Community Research and Development Information Service - CORDIS

FP7

THEBARCODE Report Summary

Project ID: 310750
Funded under: FP7-NMP
Country: Greece

Final Report Summary - THEBARCODE (Development of multifunctional Thermal Barrier Coatings and modelling tools for high temperature power generation with improved efficiency)

Executive Summary:
THEBARCODE Project has been funded under Call: FP7-NMP-2012-SMALL-6, Sub-Scheme: CP-SICA. The consortium composed by 3 SMEs, 3 large companies, 4 RTD institutions and 2 Universities. These partners come from 5 EU member states (Belgium, Germany, Greece, Romania, UK) and 3 Eastern European countries i.e. Armenia (1 partner), Russia (2 partners) and Belarus (1 partner).
The project focused to contribute in the efficiency of power generation in gas turbine processes by the development of advanced parts or components of significantly improved performance as well as software providing optimized process parameters. The aim of this project was the development of materials, methods and models suitable to fabricate, monitor, evaluate and predict the performance and overall energy efficiency of novel thermal barrier coatings for energy generative systems. By the radical improvement of the performance of materials “in service”, by the application of novel thermal barrier coatings, structural design and computational fluid simulations a significant improvement in energy efficiency and cost effectiveness was achieved.
The project addressed the following scientific and technological issues:
• New TBC formulations with long-term stability, more resistant under extremely severe operating conditions (e.g. creep, fatigue, thermal-mechanical fatigue, oxidation and their interactions, at high service temperatures) thus the maximum application temperature will be higher and so performance during energy generation.
• Flexible and cost effective production systems based mainly on thermal spray (SPS/SPPS, APS, HVOF) but also EB-PVD in order to realize patterned functional TBCs with improved properties.
• Application of structural analysis and fluid simulation software, including radiation, combustion, heat transfer, fluid-structure interactions and conjugate heat transfer models for the development of detailed models for the operational performance and prediction of spallation phenomena and failure.
• Environmentally friendly process using chemical formulations free of hazardous and toxic solvents.
Scale up production of materials developed within TheBarCode consortium as well as commercial ones has been successfully performed. YSZ and Hexaluminate oxide suspension in quantities of 10L each have been produced for the needs of Suspension Plasma Spray deposition technique with the aim to develop multilayered TBC systems. These TBCs were deposited on real turbine parts (blades) produced and distributed by the end user. The experimental work of WP3 consisted on the deposition parameters and microstructural tuning of innovative TBC's together with the testing results concerning their thermal shock and cycling behaviour revealed the use of lanthanum aluminate and hexaluminate oxide as the most promising materials to be applied on the real parts. Quality control of the scaled up materials including physicochemical and rheological properties resulted in a material data sheet accompanying each oxide.
The liquid route SPS and SPPS thermal spray techniques respectively were used by MIRTEC for the development of multi-layered TBC systems on 7 blades. For comparison reasons 7 more blades were coated by MIRTEC using the dry route Atmospheric Plasma Spray deposition technique. Thus, successful scale up of TBC systems deposition from lab scale sized specimens to pilot scale real parts delivered by SATURN was performed. Innovative multilayered TBC systems were developed using materials synthesized within the consortium. Innovative SPS and SPPS thermal spray deposition techniques were used by MIRTEC for the layers’ development. The project foreground is exploited directly by participants by incorporating the new materials and technologies in their products and services.

Project Context and Objectives:
The European Council in 2007 adopted ambitious energy and climate change objectives for 2020 – to reduce greenhouse gas emissions by 20%, rising to 30% if the conditions are right, to increase the share of renewable energy to 20%, and to make a 20% improvement in energy efficiency. Achieving an energy efficient Europe is the 1st out of the 5 priorities of the new energy strategy. However energy demands in EU are rising (2%/year) and there are no indications that this demand will be curbed significantly in the short or medium term despite the measures adopted. At the same time the electricity generation capacity that holds more than 20 % of production is aging and a large number of power plants are scheduled for retirement. Capacity planning for new power generation facilities has its basis in economic criteria and energy policy goals of the EU. Concerning the future fuel mix energy outlookers tend to agree that the contribution of renewable energy sources will not dominate before 2030 while the nuclear power plant capacity will shrink or remain the same. Therefore fossil fuel power plants will remain the backbone of the EU energy generating sector until at list 2030. In 2020 around 40 % of electricity will still be produced by conventional power plants. Under these circumstances minimal carbon footprint advanced power plants have to be deployed e.g CO2 capturing but much more expensive units are not expected to be widely operational before 2020. These statements highlight the fact that there will be an optimal technology mix that could simultaneously satisfy all objectives of the EU energy strategy. Therefore the high temperature turbine engine units working under the Brayton cycle will remain the prime mover of power generation. Thus any significant technological improvement towards better performance and energy efficiency in this field of turbines will have a direct positive impact in the short term on the EU energy strategy.
Thus, an intensive challenge for industrial and aircraft gas turbine engines in the recent decades is to increase operating temperature to a maximum without overheating the metallic parts during engine service. Research to reduce the consumption of fuel and the emission of pollutants by turbine engines is of high interest as turbine engines are employed in aerospace propulsion, power generation and marine propulsion. Under the energy efficiency scope, technologies leading to advanced power plants, involve a transition to very high hydrogen fuels derived from syngas and syngas burned in nearly pure oxygen using steam to control temperatures (oxy-fuel systems). The transition will require materials technologies to accommodate expansion gases that are hotter and contain high concentrations of water vapor and generally are more aggressive gases to materials ‘in service’. Today, the lifetime of materials used in turbines needs to be increased by augmenting their resistance to corrosion phenomena at high temperature and such improvements also decrease the cost of turbines. The “hot parts” of co-generative systems, are subject to a series of tribological stresses due to erosion at speeds of over Mach 3, abrasive wear, thermal shock, etc. One of the solutions consists in covering the combustion chamber and the blades with a thermal barrier coating. They protect and insulate the metallic gas turbine engine components from the hot gas stream allowing higher combustion temperatures and improving engine efficiency. Another approach to the aforementioned scientific and technological disciplines is optimization by design, modeling and computational fluid simulation. Such an approach may be converging or guiding to materials science and engineering. Thus, modeling may cover turbulent flow, combustion chamber flow, heat and mass transfer, failure methodologies and life predictions. Component design can lead to better efficiency, lower operation and maintenance costs and improved service life. Therefore, all fields mentioned are highly synergistic towards engines improvement and energy generation efficiency.
This project is focused to considerably advance the efficiency of power generation in gas turbine processes by the development of advanced parts or components of significantly improved performance as well as software products providing optimized process parameters. The aim of this project was the development of materials, methods and models suitable to fabricate, monitor, evaluate and predict the performance and overall energy efficiency of novel thermal barrier coatings (TBCs). By the radical improvement of the performance of materials “in service”, by the application of novel TBCs, structural design and computational fluid simulations a significant improvement in energy efficiency and cost effectiveness will be achieved.
The main objective of the proposed project was to develop radically improved TBCs (working beyond SoA limits), to understand the interrelations between the spallation factors so that targeted modifications in the structure and morphology of the TBCs can be made. This was accomplished as an ancillary activity by the use of modelling in combination with experimental observations. In this way prediction tools will be developed by combination of short term experimental observations and a prediction of the functional performance of the novel TBCs can be achieved.
The project addressed the following scientific and technological issues, which shall offer significant impact concerning successful implementation of energy efficient high temperature generation units. New TBC formulations with long-term stability, more resistant under extremely severe operating conditions thus the maximum application temperature will be longer, leading to higher performance during energy generation. Flexible and cost effective production systems based on thermal spray in order to realize patterned functional TBCs with improved properties. Application of structural analysis, fracture mechanics and Computational Fluid Dynamics (CFD) including heat transfer, fluid-structure interactions and conjugate heat transfer models for the development of detailed models for the operational performance and prediction of spallation and failure. Environmentally friendly process using chemical formulations free of hazardous and toxic solvents. Standardized thermo-mechanical, tribological and coating adhesion testing including thermal shock testing in extreme conditions.
Accordingly the path of the implementation of the project can be outlined in four interrelated phases:
A. Materials synthesis and testing: i) development of top coat materials and wet or dry formulations suitable for topcoats deposition, ii) development of bond coat materials (including functional diffusion barriers)
B. Coatings development, fabrication and testing: i) Application and optimization of dry deposition methodology for the new materials, ii) Application and optimization of wet deposition methodology for the new formulations, iii) Development of smart coatings of tunable nano and microstructure (graded)
A. Development of models and prediction tools: i) Numerical modelling of the TBCs performance focused on experimental and theoretical parameters, ii) Computational Fluid Dynamics based optimization and energy efficiency assessment, iii) Service lifetime prediction tools (based on CFD and fracture and wear modelling)
B. Assessment of Technology: Assessment of product (materials and coatings), process (deposition technology) efficiency, sustainability and cost & performance effectiveness upon application, for the entire life-time of the project; feedback (where necessary) to facilitate the decision making process.
The main objectives had been to prepare: new materials suitable for TBCs; powders with the metal clad coatings to attain better coating adhesion; improved hierarchical/graded coatings by plasma spraying methods; to correlate the physicochemical properties of materials and the structural features of their coatings to the overall performance of TBCs; to investigate spallation prediction tools; to develop a macroscopic numerical model about failure mechanisms. Also to deliver a cost benefit analysis of TBC parts and software tools, benchmarking and assessment of the technology in terms of environmental impacts, energy efficiency, and potential integration into existing power plants.

Project Results:
THEBARCODE Project has been funded under Call: FP7-NMP-2012-SMALL-6, Sub-Scheme: CP-SICA. The consortium is composed of 3 SMEs, 3 large companies, 4 RTD institutions and 2 Universities. The main objective of the project is to develop materials and processes (“hardware”) to establish a route of preparing more efficiently high temperature power for turbine components.
The project finished on schedule in selecting the optional materials. Deliverables were delivered on time with minor delays that do not affect implementation and the milestones are succeeded. The consortium includes Eastern European country partners from Armenia, Russia and Belarus and this indulges a difficulty in management as partners from these countries are not so experienced.
In order to ensure a smooth execution of the project, the project partners agreed to grant royalty-free access to Background and Foreground IP for the execution of the project.
The project advanced the efficiency of power generation in gas turbine processes by the development of advanced parts or components of significantly improved providing optimized process parameters.
The foreground that has potential for exploitation is presented briefly below:

Key Exploitable Result 1 Optimized bondcoat materials and their preparation protocols
Modify bond coat compositions towards better compatibility of TBC constituents as well as the compositional control to maintain the bond coat ductility and thermal expansion. The feasible approach of the bond coat modification supposes creation of graded bond coat structure via the deposition of an additional metal/ceramic layer with the intermediate combination of physical properties between the bond coat and top coat. For this, special composite metal/ceramic powders with controllable composition and particle morphology are required. The purpose of the protocol is to ensure a reproducible manufacturing process of such powders.
This Preparation protocol determines the list of starting materials, equipment and the order of operations to prepare nickel-zirconia and cobalt-zirconia composite clad powders for thermal spray applications by electroless plating. The composite powders consist of ceramic core (spherical thermal spray zirconia powder) encapsulated into continuous metallic coat. Resultant powder compositions according this Protocol are given below (wt.%):
1. Y-stabilized zirconia powder Metco 204NS + Ni;
2. (Y, Ce)-stabilized zirconia powder Metco 205NS + Ni;
3. Y-stabilized zirconia powder Metco 204NS + Co;
4. (Y, Ce)-stabilized zirconia powder Metco 205NS + Co.

Innovativeness introduced compared to already existing Products/Services
• The composite clad powders ensure homogeneous microstructure of intermediate “damping” layers in graded TBCs;
• Flexible controlling the contents of ceramic and metallic components in the powder is possible;
• Process parameters and compositions of not expensive electrolytes for cladding highly-dispersed substrates at high loadings were defined.
The method can be applied to commercial powders, and the treated powders can be used directly in conventional thermal spray processes;
BCC Research estimates that the global consumption of advanced and nanoscale ceramic powders will rise from $9 billion in 2013 to $12.1 billion in 2018, a compound annual growth rate (CAGR) of 6.2% over the next five years.
The powder refers to advanced materials applications mainly in need of thermal protection through coatings.
The process ensures manufacture of composite metal/ceramic powders consisting of ceramic core encapsulated completely into uniform metal shell. The metal content in the powder can be controlled in a rather wide range (up to 30 wt.%). The particle size and shape are suitable for direct application in thermal spray processes (Annexes I-III). All starting materials (including ceramic core powders) can be purchased in the market and do not require special preparation procedures.
Compared to the state of the art deposition process of the intermediate bond coat layers (spraying powder mixtures), such powders are expected to ensure TBCs with the improved performance due to more homogeneous distribution of ceramic particles in metal matrix without remarkable segregation

Key Exploitable Result 2 Protocol for the development if improved TBCs by dry methods
Materials and optimized methods for the development of improved TBCs by dry methods are filed in this protocol. Proper manifestation for the selection of commercial products and under development materials and tools is also provided. Selection of appropriate coating method with optimized conditions, utilizing nanostructured/nanocomposite materials to create smart coatings with tunable nano / microstructure, graded or hierarchical structure. The purpose of this protocol is to develop a manufacturing process protocols and control, using optimized conditions for improved Thermal Barrier Coatings (TBCs) by means of dry methods.

Innovativeness introduced compared to already existing Products/Services
Optimized process parameters for various dry thermal spray deposition methods described within the Project. This is a Unique process for the proposed materials.
The process refers to advanced materials applications in need of thermal protection through coatings. Industrial application are numerous. In principle all surfaces prone to thermal or friction wear.
As the need for materials operating in extreme conditions is increasing so is the need for this process.

Potential Impact:
TheBarCode project is focused to advance considerably the efficiency of power generation in gas turbine processes by the development of improved thermal barrier coated parts or components of significantly improved performance providing optimized process parameters.
The project addresses the following scientific and technological issues:
• New TBC formulations with long-term stability, more resistant under extremely severe operating conditions (e.g. creep, fatigue, thermal-mechanical fatigue, oxidation and their interactions, at high service temperatures) thus the maximum application temperature will be higher and so performance during energy generation.
• Flexible and cost effective production systems based mainly on thermal spray (SPS/SPPS, APS, HVOF) but also EB-PVD in order to realize patterned functional TBCs with improved properties.
• Application of structural analysis and fluid simulation software, including radiation, combustion, heat transfer, fluid-structure interactions and conjugate heat transfer models for the development of detailed models for the operational performance and prediction of spallation phenomena and failure.
• Environmentally friendly process using chemical formulations free of hazardous and toxic solvents.
The European Council in 2007 adopted ambitious energy and climate change objectives for 2020 – to reduce greenhouse gas emissions by 20%, rising to 30% if the conditions are right, to increase the share of renewable energy to 20%, and to make a 20% improvement in energy efficiency. Achieving an energyefficient Europe is the 1st out of the 5 priorities of the new energy strategy. However energy demands in EU are rising (2%/year) and there are no indications that this demand will be curbed significantly in the short or medium term despite the measures adopted. At the same time the electricity generation capacity that holds more than 20 % of production is aging and a large number of power plants are scheduled for retirement. Capacity planning for new power generation facilities has its basis in economic criteria and energy policy goals of the EU. Concerning the future fuel mix energy outlookers tend to agree that the contribution of renewable energy sources will not dominate before 2030 while the nuclear power plant capacity will shrink or remain the same. Therefore fossil fuel power plants will remain the backbone of the EU energy generating sector until at list 2030. In 2020 around 40 % of electricity will still be produced by conventional power plants. The aim of this project is the development of materials, methods and models suitable to fabricate, monitor, evaluate and predict the performance and overall energy efficiency of novel thermal barrier coatings for energy generative systems. By the radical improvement of the performance (working temperature, lifetime etc) of materials “in service”, by the application of novel thermal barrier coatings, structural design and computational fluid simulations a significant improvement in energy efficiency and cost effectiveness can be achieved.

Background of the project consortium
The BarCode Consortium encompasses a group of organisations characterised by their scientific expertise, proven track record, capability to effectively cooperate (arising from experience in previous projects in several cases), and enthusiasm towards the ultimate objectives of the project.
The work has been built with interdisciplinary collaboration as one of the main strengths and drivers of the project. Therefore, the involvement of partners in the different tasks has been agreed upon taking into account the diverse valuable contributions that each partner could make to the whole range of activities foreseen. This is the result of an optimal responsibility assignment, in which expertise and capabilities of all participants are intended to be taken advantage of for maximum global effect.
The project partners already have advanced complementary knowledge, techniques and expertise. The consortium is well balanced designed to satisfy all project objectives and deliver concrete final products (materials, models, parts, S/W tools, field testing). It comprises 2 universities, 4 research institutes responsible for materials preparation, characterization and testing, a high-tech SME (NUMECA): a leading software developer and solution provider for advanced modelling and optimisation services for the engineering and power generation industries, an enterprise (MIRTEC (CERECO Branch)): a contract research organisation, with expertise in powder processing and plasma coatings, a company (ELEMENT): leading international provider of innovative engineering solutions specialising in materials and component testing, failure and design analysis and durability assessment, a high-tech SME (PLASMA): highly specialized with dedicated activity in the processing and manufacturing of hard coatings by thermal plasma processes, an innovative SME (OSM): specialized in risks and knowledge management, technological assessment as well as LCA, technology & innovation implementation, dissemination and networking. The cornerstone of the private sector is the end user involved (SATURN); high-efficiency gas turbines for power industry and gas pumping, gas turbine electric power stations and parts and components for such engines. These partners will ensure industrial relevance and impact of the research effort with a clear market orientation and secured exploitation of the results. The opportunity of involving SMEs has been well addressed with SMEs having a core role in the project that in terms of finances corresponds to 20% of the requested EC contribution.
The R&D innovation edge in the Project will emerge from the high level commitment of two Universities (TEISTE, TUC) and four specialized research centres (BIC, PMI, IPR, INCAS) with state-of-the-art knowledge and experimental infrastructure, that provide a sound scientific knowledge base for materials synthesis, characterization and fundamental studies providing the necessary input for model development. A critical number of partners has collaborated successfully in consortiums or bilaterally in the near past or currently is, ensuring on a project basis a standard quality of communication and efficiency e.g. TEISTE with TUC, MIRTEC(CERECO),BIC; BIC with PMI, SATURN, PMI-IPR, TEISTE with INCAS – PLASMA; MIRTEC(CERECO) with ELEMENT etc
No partner is found committed in a technical Task solely without the contribution or participation of a collaborator, thus minimizing the risk allocation and ensuring the completion of objectives set in the work-programme.
THEBARCODE is strategic from the industrial point of view, while industry and market needs should be the drivers of development and integration of the proposed technologies.
TheBarCode approach will result also in an increase of turnover for the European energy sector, through new investments which promote energy efficient solutions.
Environmental friendly materials synthesis methods were followed, such as the polymerized precursor route, sol-gel citrate route, mechanochemistry, microwave-assisted combustion method, supercritical hydrolysis, etc. Composites and nanonocompsites of various materials were synthesized and tested against the typical protocols for top coat materials. Examples include perovskites (LaAlO3), pyrochlores (La2Zr2O7, Sm2Zr2O7), hexaaluminates (LaAl11O18, LaMgAl11O19), LAMOX (La2Mo2O9, La2MoWO9, etc), nanocomposites (LaAlO3 + La2Zr2O7, doped zirconia powder cladded with Ni and Co).
Preparation procedures were optimized to provide nanocrystallinity of complex oxides, uniformity of their phase composition and spatial uniformity of nanoparticles distribution in nanocomposites.
Genesis of the phase composition and real structure of complex oxides and their nanocomposites as a function of the synthesis procedure and its parameters was studied in detail. Disordering of the bulk and surface layers of these materials, high density of domain boundaries and remaining porosity required for good thermal insulation were demonstrated. Materials were prepared in required amounts for their characterization and supporting on substrates. Their thermal expansion and thermal conduction characteristics were estimated and shown to meet the targets.
For supporting these materials on substrates by such methods as Liquid Plasma Spaying, dry plasma spraying, detonation spraying, electrophoretic deposition, slip casting required procedures for materials processing to produce sols in water (or in organic solvents) as well as powders with required sizes of particles were developed. Batches of feedstocks were prepared and transferred to partners for supporting, which was made successfully.
Successful dispersion of the consortium synthesized innovative materials in water was attained, allowing the use of micron or less sized powders to be deposited as TBC layers through the LiquidPlasma Spray technique.
Various ZrO2-based thermal spray powders were modified via cladding by Ni and Co in order to create an intermediate layer between BC and TC for the extended TBC lifetime. The processes were scaled up to the pilot-scale level. The thermal-diffusion alloying process was applied for doping the powders by Al and Cr. MCrAlY alloy powders for BC deposition were properly doped.
Techniques to measure the mechanical properties of the TBC constituent materials have been developed and experiments performed to measure the properties at elevated temperatures to which the TBC’s are subjected to during operations. Friction and wear properties of the TBC’s have been measured and friction coefficient and wear factors calculated from the experimental data.
Techniques have been developed and applied to measure the fracture properties of the TBC’s developed as part of the project. Two methods have been employed: (a) micro-indentation; and (b) modified three point bend test. Considerable effort was required to set up the test and to obtain the necessary fracture data. The micro-indentation test provides the fracture data for the top coat itself whereas the three point bend test provides fracture data at the interface between the top coat and the TGO or the bond coat. Because of very small and uneven areas of top coats for the micro-indentation tests considerable scatter is found in the results obtained. More consistent results were obtained from the three point bend tests. As with any fracture testing method a large number of tests are required to minimize the scatter and increase confidence levels.
Deposition parameters were optimized. Thorough investigation of the mechanical properties, effect of annealing procedure, thermal cycling and thermal shock behavior of the developed TBC was performed. The resulted behavior of the TBC systems led to the selection of five most promising different systems by the consortium to be deposited on the real parts for pilot scale testing by the end user.
Models which allow for crack growth analysis to be performed have also been developed. Different methods of obtaining strain energy release rate as a function of thermal cycles have been assessed. A sensitivity analysis has been performed to assess the influence of different parameters. The models developed can be employed to predict failure and the life of TBC’s based on fracture mechanics principles. The model for lifetime prediction has been developed and tested on data coming from the literature. Then, it has been applied on the available experimental data showing a good correlation between the computed number of cycles and the real one obtained during the testing. Simulations show good agreement with the experimental data for temperature distribution on the external part of the blade. Furthermore, the analysis of the database allows to quantify the impact of the TBC thickness and average thermal conductivity on the thermal performances.
TBCs developed within the Project with active participation of SICA partners outperformed the SoA TBC scheme used by the end user, at temperature higher than the service limits of the SoA materials. The five most promising TBC systems developed within the Project attained better-off performance against thermal cycling and thermal shock testing at temperatures higher than 1200 oC.
The R&D phase is complete with a demonstrator on pilot scale. It is suggested to start production of powders for commercial use and offer spraying as a service. Since the demo exists there are no major costs for the manufacturing. Production will be based according to orders with an advance payment so the market placement risks are minor.
Complex oxides and mixtures are available in the market in limited amounts. It is expected however that their use will increase in the longer term.

The world nanopowder production is distributed unevenly throughout countries. Only industrially developed countries are now producing nanomaterials in commercially reasonable amounts. Most producing countries depend heavily on the import of feedstock. Many countries such as Brazil, South Africa, Russia and Australia are major producers of feedstock for nanoproducts but they do not produce nanoparticles in substantial ammounts.
However, the USA produces most of them in sufficient amounts to meet its own demands.
European producers of nanopowders do not produce them in sufficient amounts for domestic consumption, and production of some special powders that become increasingly important is either non-existent or minimal. As a result, European consumers import large amounts of various nanopowders from North America.

Asian producers specialize mostly in the production of a few types of nanopowders, but they can supply them to the neighboring countries thereby reducing their demand for North-American or European products.
The largest share in the structure of nanopowder output belongs to metal oxides. Metal powder mixtures account for the minimum share in the nanopowder market structure. Demand for powders that act as thermal barrier coatings also is increasing together with new applications especially in the energy sector and the quest for renewable resources.

TheBarCode approach will result also in an increase of turnover for the European energy sector, through new investments which promote energy efficient solutions.

List of Websites:
www.thebarcode.eu

Vassilis Stathopoulos
Associate Professor
Department of Electrical Engineering
School of Technological Applications
Technological Educational Institute of Sterea Ellada
34400 Psachna, Chalkida, Greece

Tel. +302228099621 (office) | +302228099688 (lab)

Contact

Vassilis Stathopoulos, (Head of Laboratory of Chemistry and Materials Engineering)
Tel.: +306972915863
E-mail
Record Number: 188142 / Last updated on: 2016-08-11