Community Research and Development Information Service - CORDIS

FP7

SAMBA Report Summary

Project reference: 309849
Funded under: FP7-NMP

Periodic Report Summary 2 - SAMBA (Self-Healing Thermal Barrier Coatings)

Project Context and Objectives:
The SAMBA project deals with the creation of a new, unique self-healing thermal barrier coating (TBC) for turbines and other thermally loaded structures in order to realize a significant extension of the lifetime of critical high-temperature components. The concept is based on novel Al2O3 coated Mo-Si particles embedded in the TBC layer, typically consisting of yttria-stabilized zirconia (YSZ. As the current TBCs do not exhibit any self-repair, the new self-healing TBC will offer a reduction of the number of TBC replacements during an engine lifetime and enhance the reliability of the critical components.

Thermal barrier coatings are applied to metallic surfaces of combustion chambers, blades and vanes in gas turbine engines used for propulsion and power generation to allow for higher operation temperatures. This thermal barrier is crucial to enhance the engine’s fuel efficiency and consequently to reduce the emission of greenhouse gasses. The turbines and the TBCs experience severe thermal cycles spanning a range of over 1000 °C due to starts and stops of an engine or installation. During cooling from the operation temperature to room temperature, high stresses develop due to a mismatch between the coefficients of thermal expansion of the metal substrate and the ceramic TBC. In time, these stresses result in the development of crack patterns in the TBC that coalesce and ultimately lead to failure. Cracks that run through the TBC perpendicular to its surface are not detrimental per se, but in conjunction with cracks that develop parallel to the interface they lead to spallation (i.e. fragmentation) of the TBC, directly exposing the substrate to the high-temperature environment.

The primary goal of this project is to realize and optimize the self-healing capacity of thermal barrier coatings via Mo-Si based dispersed particles for application in aero engines and industrial gas turbine engines which prolong the lifetime of their critical components. This will be achieved through a combined theoretical, experimental and modelling approach of a new, innovative self-healing concept that relies on the encapsulation of the healing particles.

Project Results:
The project started in March 2013 with a kick-off meeting in Delft (The Netherlands), where the details of each work package were presented and discussed. The timeline including the objectives, deliverables and milestones of the project were reviewed.
WP1 Financial and administrative management
The work covered in this package entails all the subtasks needed to facilitate the efficient development of the project activities. This ranges from providing the necessary financial and administrative management to ensuring exchange of information among the partners.
Amendment 2 has been processed dealing with the departure of PEPM and re-distribution of remaining tasks and budget to TU Delft. It also concerned the mitigated planning of deliverables.
WP2 Concept and Design
The research foreseen in this work package is aimed to deliver vital quantitative data for the design and subsequent manufacturing (WP3) of the prospective self-healing TBC, which will be achieved through combined experimental-modelling studies.
During the period of M19-36 the activities were mainly focused on experiments and modelling of the oxidation kinetics of the MoSi2-based, B and Al-containing powders. The major variable experimental parameter has been the Al-content of the particles (2, 6 and 12 wt.% respectively). The experiments were performed at 1100 °C.
In situ encapsulation of healing particles in a YSZ matrix by selective oxidation Al was demonstrated. Annealing of YSZ with MoSi2 with 2wt%B and 6 wt%Al in pure Argon at 1100 °C already led to the formation of an alumina shell. The encapsulation remained stable after high temperature exposure in air although some SiO2 was formed between the alumina shell and the core of the healing particle.
A generic model is developed to predict the crack gap filling kinetics by oxidation of healing particles in a matrix (usually a ceramic). The parameters that describe the crack gap filling of MoSi2 particles without and with B (as envisioned in self healing TBC) were determined from oxidation experiments using differential thermal and thermogravimetric analysis (DTA/TGA).
The numerical simulations were focused on:
• Numerical simulation of experiments of the benchmark TBC in order to calibrate and verify the constitutive models. Results from WP4 and WP5 will be used for this purpose.
• Numerical implementation of an oxidation growth model for the TGO. This model will be coupled to the thermo-mechanical simulations to simulate the process that nucleates and propagates microcraks in the TGO and TC layers.
• Numerical simulation of cracks in a TBC system that includes healing particles in the TC layer. This task will include systematic parametric analyses of different configurations for the healing particles (size, distribution and properties).
The first and third objectives mentioned above have been accomplished during the reporting period. The second objective has been modified since it was identified that a self-healing model was more critical than a TGO growth model. The self-healing model was developed and implemented during the reporting period. The equations for the TGO growth model have been identified and the model will be implemented in the coming period together with the lifetime simulations.
The oxidation studies and also experiences with the manufacturing of a self-healing TBC (WP3) as well as results on characterization (WP5) lead to deliverables D2.1 and D2.2, a first and an improved specification of the Mo(SiAl)2+B healing particles, respectively. Further the studies on the oxidation kinetic of the healing particles and their characterization (WP5) were used in a first quantitative description of the crack gap filling kinetics resulting in deliverable D2.3.
WP3 Manufacturing
Development of the technology and the production of self-healing TBC by atmospheric plasma spraying (APS) as well as the corresponding self-healing ceramic material by spark plasma sintering (SPS).
For the design studies various samples were prepared by spark plasma sintering (SPS); see D3.4 and D8.1. It comprises yttria stabilized zirconia (YSZ) and Mo-Si alloys for testing mechanical and thermal properties and oxidation behaviour. Also composites of YSZ with Mo-Si particles were prepared to investigate crack healing behaviour. Yet samples are still being prepared for these studies. Moreover, complete self-healing TBC systems have been prepared by SPS as an alternative for APS. To this end, MoSi2+B healing particles pre-encapsulated by precipitation and sol-gel method (cf. WP2) were used.
A new injector holder was developed to spray layers with YSZ and MoSi2, such that the powders can be injected at different places of the plasma flame; see D3.3 and D8.1. Hence, the MoSi2 powder can be deposited with colder spraying conditions than the YSZ to produce a coating, which contains a sufficient amount of Si for the self-healing effect. Using coarser MoSi2 based particles it was possible to produce coatings with even lower Si evaporation showing the desired MoSi2 based particles in the YSZ matrix.
To improve the manufacturing of a self-healing TBC, series of samples using a wind sifted powder with 2 wt% B and 6 wt% Al were produced (cf. WP2). Heat treatment of the samples for 23 h at 1100 °C with a rapid cooling has led to the spallation of the coatings during cooling. An experimental series was investigated to cool the samples slowly in order to release stresses and be able to get encapsulated self-healing particles. These samples showed no delamination and the analysis has shown that an oxide layer was produced around the MoSi2 particles.
To optimize the spraying parameters for a self-healing TBC, a design of experiment (DOE) was performed; see D3.5. The parameters for this DOE were determined by preliminary tests, which were also performed to ensure that all parameter sets investigated in the DOE would produce a sound coating.
A first set of self-healing TBCs manufactured with wind sifted MoSi2 powder containing 2 wt% B and 6 wt% Al. The coatings showed cracking after the heat treatment and after 1-4 thermal cycles the cracking increased. Nevertheless, these samples showed the formation of an oxide scale around the healing particles. The cracking may be due to be induced by the oxidation of healing particles that were not sufficiently encapsulated.
To improve the ability of encapsulation a wind sifted MoSi2+B powder with 12 wt% Al was used to produce an improved self-healing TBC; see D3.6. The produced coating again showed early crack development during the thermal cycling. SEM analyses of the as sprayed coating showed a high loss of Si and Al during the spraying process, which may be solved by optimizing the spraying parameters for this new powder.
The following deliverables were finalized in he reporting period: D3.5 First design self-healing TBC samples, and D3.6 Improved design self-healing TBC samples. However, the performance of these self-healing TBC is not yet at the desired level and further improvements are in progress.
WP4 Lifetime and Failure Analysis
The focus of this WP is on the assessment of the damage evolution in TBCs upon thermal cycling and on the extension of lifetime by self-healing. The experiments will be carried out with a standardised furnace thermal-cycle test on both the benchmark and self-healing TBCs.
Additional short and long term thermal cycle tests at 1100 °C of the benchmark TBC have been done to study the damage evolution and to improve the EoL statistics. To study the effect of temperature, also at short-term thermal cycle tests at 1050 °C of the benchmark TBC have been executed.
The first series of self-healing TBC with MoSi2 + 2 wt%B healing particles alloyed with 6 and 12 wt%Al have been thermal cycle tested and analysed.
As an additional activity, TBC systems prepared by SPS have been thermal cycle tested and analysed. Thermal cycle tests of a self-healing TBC system with pre-encapsulated MoSi2 + 2 wt%B + 6 wt%Al healing particles prepared by SPS is in progress.
WP5 Characterization
To establish crack propagation and crack healing mechanisms by characterising both bulk TBC materials and TBCs on substrates. The results from this work package will be used to identify the composition and microstructure of TBCs having a self-healing function and promote TBC lifetime.
A model was devised to describe the kinetics of the crack healing reactions in YSZ with MoSi2 type of particles; see D8.1. Now, the kinetic parameters as a function of temperature have been determined from thermogravimetric and bilayer diffusion and oxidation experiments. In this context the effect of boron addition to the healing particles have been studied.
The damage and self-healing process in TBCs upon thermal cycling was investigated using SEM and X-ray microanalysis. A detailed study was carried out on the first manufactured self-healing TBC samples (cf. WP3) in order to obtain a better understanding of the early crack damage in these TBCs and the effect of the MoSi2 type of healing particles.
Continuing the non-destructive 3D X-ray tomography to determine the evolution of crack damage during thermal cycling (cf. D8.1), a detailed investigation was done to quantify crack propagation at different length scales.
Thermographic inspection of benchmark TBC samples at different stages of thermal cycling (cf WP4) to determine non-destructively the extent and nature of crack damage was completed. The thermographic analysis method has been further optimized to deliver reliable quantitative data on the crack damage progression.
A full metallographic analysis of thermally cycled benchmark TBC using optical and scanning electron microscopy was carried out (according to D4.1) to determine crack formation and the dominant failure mechanisms. The samples were characterized in terms of layer thicknesses (TBC, TGO and BC), porosity, phase composition etc.
The Young’s modulus and hardness of YSZ and YSZ with MoSi2 type healing particles was first determined for bulk specimens prepared by SPS; see D81. The same methods to determine these mechanical properties were applied to TBC coatings to determine the effect of the healing particles and thermal ageing.
The Young’s modulus and hardness of the top coat and bond coat have been evaluated using micro indentation and the Oliver-Pharr method. A trend in hardness and Young’s modulus values can be observed in one batch of samples such that both HIT and EIT decrease upon thermal exposure in the self-healing part of the coating. However, values are increasing in the benchmark YSZ part of the coating. This trend is not noticeable in the other batch, as both hardness and Young’s modulus values appear constant. However, due to the lack of the benchmark YSZ part of the top coating in as-received sample the results are not conclusive.
In addition fracture toughness values evaluated from indentations of the cross section of the benchmark system at various stages of thermal loading show a gradual decrease upon exposure. However, the large variability in material properties throughout the microstructure makes it difficult to draw absolutely conclusive results regarding this particular material property.
The effect of incorporating MoSi2 type of healing particles into YSZ on its thermal conductivity has been studied and a relation between the volume fraction healing particles and the thermal conductivity has been established.
The following deliverables were completed: D5.1 Optimization of healing particle size, composition and bulk samples and TBCs with self-healing, D5.2 Quantification of crack damage and crack healing using X-ray tomography and thermography, and D5.3 Establish relation between fracture toughness and damage tolerance due to thermal cycles.
WP6 Rig Demonstration
In this WP the performance of the developed self-healing thermal barrier coating will be demonstrated by application of this coating to a component that will be tested in a real engine.
Due at the end of the project.
WP7 Dissemination
This work package aims to collect the knowledge and the results of all technical work packages and to facilitate appropriate exploitation of these results and to disseminate non-confidential knowledge to the industry at large. In addition, this work package aims to create awareness for this project on self-healing ceramic material in the academic and industrial community and provide a two-way communication channel between the project and the outside world.
A flyer outlining the SAMBA project and a ‘teaser’ have been prepared and distributed.
Presentations, conference contributions and publications related to the SAMBA project are done. The output on dissemination of the project concepts and results is listed in Chapter 4.
The deliverable D7.2 Protocols for standardization has been reported.
WP8 Technical Coordination
The objective of this WP is to coordinate, to monitor and to supervise the project’s scientific progress as a whole, and to coordinate the interactions between the work packages.
In the second stage of the project (M19-M36), 3 regular progress meetings were organized. All partners attended these meeting to discuss project results and plan activities. Also many bilateral meetings with various partners were held to initiate and discuss activities. Further, emails, skype and telecons were used to coordinate the research.
In the first stage of the project milestones MS1 and 2 were met. In the second stage of the project milestones MS1 (First self healing TBC) and MS2 (improved design self-healing TBC) were achieved. To reach the project goal (improvement of TBC life by self healing) still requires significant optimization. With the positive review meeting following the achieved results as reported in M36, also MS3 (First self-healing TBC manufactured, tested and
Characterized) and MS4 (Improved Design of
self-healing TBC) have been reached.

Potential Impact:
Ceramic thermal barrier coatings (TBCs) themselves already contribute tremendously to sustainable technology, because it enhances the engine efficiency by allowing higher operation temperatures, which saves fuel and thus reduces CO2 emissions. Furthermore, it protects the high-tech structural components (made of single crystal superalloys) against severe high-temperature corrosion, thereby contributing to durable use of resources. The materials and their amounts used to produce the current as well as the prospective self-healing TBCs are abundant, relatively cheap and not environmentally hazardous. The added value grows exponentially when starting from the raw materials to application by plasma spraying onto components integrating these into complete parts for gas turbine engines, which finally are applied in complete systems such as aeroplanes or power stations.
The innovative concept of healing crack damage proposed here is generic and can be adopted naturally to develop a wide range of new self-healing ceramics. Clearly, this will offer substantial opportunities to prolong the lifetime and enhance the reliability of other ceramic components used in high-temperature applications. Further ahead there will be affordable ceramics with self-adapting, self-healing and multifunctional features to generate novel applications for saving energy, reducing carbon footprints across the entire value creation process of the energy, transportation and manufacturing industries. Advanced structural ceramics have played and will continue to play a critical role in all aspects of energy production, storage, distribution, conservation, and efficiency. These ceramics may ultimately outperform other materials (e.g. scarce metals) due to reliability, high durability, high-temperature capability and other unique properties. Such developments will then greatly benefit from the knowledge and experience gained in this project.
In 2009 a roadmap for advanced ceramics 2010- 2025 was developed under the auspicies of the German Ceramic Society (DKG) and the German Materials Society (DGM) that addresses these future novel ceramics also with self-healing ability to provide guidelines for future investments for policy makers, scientific organizations and industrial developer. In the sequel, facts of this roadmap will be cited in so far as they are related to the work proposed in the SAMBA project.
The SAMBA project aims to deliver a proven concept, which is preliminary tested. For further application, more development and testing is required than covered by the length of this study. This will be taken up by the interested partners in either a follow-up project and/or initiated by commercially interested consortium partners.
The foreground results and IP of this project will be protected by patents when appropriate. Otherwise, results will be published.

Expected Impact
Ceramic thermal barrier coatings (TBCs) are applied on the most critical parts of engines exposed to a high-temperature environment, allowing operation beyond the melting point of the structural components and, simultaneously, extending the lifetime of these components. TBCs were initially used in aero-engine parts, but new fields of application are appearing in other fields where it is necessary to improve thermal management and enhance fuel efficiency. The new innovative self-healing TBC will significantly prolong the lifetime of critical components, as the current TBCs do not exhibit any self-repair. The SAMBA project aims to extend the lifetime of TBCs with at least 20-25 %. This self-healing TBC will lead to a reduction of the number of replacements during a gas turbine engine lifetime and offer prime reliant functionality of the coated parts. Moreover, implementation of a self-healing mechanism in the ceramic TBC by itself will reduce the probability of early failure, hence enhancing the reliability of the critical components.
The engines concerned are used primarily for propulsion of aircrafts, ships, submarines, and for generation of electrical power. Their operation relies on the reliability of critical components, which are covered with a TBC. Failure of the TBC results in accelerated degradation of the critical component (e.g. blades or vanes) and ultimately in shut down of the engine. Although, in practice also modern monitoring techniques and engine operation management are focussed on preventing such failures to occur, the new prospective self-healing TBC also promotes the safety of aircrafts, ships, submarines as well as of electrical power plants for electricity. It is foreseen that the market of small turbine engines for automotive application will boom and can benefit from the developments of the research proposed here.

Expected impacts on societal and economic benefits
The electric power generation in Europe, but also worldwide, relies to a great extent (30 to 40 %) on gas turbine engines (with TBCs). These engines are also indispensable for accommodating fluctuations in demand of electric power and to deal with peak loads. This aspect becomes even more important with the ambition to increase use of renewable solar and wind energy for electric power generation, since renewable energy supply inherently fluctuates. Self-healing TBCs may be a solution to accommodate the associated increase of thermo- mechanical loads.
It is evident that the effects of electric power failure on society and economics can be devastating. A reliable and secure supply of electric power is therefore vital to fulfil the needs of an active society and economy. Moreover, a reliable and secure operation of gas turbine and diesel engines, used as back-up system for electric power generation in case of a power failure, is crucial for critical infrastructures, like e.g. hospitals, certain industrial plants, cold storages etc. Thus, the new self-healing TBC with prolonged lifetime and enhanced reliability will directly contributes to enhance safety in a wide range of situations.
A similar reasoning applies to safety of turbine engines for aeroplanes. Example exists that any damage or failure in the turbine engine for propulsion can lead to a crash endangering human lives in the air as well at the ground.
There is worldwide an increasing demand for higher efficiency for the generation of propulsion and electricity in order to reduce the use of fossil fuels, hence saving the environment by reducing the carbon footprint. This can be accomplished by higher operation temperatures, which requires improved thermal barrier coatings with reduced thermal conductivity and enhanced high-temperature stability as well as burner nozzles and heat exchangers. Self-healing ceramics may be a solution for the expected high thermo- mechanical loading scenarios.

Economic impacts
The lifetime of TBC systems now lies between 2000 and 4000 thermal cycles. For an aero- engine, this means that the TBC systems on average need to be replaced about four times during the lifetime of an aircraft, and these are cost-intensive maintenance operations. A similar situation applies to gas turbine engines used for electric power generation. Moreover, with increasing use of renewable energy (solar and wind) the number of starts and stops of gas turbine engines also increases in order to match the fluctuations in supply and demand of electric power.
The economic benefits of a self-healing TBC with prolonged lifetime can be explained by considering the maintenance cycle of the turbine engines. Currently, the global market for thermal barrier coatings is over 3000 million € according to the market overview of one of our industrial partners Flame Spray Technology, which comprises the use of 2 million kg zirconia. Considering that during the lifetime of an gas turbine engine on average the TBC coating must be replaced 4 to 5 times, then about 75 % of the market is related to repair. Hence, if one replacement can be saved by applying self-healing TBCs, i.e. an improvement of the lifetime with about 20-25% should be realized, then the direct economical impact should be about € 600 to 800 million €. This amount will be even higher if also the cost savings associated with the down time of the engines is included.
As can be expected, the TBC market for both manufacturing and supply is currently present in the advanced industrialized countries. Europa holds a large share of this market. The main competitor is the USA. The Asian and Australian TBC market is relatively small and is for the time being dominated by Japan. The TBC market in Europe is evenly distributed.
The market for TBCs will increase not only due to the expansion of the fields of applications, but also due to the global increase of energy consumption. The World Energy Council (WEC) has predicted that at least by 2050 the world will need to double today’s level of energy supply. This includes both transport and electricity. As the type of fuels (including bio-fuels) to realize this increase in energy supply will not change dramatically, the market trend for both industrial and aero gas turbine engines will increase accordingly and so will the overall impact of a self-repairing TBC system.
It has been forecasted by the European aero engine industry it has been forecasted that over the next 20 years 137,000 engines (worth over 800 billion US$) will be required to power more than 63,000 commercial aircraft and business jets. This comprises nearly 3 times as many deliveries than in the last 20 years. Asia became the largest market for mainline aircrafts and freighters in 2010, and will be double the size of the European or North America by 2031. The European aero engine industry is involved in the SAMBA project through Volvo Aero Company (with an annual turnover of 730 million €).
By the European aero engine industry it has been forecasted that over the next 20 years 137,000 engines (worth over 800 billion US$) will be required to power more than 63,000 commercial aircraft and business jets. This comprises nearly 3 times as many deliveries than in the last 20 years. Asia became the largest market for mainline aircrafts and freighters in 2010, and will be double the size of the European or North America by 2031.
A similar forecast has been made by the aero industry of the USA. Boeing anticipates delivery of 33 500 new airplanes over the next 20 years (valued 4.0 trillion US$). The Far East, Latin America and China have been identified as new key markets. By 2030 China’s airlines alone will need 5,000 new airplanes (valued at $600 billion US$), Southeast Asia 2750 airplane (410 billion US$), and Latin America requires 2570 airplanes (250 billion US$), which are considerable demands compared to the U.S.A that requires 7530 new airplanes (760 billion US$) over the next 20 years. Finally, the European manufacturers also have a large internal market to service with European airlines forecasted to acquire a total of 7550 new airplanes valued at 880 billion US$880).
The European aero engine industry is involved in the SAMBA project through Volvo Aero Company (with an annual turnover of 730 million €).
A similar market perspective exists for gas turbine engines for electric power generation. The European industry is also here a key supplier of gas turbine engines for electric power generation on the world market, and Asia will be the largest growth market. 687 gas turbine engine units were ordered in 2011 worldwide. Considering that by 2050 the demand for energy will be doubled, the size of the world market for gas turbine engines will be twice as large as today.
The European industrial gas turbine engine industry delivers today combined cycle power plants with efficiency greater than 60%. This is not only the highest of any power plant it is nearly double the average efficiency of the globally installed fossil power generation. It is therefore economically beneficial to replace old power plants and thus enhances the market for industrial gas turbine engines. The European industrial gas turbine engine is involved in the SAMBA project through Alstom (with an annual turnover of 20.9 billion € of which 50% is related to Alstom Power).
The global market for advanced technical ceramics is about 30 billion € (40 billion US$) encompassing to electronic components, chemical, medical and environmental products, electrical equipment, industrial machinery and transportation equipment. Continuous long-term growth with reasonable annual rates is expected especially after the recovery from the recent financial and economic crisis.
The markets for engineering ceramics (covering mechanical, medical, environmental and thermal applications) were valued at approximately 2.6 billion € in Europe and 1.4 billion € in the USA in 2010. Consumption of engineering ceramics is expected to reach over 3.1 billion € in Europe and over 2.6 billion € in the USA by the year 2016, corresponding to average annual growth rates of 3.1 % and 2.7 % respectively. It can be anticipated that the Asian market for engineering ceramics will grow much faster. There is a large and growing market for engineering ceramics and hence a great opportunity for the new functionality of self-healing of such ceramics.

Expected impacts on improved competitiveness of the European industry
If a TBC system with sufficient self-healing capacity can be realized, then the economical benefits will be more than significant (see Section 3.1.2.2). First, the manufacturer of such a coating system can offer a unique product and thereby acquire a stronger position in the world market. Secondly, the users of a TBC system with self-healing capacity (e.g. airline companies and producers of electricity) will benefit from the longer lifetime of the coating system itself and hence the critical components of the gas turbine, which brings about less engine revisions and thus a reduced engine down time. Thus, realisation of the new functionality of self-healing TBC will significantly improve the competitiveness of the European industries in the whole supply chain, from coating producers, engine manufacturers to end-users, compared to their counterpart industries in the USA and similar upcoming industries in Asia and Brazil.
It has been forecasted that the market for both industrial and aero turbine will grow tremendously in the coming decennia for a large part in Asia (doubled in about 20 years time). Since European original equipment manufacturers (OEMs) of gas turbine engines for power generation and propulsion are key suppliers on the world market, they will profit from this market development when maintaining and improving their competitiveness through lead in knowledge and innovation. The SAMBA project, aimed at developing affordable self-healing TBCs, offers such innovation.
Since European original equipment manufacturers (OEMs) of gas turbine engines for power generation and propulsion are key suppliers on the world market, they will profit from this market development when maintaining and improving their competitiveness through lead in knowledge and innovation so that beside the EU they can supply regions such as the USA, China and the Far East as well Latin America. The SAMBA project, aimed at developing affordable self-healing TBCs, offers such innovation, which allows for more reliable, more fuel efficient turbine engines that also require less maintenance and repair and are thus more economical. It also allows European companies to reap the value addition across the value chain in sectors such a ceramics production, energy production and propulsion. The involvement of companies such as Flame Spray Technology Volvo Aero and Alstom will ensure that the industry can reap these benefits across the production chain and thus the value add as it will channel development in the project to accelerate the path to uptake by industries and strengthening of their competitive advantage.

List of Websites:
http://www.sambaproject.eu/

Contact

de Wolde, Karin (Financial officer)
Tel.: +311527 84505
E-mail
Record Number: 187498 / Last updated on: 2016-08-22