Page 7 - Research and innovation In advanced materials with application to the railway sector

In the case of composite components and multimaterial structures, it is equally critical to
develop new mechanical, adhesive or hybrid joining technologies, to optimize the joints and
ensure their correct behaviour throughout the lifetime of the component.

Also related to maintenance, developments in inspection techniques, damage tolerance and
repairability of composite materials are critical. In addition to the aspects discussed on
sensor integration, innovation is essential to improve the out-of-plane behaviour of
laminates, with technologies that add fibres through thickness such as “Tufting” or
“Stitching” or technologies that allow automatic repair, in situ, of thermosetting or
thermoplastic matrix composites, with automatic taping and out-of-autoclave curing.

In the field of metallic materials, conventional to varying degrees, the technologies for
repairing damaged components by means of automated welding or additive manufacturing,
in all its variants, with different heat sources and types of material supply (WAAM, LMD,
EBAM, etc.) are also of great interest.

ENERGY

Innovation in advanced materials is also a fundamental variable for the adoption of new
energy sources, a trend to which the railway sector is also contributing. In this sense, there
have been developments in materials for components capable of managing and harvesting
energy from different sources in an integrated way, whether they be internal sources of
energy (heat, vibration, etc.) or external (solar, temperature gradients, etc.). This section is
related to the aforementioned multifunctionality (integration of photovoltaic cells in
surfaces and windows, systems for “Energy Harvesting”, or energy storage in structural
components, etc.)

In addition, everything related to hydrogen storage technologies as an energy vector is
especially relevant nowadays.

 Materials for pressurized tanks (up to 700Bar) for hydrogen storage.
 Materials with high mass and volumetric hydrogen absorption capacity (MOFs,
ultra-porous carbon-based materials, metal hydrides)

SUSTAINABILITY, RECYCLABILITY AND LIFE CYCLE

The contribution of innovation in advanced materials to the search for more sustainable
solutions is evidenced, among others, in:

 The need to eliminate and replace critical materials.
 Promotion of the circular economy, with recycling, reconditioning or reuse of
materials, such as the use, in coatings or in additive manufacturing processes of
parts and components, of dust from the atomization of railway scrap.
 Developments in technologies for the recovery of non-metallic materials.
 Development of reversible joining systems for thermoplastic materials or
composite-metal joints (ultrasound, induction, and electric resistance).
 The development of biodegradable fibres and reinforcements.

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Position paper: Research and innovation in advanced materials with application to the railway sector
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