Lightweight wear-resistant panels and protection panels were developed to a level of technological readiness for manufacture of the elements in agreed sizes. Welding tests, definition of welding parameters and basic mechanical tests were carried out by Aalto University. The lightness of the panels opens up new possibilities for applications where weight reduction or portability needs to be combined with a wear-resistant surface.
Two new commercial application were launched based on the research results: new protection panel for advanced ballistic protection needs offering superior resistance to explosions and ballistic threats, and wear resistance container floors that developed in close cooperation with customers.
A hybrid joining method was developed enabling the creation of hybrid joined lightweight panels for building industry. Usually the joining of corrosion-resistant coated materials is challenging as welding is unsuitable for most applications because it destroys the protective coating. In addition, airtightness of the joints and high stiffness of the product have be guaranteed. The developed hybrid joining method is based on clinching and adhesive bonding that resulting in stiff, lightweight and airtight panels. The solution to the joining technology enabled the development of a new concept, intermediate floor structure, and to integrate functionalities into the end product. The new concept was developed in RFCS Zemusic-projectand it acts as a part of the building ventilation and heating system, as well as a zero-energy solution. Cooperation with RFCS Zemusic-project and several international research institutes and industrial partners has been in an important role in achieving the results.
In manufacturing competitive products, the complex demands associated with short lead-time, maximum cost-effectiveness and high quality need to be balanced against those of durability and structural integrity. Increasing importance has been attached in recent years to reduced energy consumption, total life-cycle assessment and environmental footprint issues, leading many manufacturers to select lightweight designs incorporating high-strength materials, and to adopt new approaches to production engineering. These demands for higher structural performance have brought a corresponding increase in the strength requirements for materials used in structural applications. The choice of structural materials that can be manufactured has been continuously widening, with sandwich-type or other thin-walled structural alternatives replacing thicker plate in some demanding load-bearing applications, and implementation of various forms of multi-material structures. The effective application of novel material technologies brings a clear competitive edge in metal and engineering industry.
The solutions developed for ultra-high-strength steels and hybrid materials enable the design of new lightweight components with optimized properties; benefits are obtained over the whole life time of the product in terms of reduced energy consumption, reduced emissions and improved performance with integrated functionalities.This provides strategic advantage and, in the current market turbulence, a way of standing out from the competition. The lighter weight of the full-metal sandwich panels creates new possibilities for applications where weight reduction or portability needs to be combined with a wear-resistant surface. The solutions have found applications in very different fields; the rigid and lightweight high-strength steel panels are used for various structural purposes ranging from freight container floors to special modular panic rooms. Commercialised protection panels have been already announced by Ruukki.
On top of this, however, the extensive elementary knowledge gained means there are several other potential applications on the horizon. The programme has brought a significant increase in knowledge concerning the relationship between processing routes for hybrid, composite and sandwich materials and their mechanical performance, and on the application of high-strength steels and hybrid materials in lightweight structures. The results may be far-reaching, with the final impact being shown over the next 2–5 years through commercialisation of the results obtained.
Sami Nummela, SSAB Europe Oy
Metso Minerals Oy, Rautaruukki Oyj, Aalto University, Tampere University of Technology, HAMK University of Applied Sciences, Bostik Oy, BTM Scandinavia Ab, Tohoku University, RFCS Zemusic-project and RWTH Aachen