Ongoing Projects
 Work Package 20A201: Thermoelectrics
 Work Package 20A401: AlCrFe coated, graded deep-drawing steels and duplex
 steels with enhanced corrosion resistance
 Work Package 20A402: CMA as combined structural material and catalyst
 for methane activation: REACAT
Completed Projects
 Work Package 20A101: Characterization of complex metal alloy behaviour under
 combined sliding friction and corrosion conditions (tribocorrosion)
 Work Package 20A102: Hydrogen storage in CMAs based on the intergrowth of
 CaCu5 and Laves phase structure types to combine high storage capacity with
 improved corrosion resistivity
 Work Package 20A202: Deposition of multi component thin films with
 composition gradient (PoP)
 Work Package 20A203: Coordinated characterization of Al-Cu-Fe PVD
 gradient coatings and their properties
 Work Package 20A204: CMA particles in alloys
 Work Package 20A301: Investigation of localized corrosion susceptibility and
 mechanisms of Al4(Cr,Fe) surfaces
 Work Package 20A302: Low-Loss Complex Magnetocaloric Alloys
 Work Package 20A303: Magnetic properties of CMA formed upon devitrification
 of Fe-based BMG
 Work Package 20A304: Reactive diffusion for the synthesis of CMA coatings
Work Package 20A101:
Characterization of complex metal alloy behaviour under combined sliding friction and corrosion conditions (tribocorrosion) |
WP Leader: Prof. J-P. Celis, Katholieke Universiteit Leuven |
Abstract:
The evaluation of the functionality of new materials to be used in a given set of industrial conditions is a challenging task. In the case of CMA, a major prerequisite is that the materials should not suffer from any surface degradation due either to dry or wet corrosion, and/or dry or wet wear. To that avail, a short term project was launched to develop a lab testing procedure allowing a rapid and comparative evaluation of the behaviour of CMA under combined wear and corrosion test conditions.
A novel protocol for the evaluation of the mechanical degradation and chemical/electrochemical re-growth of passive surface layers and resulting in the assessment of tribocorrosion, was developed based on sliding tests combined with electrochemical techniques. That protocol was applied on a known passivating material (AISI 316 stainless steel) and on complex metallic alloys (Al3Mg2, AlCuFeCr) produced by CMA-partners. The tested CMA materials form passive films and are shown to be susceptible to tribocorrosion. Their tribological behaviour depends on the thickness, porosity, and mechanical stability of the passive film.
A detailed description of that protocol has been recently submitted to TRIBOTEST for refereeing. A second publication on the evaluation of the tribocorrosion behaviour of CMA materials will be submitted soon for refereeing to WEAR. |
Work Package 20A102:
Hydrogen storage in CMAs based on the intergrowth of CaCu5 and Laves phase structure types to combine high storage capacity with improved corrosion resistivity |
WP Leader: Daniel Fredrickson, University of Stockholm |
Abstract:
Complex metallic alloys provide the opportunity to combine the structural features of several compounds with outstanding physical properties into a single phase with enhanced commercial applicability. Such is the case with the LaMg2Ni9-based hydrogen storage alloys: in these alloys, layers of the LaNi5 structure (CaCu5 type) are interleaved with layers of Laves phase-type connectivity. The result are phases that reflect both the high hydrogen uptake reversibility and corrosion resistance making LaNi5-based alloys the preferred material for NiMH batteries, and the higher storage capacities of the Laves phases. Variants of this compound are now being introduced by Sanyo as "superlattice alloys." We outline a project, set to begin this summer, searching for new LaNi5-Laves phase intergrowth alloys for hydrogen storage applications. The LaMg2Ni9 structure represents only one stacking sequence of LaNi5 and Laves phase layers. We will use quantum mechanical calculations to assess, systematically, the alloy and hydride stability of other stacking sequences, in which with the thicknesses of the layers are varied. From these calculations, targets for synthesis will be identified. Synthetic efforts, phase analysis and hydrogen storage properties measurements will then follow. A secondary objective of this study will be the analysis, through electronic structure calculations, of the role Co-doping plays in imparting corrosion resistance to LaNi5-based alloys, with the aim of finding low-cost alternatives. |
Work Package 20A201: Thermoelectrics |
WP Leader: Prof. Dr. S. Buehler-Paschen, TU Wien |
Abstract:
Within this Short Term Project (STP) a thermoelectric demonstrator employing Complex Metallic Alloys (CMA) as thermoelectric materials shall be developed and fabricated with the aim of demonstrating their potential for thermoelectric applications and of interesting future industrial partners. The selected materials are representatives of the two classes of Cage Compounds investigated within the NoE CMA, clathrates and skutterudites. |
Work Package 20A202:
Deposition of multi component thin films with composition gradient (PoP) |
WP Leader: Dr. Witold Gulbiñski, Koszalin University of Technology |
Abstract:
In the framework of this short term project, multisource magnetron sputtering has been used for the deposition of AlCuFe thin film coatings with composition gradient. Prior to deposition of multicomponent coatings, the deposition rate of single elements from individual sources has been measured and calibrated. Magnetron sources mounted in confocal geometry worked in DC power mode. The concentration gradient has been modified by changing of power dissipated at individual sources and/or distance source-substrate. The films have been deposited on 2-inch, (100) oriented silicon wafers placed in the confocal point of sputter guns. The deposition temperature has been varied between 90 and 300 deg C. Preliminary studies of composition show that concentration of components changes over substrate diameter in the range of 5 to 20 at.%, dependent on the element selected. The total concentration of impurities (mainly oxygen) was less than 2 at.%. The first results of micro-diffraction studies show that the phase composition of deposited coatings changes with composition gradient. It results in a change of local properties of the gradient coating as shown by local measurements (mapping) of contact angle. The presence of beta, lambda, omega as well as icosahedral AlCuFe phase has been confirmed. The obtained results support strongly the concept of the Combinatorial Synthesis and Screening project CSS. |
Work Package 20A203:
Coordinated characterization of Al-Cu-Fe PVD gradient coatings and their properties |
WP Leader: Dr. Patrik Schmutz, EMPA Duebendorf |
Abstract:
Al-Cu-Fe based complex alloys compounds show interesting properties like low friction coefficients in air and low wetting properties which make them promising candidates for coatings. A large effort is therefore planned within the frame of the CMA Network of excellence towards the development of such coatings. In order to speed up the process of finding optimal compounds, a structure and property screening approach on coatings with lateral composition gradients has been proposed. This project must be seen as a preliminary study to validate a coordinated and quick multi properties characterization within a network. The main aims are: i) to test the feasibility and limitations of a large multi-properties coating characterization; ii) to prepare micrometer thick ternary Al-Cu-Fe based coatings with significant lateral composition gradients; iii) to link different scientific partners and propose an optimised and quick sample and data handling procedure; iv) if possible to deposit a quaternary PVD layer gradient system with addition of Mo (for enhanced tribological and corrosion properties). With a 3 magnetron sputter sources PVD system, a 3 inch wafer was coated with targets resembling point sources (Al, Cu and Fe). The first observation is that a masking technique strategy for subsequent repositioning on the wafer and precise characterization would be desirable. Two directions are currently in formulation:
- Wafer structuring for very precise micrometer positioning and identification of area of interest.
- A rougher labeling allowing clear identification and attribution of larger 2x3 cm samples.
First results have been achieved. |
Work Package 20A204: CMA particles in alloys |
WP Leader: Sergio Scudino,
Leibniz-Institut für Festkörper und Werkstoffforschung IFW, Dresden |
Abstract:
Complex metallic alloys (CMA) display several interesting properties, such as good corrosion resistance and high-temperature strength, however, they are brittle at room temperature in the single-phase form, which limits their use in engineering applications. A way to improve the room temperature ductility is the development of a heterogeneous microstructure combining a soft metallic matrix with second-phase CMA particles. The CMA particles act as strength-bearing component, while the metallic matrix supplies ductility. Accordingly, in this project alloys containing high-strength CMA particles will be produced and the resulting microstructure and mechanical properties will be studied in detail. Through the close collaboration with industry, the aim of this project is the production of model alloys able to answer the questions from industry. |
Work Package 20A301:
Investigation of localized corrosion susceptibility and mechanisms of Al4(Cr,Fe) surfaces |
WP Leader: Dr. Patrik Schmutz, EMPA Duebendorf |
Abstract:
Al-Cr-Fe Complex Metallic Alloys (CMA) compounds show interesting surface properties like low friction, low wetting and good uniform corrosion resistance which make them candidates for new multifunctional metallic coatings. To maintain these properties might be difficult during surface degradation and in particular localized corrosion attack. This study is focussed at the formulation of mechanisms for localized corrosion. First investigations on Al4(Cr,Fe) CMA demonstrated very good thermodynamic stability of the surface oxides (passivation) in aqueous solutions ranging from very acidic to alkaline pH. Furthermore, an important advantage compared to stainless steel is the absence of active dissolution in the acidic domain which is a key factor for the propagation of localized corrosion. Concerning the localized corrosion susceptibility in Cl- containing solutions, measurements performed on single crystals of different orientations (100, 010, 001) did not show any localized attack down to an aggressive 0.01M HCl + 1M NaCl solution. However, for the polycrystalline samples, grains boundaries are preferential sites of localized attack. An aspect that will be further investigated, is the fact the passive surface oxide of Al4(Cr,Fe) in neutral solutions is a p-type semiconductor completely different from stainless steel (n-type) and Al (insulating). |
Work Package 20A302:
Low-Loss Complex Magnetocaloric Alloys |
WP Leader: Dr. Paul McGuiness, Jozef Stefan Institute, Ljubljana |
Abstract:
We have investigated samples of Gd5Ge2SiX-2FeX where X = 0, 0.125, 0.25 and 0.5, and Gd5Si2GeY-2FeY where Y = 0, 0.06, 0.25 and 0.5 using magnetic measurements and high-resolution transmission electron microscopy. We found that the Y = 0.25 sample, with Fe substituting for Ge, reduced the hysteresis losses practically to zero; however, we also observed this effect to be slightly, but significantly, less pronounced when we substituted Si with Fe. The TC of the matrix phase was found to increase when we added Fe for Ge, but decrease - and more rapidly - when we added Fe for Si. We also confirmed that the Gd5(Ge,Si,Fe)3-type phase, formed in increasing amounts when we add Fe, has a TC close to 100K. Our TEM results suggest that additions of Fe produce complex changes to the structure of the Gd5Ge2Si2 material, like amorphous regions, dislocations and planar faults, as well as crystallographically related grains. |
Work Package 20A303:
Magnetic properties of CMA formed upon devitrification of Fe-based BMG |
WP Leader: Dr. Mihai Stoica,
Leibniz-Institut für Festkörper und Werkstoffforschung IFW, Dresden |
Abstract:
The Fe66Nb4B30 alloy may form BMG, with good soft magnetic properties, properties which may even become better upon controlled devitrification. Upon heating, the glass transforms in a complex metastable intermetallic compound, a fcc-(Fe,Nb)23B6 structure with more than 110 atoms per unit cell. The project is currently running for the second milestone (MS2). Now we cast new BMG samples with a cylindrical shape (bars with 2-3 mm diameter and 50 mm length), disc plates 10 mm diameter and 1 mm thickness, and rings with 15 mm external diameter and 1mm x 1mm the cross section. For magnetic measurements (and for applications as well), the ring shape is the most suitable one because it supposes a closed magnetic circuit (as, for example, a transformer core). The small plates and the rods could be used as actuators- the moving part in a detector coil, for example. We study as-well the crystallization behavior and correlation structure-magnetic properties. |
Work Package 20A304:
Reactive diffusion for the synthesis of CMA coatings |
WP Leader: D. Mangelinck, CNRS Marseille |
Abstract:
The objectives of this project are to understand the mechanisms of the phase formation in Al-Cu-Fe thin films, to elaborate the icosahedral phase, i-AlCuFe (Al62.5Cu25Fe12.5) and to get thermodynamic and kinetic data on these systems. The work is organized in the following way: The samples are prepared by W. Gulbinski and coll. in Koszalin and by C. Vahlas and coll. in Toulouse. The technique of deposition is different for each team, namely, PVD and OMCVD respectively. The goal is to study the influence of the method of preparation on the phase formation. Then the samples are sent to D. Mangelinck and coll. for performing heat treatments and characterizations. First samples were already prepared by Gulbinski and coll. using PVD and by Valhas and coll. using MOCVD. Heat treatments and characterization are under investigations in Marseille. |
Work Package 20A401:
AlCrFe coated, graded deep-drawing steels and duplex steels
with enhanced corrosion resistance |
WP Leader: Prof. Aleksandra Czyrska-Filemonowicz
AGH University of Science and Technology Krakow
Project duration: 1st April- 30th November 2008 (8 months) |
Abstract:
The industry-oriented project is focused on the development of thin AlCrFe coatings of tailored micro/nanostructure on deep-drawing steels as well as duplex steels, which subsequently will produce a radical enhancement of the performance of the coated steels, especially improve their corrosion resistance.
These objectives will be achieved by application of multidisciplinary approach as advanced coating production technology and property tests as well as modern analytical methods for coating characterisation down to a nanoscale.
Thin AlCrFe graded coatings will be produced multisource magnetron sputtering followed by heat treatment. Characterisation of coatings micro/nanostructure will be performed by advanced electron microscopy and XRD methods. Quality of coatings and properties of graded steels will be tested by various methods (scratch tests, corrosion properties,..). The relationship between nano/ microstructure and properties of graded deep- drawing steels as well of duplex steels will be determined.
Main deliverables: - to produce demonstrator pieces: coated deep-drawing steels and coated duplex steels with improved electrochemical – and pitting corrosion resistance. |
Work Package 20A402:
CMA as combined structural material and catalyst for methane activation: REACAT |
WP Leader: Prof. Robert Schlögl, Fritz-Haber-Institut Berlin |
Abstract:
The unique electronic structure of CMA offers the possibility to use metals in high temperature catalysis under conditions where conventional alloys segregate and corrode. The low price of the constituents allow using CMA in addition as structural materials to build a metallic reactor with catalytically active walls replacing traditionally used supported noble metal systems such as platinum. This offers novel engineering options for controlling selectivity and product distribution. The price of such a device is not prohibitive for scaling into technical dimensions. |
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