Molécula H2


The H2MAT project chiefly aims to design, manufacture and assess multilayer structures, High-Entropy Alloys (HEAS) – steel-interface, as an alternative to the limitations of steel stainless currently used in hydrogen carriers.



the physical and chemical nature of the HEA-steel interface to act as a barrier to hydrogen diffusion into steel, including the introduction of extrinsic materials, i.e. copper alloys or others.


against hydrogen of non-conventional HEAs, both iron-based and copper-based, as well as compatibility of the former with steels.


to produce hybrid joints with controlled interfaces and in such a way as to minimise carbon diffusion into the HEA during processing.


compared to using current stainless-steel structures in Hydrogen transport, as well as their potential use in cryogenic conditions or other Hydrogen-rich environments.


To move towards a future where hydrogen can be used efficiently as an energy source in various end uses, it is necessary to design and optimise both the materials and their manufacturing to withstand the conditions at which they will be exposed. For all those reasons, H2MAT proposes:

Infografia HEA Interfase acero

The development of new materials that withstand and reduce hydrogen diffusion

The steels currently used do not have good properties in hydrogen-rich environments, and may even become brittle in extreme cases, unlike HEAs.

That is why H2MAT wants to test if it is possible to extend the useful life of steel by coating steel with HEA, without the need to oversize the pipes. The development of HEA-only pipes does not seem economically viable in extensive applications, even if the most common alloy, Cantor, is used. Specific applications, such as aeronautical, are a potential field to be explored.

Another field of technological development is the creation of a HEA and steel interface that avoids carbon diffusion from one material to the other. The literature available suggests that in the presence of this element, the embrittlement tendency not only of steel, but also of Cantor alloy increase. The impact of carbon on other HEAs to be used in this project is also to be explored.

As shown above, different combinations of materials will be analysed and their behaviour in contact with hydrogen will be studied for their future use in hydrogen transport. The aim is to achieve the following:


  • Reduced weight of the material used.
  • Reduced densities of steels.
  • Cut down on costs.
  • Manufacture higher quality pipes.
  • Analyse the possibility of exporting the combinations to other sectors such as the aeronautical sector.

Consider hybrid systems with different materials to functionalise equipment and thus be able to ensure low diffusion, long equipment life and lower cost per component.

Throughout the project, different hybridisation technologies of HEA – Steel – Interface layers will be analysed and tested to see how the bonds are shared.


Co-melting (TECNALIA and AZTERLAN)

Co-melting technology is based on the use of metallic or ceramic grafts to improve the final properties of the parts obtained, and in particular, wear resistance or mechanical properties.

The process begins when the graft(s) is(are) placed in the mould cavity. The mould is then closed and molten metal is poured in.

Metal covers part of the graft which becomes embedded, and depending on the materials used, metallic continuity can be obtained between the graft (metallic, in this case) and the part, or simply the graft is embedded in the metal by the force generated in the contraction that occurs during solidification.

As a result, the metal part with specific reinforcements obtained achieves a reduction of the final weight of the part and increases its mechanical and wear resistance properties.


NSF (Near Solidus Forming) (near melting point) (MONDRAGON UNIVERSITY)

The Near Solidus Forming (NSF) manufacturing process consists of solid material forming at very high temperatures (near melting point) and in a closed volume. Those high temperatures provide the material with high ductility which together with the closed volume tooling, allow complex metal parts to be obtained with lower energy and raw material costs compared to other similar processes.

Furthermore, the mechanical properties of the components are equivalent to those obtained in hot forging. In addition, and based on previous experience, this process also seems an ideal method for joining the dissimilar materials considered in the project.

The very high temperatures used in the process allow for greater interaction between the materials which combined with the deformations/pressures generated, make it possible to achieve very good joints by diffusion of elements present (equivalent to an even better than those obtained by Friction Stir Welding (FSW).

Diffusion Bonding by HIP (Hot isostatic pressing) (CEIT)

Diffusion bonding or diffusion soldering is a solid-state welding technology that produces coalescence between two contacting materials under high temperatures and specific pressures. Solid-state diffusion HIP welding differs from other solid-state welding techniques by providing a strong, dense weld joint with stability properties despite the area and configuration of contact surfaces of welded materials. Depending on the materials to be joined, it may be necessary to apply an intermediate layer to promote diffusion and thus bonding between the two parts, or to limit the diffusion of some alloying elements of the components to be joined, and to avoid build-up of brittle compounds in the interface. Furthermore, it is possible to accelerate or slow the diffusion rate by increasing or decreasing the HIP temperature and/or pressure and thus prevent nucleation and growth of undesirable phases in the contact area.

Diffusion Bonding mediante HIP (Hot isostatic pressing) (CEIT)

Expected results


To gain a better understanding and control of the physical-chemical nature of HEA-steel interface, so it can act as a hydrogen diffusion barrier.


The ability to propose material combinations with a better performance against hydrogen embrittlement.


Assessment of extreme technologies in order to propose optimised processing parameters.

Technical-economic assessment for the viability of the use of the materials developed in this project.
Development of tests to validate hydrogen embrittlement and permeation in the resulting hybrid materials.
Breakthrough in the field of thermodynamic modelling (CALPHAD), both in hydrogen bonds and diffusivity in multilayer structures.

Main indicators

indexed scientific journal
EPO and PCT patent applications


Esquema h2mat

The project CONSORTIUM consists of several participants

This project is coordinated by MONDRAGON UNIVERSITY and will involve the participation of seven other partners from the Basque Science, Technology and Innovation Network, namely: AZTERLAN, CEIT, SIDENOR I+D, TECNALIA, TUBACEX INNOVACIÓN, UPV/EHU and the BASQUE ENERGY CLUSTER.

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