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Mercato interno, industria, imprenditoria e PMI

New Affordable Stainless Steel for extreme Conditions

Objectives of the commitment

Critical parts of aircrafts, such as landing gear components used in extreme conditions, require materials presenting the highest performances. They are currently either titanium alloys (metal on which Europe is import dependent) or high resistance steels, with surface coatings for corrosion resistance purposes. These coatings, presently cadmium or chromium based, are detrimental to the environment. The objectives of the project, proposing a substitute solution with improved performance and longer lifetime, which is based on special stainless steel grades with intermetallic hardening precipitates, are twofold:
• To demonstrate the reliability of the vacuum melting process in order to ensure the qualification of this new material for safety parts. Melting is a key factor to succeed in developing these steels, containing hardening elements that can form non-metallic inclusions.
• To adapt the vacuum melting process in order to recycle the scraps produced when manufacturing and machining parts, and to reach affordable cost with a short recycling loop.

Description of the activities

The activities of the project are aiming at developing, with the target of landing gear parts, the technology readiness level (TRL) of the “high-resistance-stainless-steels” from level 3 to level 5 or 6 for the melting process, by demonstrating the reliability and the robustness of the industrial melting process for low and high levels of returned scraps:
• High resistance stainless steels grades have been patented by Aubert&Duval (subsidiary of ERAMET) and developments have been achieved with Messier-Bugatti-Dowty to reach TRL4 with one of the grades (MLX19™, minimum Ultra tensile Strength-UTS 1800MPa)
• Aubert&Duval has started the development of a second grade, with higher UTS performance, presently at TRL 2 to 3. This second grade exhibits enhanced performances using similar design concepts and processes.
• Non-European competitors are developing stainless steels for the same applications as well (Custom465™ & Custom565™ from Carpenter).
• Airbus UK has launched a development program with the objective to be able to put on an experimental aircraft a landing gear manufactured in stainless steel. Airbus UK will gain experience with stainless steel grades.
• The high performances of these alloys are obtained with intermetallic precipitates NiAl or Ni3Ti; but the so called “hardening elements” Al and Ti can form during the melting process some non-metallic inclusions, even with the vacuum induction melting process used (VIM) and the refining by vacuum remelting (VAR).
• The cleanliness (absence of non-metallic inclusions) of these grades requires specific conditions for the melting and refining processes; the improvement and the reliability of these processes become a key factor for further developments of these steels.
• The high amount of scraps generated when parts are manufactured (flying weight of such parts represents less than 10% of the raw material introduced in the melting process) represent a very high potential to save virgin materials, if these scraps can be directly used in the vacuum melting process.
• Cost affordability can be achieved by developing the recycling capability of the melting process.
The work program is defined in order to demonstrate the quality of the alloys melted in Europe and the reproducibility of the melting process, adapted to this family of new steels. Several industrial melts (8 in total equivalent to 12 tons each) have to be performed in order to establish a robust melting route in terms of quality management. The main criteria of quality are the steel cleanliness and the homogeneity of the metallurgical structure and properties obtained in the ingots at the end of the melting process. The subsequent steps of the transformation process of the ingot to the parts are less critical and will need subsequently a more usual industrialization process.
The planned tasks will be focusing on the vacuum induction melting process (VIM) and on the assessment of the quality of industrial ingots after a first step of conversion into billets in order to be able to measure the cleanliness and its consequence on mechanical properties, fatigue performances and corrosion resistance. The properties and main characteristics required to prepare the certification process of the new steels will then be assessed.
The work is organized in 3 work packages which will require close interaction between one another and involve at least 2 players in each work package:
• Work package 1 : Melting process optimization
• Work package 2 : Ingots cleanliness assessment
• Work package 3 : Material properties validation

Description of the expected impacts

• New material for extreme conditions
A successful project will offer alternative solutions exhibiting higher performances for applications in extreme conditions such as landing gear of aircrafts or other structural parts. The TRL of these solutions will reach the level 6 for the melting process, allowing further certification of the material.
• Sustainability
The new material will replace non stainless steels, avoiding coating technologies with detrimental effects on the environment (presently hexavalent-chromium and cadmium, or other electrochemical processes in the future).
The development of a VIM process, suitable for recycling these materials, without loss of their added value, will allow a drastic decrease in the consumption of high purity raw materials and will contribute to a circular economy process.
The durability of stainless steel parts will be quite higher and will have a very positive impact on the service value offered to the airlines, representing here the end user.
• Strengthening the European industry
It will provide competitive advantages for all the supply chain of parts requiring high performances steels, and it will strengthen the position of the European industry and of the metallurgy industry by:
o avoiding imports of titanium alloys or titanium sponge,
o developing processes capabilities to reach higher quality levels for special steels,
o implementing a short recycling loop for a manufacturing chain to reach affordable costs with these new alloys, and to increase its competitive advantages (it will reinforce the position of these steels against titanium as well)
o offering high performances materials with potential applications on other markets, where very high characteristics and corrosion resistance are both needed (other structural parts in aeronautic, mechanical equipment…).

Coordinating organisation & role

Name of the coordinating organisation: Aubert & Duval (ERAMET GROUP)Country: FranceEntity profile: Private sector - large companyRole within the commitment:

1/ Coordination of the program
2/ Performing 8 melts of about 12t each in vacuum furnace, using virgin or recycled raw materials including ingot conversion with open die forging (Work package 1)
3/Sampling of materials in the produced bars for:
• First assessment of the material quality with standard industrial procedures and criteria to compare various melts and define further assessment criteria with the other partners
• Supplying the 3 other partners with test materials for characterization planned in Work package 2 and 3.

Other partners

Fraunhofer-Gesellschaft zur Förderung der Angewandten Forschung e.V.

Name of the organisation: Fraunhofer-Gesellschaft zur Förderung der Angewandten Forschung e.V. Country: Germany Entity profile: Governmental/public body
Role within the commitment: Fraunhofer will lead the CFRP and GFRP recycling research.
Fraunhofer will perform corrosion tests on the developed materials.
Fraunhofer will work with CIDAUT on the implementation, validation and refinement of LCCA tools for the project. Fraunhofer is the Quality Manager of the Consortium and will oversee deliverables and general reporting are produced with the best possible quality following agreed review standards.

Fundacion Cidaut

Name of the organisation: Fundacion Cidaut Country: Spain Entity profile:
Role within the commitment: CIDAUT will lead the research activities on materials recycling and compounding, implementing lab scale demonstrators of each process at its premises and, later, supporting end-users upscale the processes.
CIDAUT will perform mechanical tests, microstructural analyses, injection moulding capability studies on the developed materails, and will work with Fraunhofer on the implementation, validation and refinement of LCCA tools for the project.

RWTH Aachen University (Institute of plastic processing (IKV)

Name of the organisation: RWTH Aachen University (Institute of plastic processing (IKV) Country: Germany Entity profile: Governmental/public body
Role within the commitment: RWTH will implement the novel 3D Generative Preforming process (3D Fibre Spraying) that enables to create high-value long fibre-reinforced 3D preforms for thermoplastic and thermoset composites at low process costs (different kinds of yarn as a raw material, low tooling costs due to low cavity pressures). This cost effective technology allows to align the sprayed fibres in order to produce high-performance, engineered anisotropic products.

Universita' di Cagliari

Name of the organisation: Universita' di Cagliari Country: Italy Entity profile:
Role within the commitment: University of Cagliari is one of the leading European organization in the resin design and coupling with thermoplastic and thermose materials. University of Cagliari will support in the definition of the composite materials, both from CFRP/GFRP, ABS and Rare Earth composite material.

Relight

Name of the organisation: Relight Country: Italy Entity profile: Private sector - SME
Role within the commitment: RELIGHT will work with ITRB to provide the research partners with residues for the recycled ABS supply and the REE recovery processes, including their HydroWEEE process as part of the processes to be studied and analyzed.

Piaggio Aerospace

Name of the organisation: Piaggio Aerospace Country: Italy Entity profile: Private sector - large company
Role within the commitment: Piaggio Aerospace is one of the project End Users (Aeronautics Industry): as such it will provide requirements and further applications that could be developed with the Consortium Materials. Piaggio will assist in the compounds selection, provide Fraunhofer with specific corrosion requirements on business jet size aircraft, and will assess that the developed materials performance fits the selected applications desired improvements.

Blackshape Aircrafts

Name of the organisation: Blackshape Aircrafts Country: Italy Entity profile: Private sector - SME
Role within the commitment: Blackshape Aircrafts is one of the project End Users (Aeronautics Industry): as such it will provide requirements and further applications that could be developed with the Consortium Materials. Blackshape will support to fulfill the requirements of the aeronautics industry on ultra light jet, light jet and trainer for Syllabus, and will assess that the developed alloys performance fits the selected applications desired improvements.

KU Leuven

Name of the organisation: KU Leuven Country: Belgium Entity profile: Academia
Role within the commitment: KUL will collaborate on the balance problem studies and will lead the rare earth recovery research with the solvometallurgical and ionometallurgical processes.
KUL will also contribute to the final compounding selection.
KUL is the Dissemination Manager of the project, promoting that all partners are active on the project Dissemination.

FIDAMC

Name of the organisation: FIDAMC Country: Spain Entity profile: Governmental/public body
Role within the commitment: FIDAMC is going to lead the Work Package on Compression Moulding with CFRP-enhanced materials. As part of the AIRBUS Group, FIDAMC will also be able to provide the input material.
FIDAMC successfully developed a 3D Printer of own design to serve the Aerospace Industry and will be supporting Smart Lab 3D Industries in its 3D printer design.

COMPOSITE INNOVATION CENTER

Name of the organisation: COMPOSITE INNOVATION CENTER Country: Canada Entity profile: Governmental/public body
Role within the commitment: Composite Innovation Center is one of the world leading organization in the field of Composite materials, both from carbon fiber and vegetal-based fibers.
Composite Innovation center has successfully implemented, at lab-scale, recycling processes for CFRP and GFRP.

Existing EU Contribution: No

Period to implement the commitment: from 01-11-2014 to 31-10-2017