forms the asymmetric sheet metal part in a stepwise fashion without the need for costly supporting dies. Thus, the final part is produced from a series of localised deformations.
Scientists focused on the Ti alloy Ti6Al-4V. Experimental activities to determine processing parameters were supported by finite element modelling to simulate hot and cold forming of large and complex shapes. After characterising the deformed alloys and applying advanced data mining techniques, researchers optimised the tool path to reduce distortion and increase geometrical accuracy.
Two technology demonstrators showcased the benefits of this innovative technology. The team employed Inconel 718, a nickel-chromium-iron alloy, to produce a strut half with cold forming. A strut is a shock-absorbing bar supporting the wing or landing gear of an aircraft. Ti6Al-4V was used to produce two generic shapes similar to pylon fairings, aerodynamic covers over the pylon that attaches the engine to the wing or fuselage. The Ti was formed with a hot die-less forming process. Preliminary evaluation confirmed good geometric accuracy and overall quality of the parts, putting the technology on the road to commercialisation.
INMA has made an important contribution to knowledge-based flexible manufacturing through process development and materials characterisation for difficult-to-form sheet metal. This technology has the potential to revolutionise sheet metal forming and INMA has made sure the EU aerospace sector will be among the first to benefit from industrialisation.