SUPER LIGHT-WEIGHT THERMAL PROTECTION SYSTEM FOR SPACE APPLICATION
The main challenge of the project is to develop a super-light, corrosion and oxidation resistant TPS by combining the advantages of metallic and ceramic materials in a single system. This will be achieved by joining a novel metallic frame with non-metallic materials (for example C/SiC and C/C), construction elements made of UHTC (system ZrB2-SiC) and new high-temperature alloys coated with UHTC composites. Particularly, the 3 direction of works are envisaged:
1) development of new powder alloys on the base of Ni/Cr and Nb for the frame of TPS;
2) development of reusable light weight multilayer metallic TPS sandwiches;
3) investigation of erosion-resistant UHTC bulk materials in the ZrB2-SiC system and coating of metallic and non-metallic materials with the most suitable UHTC compositions.
The developed TPS will be significantly lighter than any existing TPS (under 10 kg/m2) thus reducing the cost of delivering a payload to orbit and volume of emission, guarantee reliable thermal protection in the entire range of working temperatures, possess improved mechanical and durability properties.
FUNDACION TECNALIA RESEARCH & INNOVATION
Parque Cientifico Y Tecnologico De Bizkaia, Astondo Bidea, Edificio 700
48160 Derio Bizkaia
€ 329 990
Maria Parco (Dr)
Sort by EU Contribution
FRANTSEVICH INSTITUTE FOR PROBLEMS OF MATERIALS SCIENCE OF NATIONAL ACADEMY OF SCIENCE OF UKRAINE
€ 397 200
"DERZHAVNE PIDPRIEMSTVO ""KONSTRUKTORSKE BYURO ""PIVDENIE"" IM. M.K.YANGELYA"""
€ 350 356
SPACE RESEARCH INSTITUTE OF THE NATIONAL ACADEMY OF SCIENCES OF UKRAINE AND THE NATIONAL SPACE AGENCY OF UKRAINE
€ 143 010
INSTITUT ELEKTROZVARYUVANNYA IM.E.O. PATONA NACIONALNOI AKADEMII NAUK UKRAINY
€ 120 001
CONSIGLIO NAZIONALE DELLE RICERCHE
€ 205 621
ECM SPACE TECHNOLOGIES GMBH
€ 178 000
DEUTSCHES ZENTRUM FUER LUFT - UND RAUMFAHRT EV
€ 273 185
Grant agreement ID: 607182
25 April 2014
1 September 2017
€ 2 741 034,20
€ 1 997 363
FUNDACION TECNALIA RESEARCH & INNOVATION
Final Report Summary - LIGHT-TPS (SUPER LIGHT-WEIGHT THERMAL PROTECTION SYSTEM FOR SPACE APPLICATION)
The future development of near space research and exploration is unthinkable without developing a new generation of reusable space vehicles. All countries active in space have extensively invested in R&D programmes aimed at creating reusable spacecrafts (e.g. X-38 Crew Return Vehicle (USA), SHEFEX (DLR, Germany), Foton (Russia), USV (Italy), etc.), which would overcome the limitations of former reusable space systems (RSS), such as: high weight and size leading to extremely high costs of a mission; high maintenance costs and insufficient reliability.
The basic underlining idea of the project was to combine principle advantages of new metallic and ceramic materials in a single thermal protection system by combining metallic TPS with non-metallic materials (e.g. C/SiC and C/C) and construction elements made of UHTC and heat resistant alloys, coated by composites on the basis of UHTC. In order to gain the highest possible TRL within the project time frame, a decision was done to guide the developments according to two different application scenarios:
A. Light-TPS systems based on new metal frame and NiCr- or Nb- alloys, supposed to be used in flat surfaces where the operating temperatures do not exceed 1100°C and with a specific weight < 10Kg/m2.
B. Light-TPS systems based on non-metallic structures, addressed to sharp components, where the operating temperatures overpass 1600°C. For this purpose, highly refractory ceramics and coatings on its basis for the thermal protection of elements made of C/SiC and C/C shall be developed. Additionally, the possibility to apply a graded metal-UHTC layer on Nb base substrates for oxidation/erosion protection shall be explored.
Scenario A: With focus on scenario A, basic requirements to reusable spacecrafts (RSC) have been collected for orbiter vehicles like Space Shuttle (USA), Buran (USSR), Hopper, Hermes (ESA), as well as for multiple TPS.
Main achieved results in scenario A: In first place, new heat resistant oxide dispersion-strengthened powdered and sintered alloys on the basis of NiCr and Nb with densities down to 7.450 and 5.558 g/cm3, respectively, have been developed. Relevant thermo-mechanical properties have been characterized within the temperature range of 20 -1200 °С. Developed materials have been hot/cold rolled to foils with thicknesses down to 0.06 mm. Based on experimental data and design activities, a new TPS design in size of 300x300 mm was developed that consists of four single tiles of 150х150 mm each. The external panel is a three-layer honeycomb manufactured in the developed Ni-Cr-Al alloy. The same consists of top shell, honeycomb core with hexagonal cell and bottom shell. The single tiles junction is achieved with U- shaped profiles. The stands are made as a unit bracket with four supports. The single tile structure is strengthened at the corners by 4 angles, which are designed for load transfer from the tile external shell to supporting node stand. Two TPS mock-ups have been manufactured using the developed NiCr alloy and corresponding structural elements: 1) 1st mock-up in size of 310 x 150 mm, consisting of two tiles of 150 x 150 mm each; 2) 2nd mock-up in size of 165 x 165 mm, consisting of four tiles of 75 x 75 mm each. The 1st mock-up was tested under complex mechanical loading conditions imitating the expected operational loads, while the 2nd mock-up was aimed to determine the thermo-mechanical strength of TPS structure. The developed TPS structure has been qualified in TRL4.
Scenario B: In order to stablish reference service parameters for demonstration of the UHTCs to be developed in the frame of the project, the heating distribution environment and pressure in the nose cap of the re-entry vehicle X-38 have been analysed in addition to the requirements collected for scenario A. The trajectory of X 38 is similar to those of Space Shuttle, Buran, Hopper and Hermes.
Main achieved results in scenario B: Alternative atmospheric thermal spray depositions processes were investigated in the frame of LIGHT-TPS, leading to homogeneous and dense UHTC coatings on the basis of ZrB2-SiC-WC, ZrB2-MoSi2 and ZrB2-20SiC-10AlN. Accelerated oxidation tests, performed under hypersonic combustions flames and with a Plasma Wind Tunnel facility, have shown the potential of these UHTC coatings for the oxidation protection of non-oxide CMC substrates (C/C and C/SiC composites). Single UHTC on the basis of ZrB2-3SiC-5WC and ZrB2-20SiC-10AlN have been deposited on C/C and tested in Plasma Wind Tunnel test facility at probe stagnation pressures around ~23-25 mbar, surface temperatures between ~ 1800-2000ºC and an exposure time between 5-6 min. The composition ZrB2-20SiC-10AlN showed a higher stability under selected test conditions and preserved its integrity even though a clear oxidation layer is present.
Project Context and Objectives:
The future development of near space research and exploration is unthinkable without developing a new generation of reusable space vehicles. All countries active in space have extensively invested in R&D programmes aimed at creating reusable spacecrafts (e.g. X-38 Crew Return Vehicle (USA), SHEFEX (DLR, Germany), Foton (Russia), USV (Italy), etc.), which would overcome the limitations of former reusable space systems (RSS), such as, for instance, the Space Shuttle, notably:
– High weight and size leading to extremely high costs of a mission;
– High maintenance costs;
– Insufficient reliability.
Future RSS will require greatly improved Thermal Protection Systems (TPS) to achieve the ambitious goal of reducing the cost of delivering a payload to orbit by an order of magnitude. An improved TPS, suitable for RSS, must not only perform its primary function of maintaining the underlying vehicle structure within acceptable temperature limits, but must also be durable, operable, cost effective, and light. Durability implies resistance to damage from such environmental threats as handling, low-speed impact, hypervelocity impact, and rain impact as well as the ability to tolerate some level of damage without requiring repair. Operability includes ease of removal, replacement and repair, and minimal maintenance between flights (e.g. minimize or eliminate waterproofing). Cost effectiveness considerations include initial development, fabrication and installation costs, and maintenance costs over the life of the vehicle as well as the impact of TPS on the vehicle performance. The mass of the TPS and limitations on all-weather flying capability significantly affect the performance of the vehicle.
The wide range of temperatures and conditions to which the thermal protection is exposed on the different positions of a RSS impose high demands on the materials for its production. For areas with surface temperatures around 1100-1200°C, a metallic TPS based on honeycomb constructions is the preferred solution. Currently, the most promising high temperature alloys are those based on either nickel (PM-1000 and domestic Н80Х20 nichrome) or iron (PM-2000), with the heat resistance of PM-2000 being somewhat lower than that of PM-1000 at almost the same refractoriness. However, the main disadvantages of existing TPS based out of such metallic alloys are the significant weight and insufficient lifetime, due to the degradation and corrosion of the metal.
On the other side, thanks to their high strength, high hardness, superior fracture toughness, good thermal shock resistance and low density at elevated temperature, carbon-based Ceramic Matrix Composites (CMCs) are the standard choice for service temperatures in the range of 1260-1650 ºС. In this temperature range, TPSs on the basis of carbon-carbon composites (C/C) reliably operate by the principle of "radiation cooling." The disadvantage of this materials class is the low resistance to high temperature oxidation. All oxidation protections for C/Cs basically include three components to protect against oxidation attack over long - term applications, i.e. inner bulk protection, outer multilayer CVD - coating, and finally a glass sealing layer serving as a surface coating. For high temperature applications, bulk treatments are often performed with silicon to form SiC, which possesses superior oxidation protection behavior compared to salt impregnations. Low surface temperatures and high oxygen partial pressures promote the formation of a glassy SiO2 layer over the surface of these materials. This situation is often referred to as passive oxidation and often corresponds to a net mass increase. Nevertheless, higher temperatures and lower pressures can lead, instead, to the volatilization of silicon oxide products into the gas phase, hence a net mass loss. This scenario, referred to as active oxidation, can become a harmful condition for the integrity of the TPS. The application of ultra-high-temperature ceramics (UHTCs) coatings might be an effective way to reach the goal of improving the in-service performance of CMC structures at temperatures of above 1600ºC. This class of materials possesses a unique combination of physic-chemical properties such as the highest melting points of any groups of materials, low creeping rate, good chemical stability in aggressive environment and high thermal conductivity that makes them specifically suited for application in the aerospace sector.
In this sense, new materials and construction technologies are needed in order to overcome the limitations of state-of-the-art TPSs, in particular:
– Lighter alloys with higher thermal, corrosion and oxidation resistance at temperatures around 1100-1200 °C (basis for metallic TPS);
– New UTHC materials with superior oxidation and erosion resistances at temperatures close to 2000 °C and coating technologies for depositing the same on metallic and non-metallic materials;
– Better construction technologies (e.g. new welding technologies for the production of honeycomb sandwich panels) enabling the implementation of new high temperature metallic alloys.
The LIGHT-TPS project aimed at developing innovative materials and manufacturing technologies for the fabrication of a new generation thermal protection systems for future reusable space systems. The main challenge of the project was to develop a super-light, corrosion and oxidation resistant TPS by combining the advantages of metallic and ceramic materials in a single system. Particularly, three main research pillars have been envisaged:
1) Development of new high temperature alloys on the basis of Ni/Cr and Nb for the frame of the TPS;
2) Development of reusable light weight multilayer TPS structure out of the developed NiCr- or Nb- base alloys;
3) Investigation of erosion-resistant UHTCs bulk materials in the ZrB2-SiC and ZrB2-MoSi2 systems and development of erosion/oxidation protective coatings on either metallic and non-metallic materials with the most suitable UHTC compositions.
The developed TPS shall be significantly lighter than any existing TPS (under 10 kg/m2) thus reducing the cost of delivering a payload to orbit and volume of emission, guarantee reliable thermal protection in the entire range of working temperatures, possess improved mechanical and durability properties.
In order to attain the overall project goal, the following technical objectives have been pursued:
O1. To study and systemize the system requirements for the TPS development based on at least 2 of the most advanced European projects concerned with the development of reusable spacecrafts and/or other space systems using TPS.
O2. To research the mechanisms of secondary structures formation under high-temperature oxidation conditions on the working surface of traditional nickel-chromium alloys (reference material is the YUIPMS alloy developed by YUZHNOYE) in correlation with the manufacturing technology with the aim of increasing their operational characteristics.
O3. To develop the manufacturing technologies for a new alloy based on Niobium, which shall possess better exploitation characteristics (i.e. specific weight of 5830–6000 kg/m3 and improved corrosion resistance).
O4. To investigate the respective physical processes and to develop new oxidation/erosion protective coatings out of UHTC composites based on the ZrB2-SiC systems, suitable for applications at temperatures up to 2000oC. To investigate the processes of the secondary structures development on such surfaces during exploitation.
O5. To develop realistic prototypes of the TPS elements incorporating new materials, technologies and processes. To carry out the system of tests and evaluation in order to estimate to what extent the technical requirements set at the beginning of the project were met.
O6. To make the project outcomes available to the research communities and potential users (developers of future RSS and respective technologies). To ensure a proper identification, documentation and protection of new knowledge and its transfer to the industry.
In the following, main activities performed inside the different work packages (WP) leading with the technical work and the most outstanding results collected in each case are summarized.
➢ WP1. Collection of requirements:
The first step of the project consisted of the collection of user requirements. Based on existing literature and practical data, technical requirements to the materials and elements of the TPS to be developed in the project have been formulated. A list of key technical, economic and operational requirements has been formulated.
Project results shall be validated in two scenarios:
a) Light-TPS with metal frame out new NiCr- or Nb- base alloys (TPS design/construction/ground test in charge of YUZHNOYE). Service temperature shall be limited to 1100°C due to the NiCr- or Nb- alloy.
b) New UHTC materials in form of a bulk and/or coating on non-metallic structures (definition of scenario done by DLR). Service temperature close to 2000°C.
Based on the analysis of the external influences at maximum levels, it was shown that the trajectories of orbital vehicles like the Space Shuttle (USA), Buran (USSR), Hopper or Hermes (ESA) are identical and any of them can be used as a model to calculate temperature changes and pressure in timing. A conventional trajectory and set of influence levels has been defined for the development of the metallic TPS. In the same way, the volume of ground tests has been defined for the metallic TPS.
➢ WP2. Development of powder alloys:
Task 2.1 - Development of alloys on the basis of NiCr:
Two materials on the basis of nichrome with the following compositions have been developed by IPMS:
- Ni - the base, Cr - 20 %, Al- 5.7 %, Yttrium, oxide - 1 %;
- Ni - the base, Cr - 20 %, Al- 5.95 %, Ti – 1%, Yttrium, oxide - 1 %.
The technology for manufacturing preforms with a relative density of more than 92 % has been developed. Theoretical density of first alloy is equal 7.5 g/cm3, while the corresponding value for the second composition amounts to 7.44 g/cm3.
Ingots out of the developed NiCr alloys have been rolled to sheets with thickness between 0.5 mm till 0.05 mm following hot and cold-rolling procedures developed by IPMS. The physical-mechanical and functional properties of rolled foils have been characterized. Measured properties meet the technical requirements for the bulk samples. It was shown that a moderate porosity is found in the microstructure of Ni-Cr alloy foil, which is concentrated predominantly in the material subsurface layers. On the other side, the Ni-20Cr-6Al alloy in as-delivered condition has significant work-hardening as result of rolling process. Average microhardness values amount to Н = 2.946 GPa, with a ductility factor of К = 0.660.
Additionally, following simulation activities have been performed by SRI:
1. An analysis and optimization of the TPS temperature fields during the diffusion welding process have been conducted.
2. 3-dimensional heat transfer problems were modeled with the continuous state space equation through mode reduction technique. After deriving a solution in a frequency-domain, an observer was designed with the Butterworth low pass filter. And then, an adaptation algorithm was applied so as to estimate the time-variant parameter in actual thermal process.
3. A methodology for localizing fastener failure in a TPS was developed, utilizing an experimentally validated finite element model.
4. The inverse optimization problem implemented in the first level of experimental validation demonstrated excellent agreement between the finite element model and the experimental results.
5. An analysis of the kinetics of densification process occurring in powder alloys based on the detailed population balance approach has been conducted. It has been shown that the densification kinetics is described approximately by a root dependence on the sintering time, except the final stage of the densification process.
6. The algorithm for finding the distribution of temperature fields inside the TPS has been developed. It has been shown that the heat inside the TPS is transferred mainly along the metallic frames. The estimated time of balancing the temperature and the thermal flow in the TPS is 10-100s.
Task 2.2 - Development of alloys on the basis of Nb:
A new heat resistant dispersion-strengthened alloy on the basis of niobium with reduced density (5.5 -5.7 g/cm3) was developed by IPMS. Composition of developed Nb-based alloy: Ti - 45±1%, Al, - 6±0.5%, Y2O3 - 1±0.5%, the rest is Nb, possible introduction of Zr – 1.5±0.5% and Cr – 1±0.25%.
Technology for reaction sintering of this material was implemented. The heat resistance of the alloy was studied. It was shown that the material fulfils the requirements linked to the expected service conditions at 1200 ºС, thus withstanding 100 cycles of heating and cooling to room temperature. Tests have shown that material loss is equal 1 % of its mass under the cyclic heat loadings. The developed material has characteristics corresponding to niobium alloys and can operate continuously at a temperature of 1200 °C, which exceeds analogues materials. In the initial condition, the niobium alloy has an average hardness value of Hm = 5.388 GPa with a ductility factor of K = 0.814.
Task 2.3 - High temperature tests of the samples of Ni-Cr and Nb alloys under the conditions of oven, convection and radiation heating:
Heat resistance of the alloys was studied under the effect of oven, radiation and convective heating (most outstanding results have been already commented above). It was shown that annealing of Ni-20Cr-6Al alloy does not lead to any significant changes of its structure or chemical composition. On the other side, annealing of the alloy at Т = 1200 ºС for 20 minutes in vacuum leads to a significant increase of the alloy microhardness from H = 2.946 GPa up to H = 5.109 GPa. By the results of micromechanical testing, as light decrease of average values of niobium alloy microhardness from Hm = 5.388 GPa to Hm = 5.263 GPa and a slight increase of its ductility factor from K = 0.814 to K = 0.819 are noted after annealing.
The implementation of Ni intermediated layers (deposited by EB-PVD) on the joint surface of Ni-Cr alloy foils, was to found to be a suitable solution for obtaining well-structured diffusion welding joints. A subsequent annealing in air at a temperature of 700 ºС for 50 hours, led to joints with chemical element distributions similar to those found in base metal.
➢ WP3. Development of super-light multilayer TPS:
Task 3.1 - Development of the construction and manufacturing technology for TPS:
The initially developed TPS design is a panel of 300 x 300 mm in size that consists of four single tiles of 150 х 150 mm each. The external panel is a three-layer honeycomb structure. The same consists of top shell, honeycomb core with hexagonal cells and bottom shell. The single tiles junction is achieved with U- shaped profiles. The stands are made as a unit bracket with four supports. The unit tile hardeners are 4 angles, which are designed for load transfer from the tile external shell to supporting node stand that has led to weight indexes increase.
In a following step, based on collected experimental data and simulation activities, YUZHNOYE optimized the design of the different TPS elements. In first place, the design of the honeycomb structure has been modified to fulfil the expected specific mass requirement, i.e. an area specific mass below 10 kg/m2. In the optimized configuration, the hexagonal cells are formed by ribs having a length equal to 15 mm and a thickness equal to 0.1 mm. On the other side, the four individual tiles are connected by linear double U-shaped connecting elements. The junctions of the four tiles (central part) are not connected to each other. Sealing is ensured by a freely embedded crossing between the double U-shaped connecting elements, that eliminates the rigid bond with the outer casing.
To prevent the cross-shaped sealing from falling out and the hot gases to flow into the central part of the structure, a special lining is being applied. Related strength calculations demonstrated the efficiency of the designed double U-shaped sealing as well as the suitability of the freely embedded cross-shaped plug which provides free movement of tiles under the temperature loads.
In relation to the development of the welding methods, following activities were performed by IEW:
1. The feasibility of using interlayers of different chemical composition for construction of diffusion welding joints was investigated, showing that application of Al/Ni and Cu/Ti multilayers by the EB-PVD technology promotes the formation of joint diffusion zones with higher level of microhardness. Application of interlayers based on porous foils from nickel, copper and cobalt, allows establishing physical contact of the joining surfaces, thus facilitating the diffusion processes and weld joint formation. Those joints produced using interlayers based on nickel and copper have a defect-free structure.
2. The diffusion welding of the Nb-30Ti-6Al niobium alloy was investigated. It was shown that welding at a temperature of 900 ºС in combination with a pressure of 20 MPa provides the dissolution of the oxide film and the formation of common grains in the butt joint. Moreover, the application of a 20 μm thick interlayer from VT1 low alloy, promotes the formation of a defect free joint with several diffusion zones along the butt joint.
3. The manufacturing procedure of three-layer honeycomb panels was developed, which consists of: Cleaning of foil strips, shaping (profile formation), spot welding of the honeycomb block, grinding of end surfaces, application of intermediate layers and diffusion welding of shells with the honeycomb filler.
4. A special holder was designed and constructed to achieve a diffusion welding treatment of three-layer honeycomb panels under homogenous temperature and pressure conditions.
5. The behaviour of the three-layer panel under the heating conditions imposed by the vacuum diffusion welding treatment was investigated. It was shown that the behaviour of the panel is essentially influenced by a number of geometrical factors, namely imposed by the rectangular shape of three-layer panel, cylindrical shape of heaters, small panel height and its considerable surface area. In addition to the homogenization of temperature fields over the entire panel surface, it was demonstrated that shielding of all panel sides is a suitable way to prevent an excessive deformation of the panel during the welding process.
6. Three-layer honeycomb panels in size of 150 x 150 mm and 72 x 72 mm, out of the developed Ni-20Cr-6Al and Nb-30Ti-6Al alloys, were manufactured by diffusion welding at IEW and delivered to YUZHNOYE for TPS demonstrators assembly and ground testing.
Task 3.2 - Manufacturing of TPS prototypes for the system of pre-flight ground testing:
In order to integrate the different elements into a single mockup (following the initial design of 300 x 300 mm in size), various welding methods were investigated, including laser welding, micro-plasma welding, electron-beam welding and argon-arc welding. All these methods showed a number of disadvantages and didn´t provide good quality joints. Satisfactory results were obtained in a following stage with the use of diffusion welding. Nevertheless, since the diffusion welding facility available in the consortium was limited to laboratory prototypes with maximal dimensions of 150 x 150 mm, a decision was done to scale down the design of the final TPS prototype.
Theoretical computational analysis of the strain-stress state in the initial TPS design (300 x 300 mm) showed that the most loaded areas correspond to the welding points on either U-shaped sealings or the welding points of bearing supports. Based on these calculations, a central fraction of 150 x 150 mm from the initial design shall already contain all critical structural elements without changing their dimensions. Consequently, operational life tests conducted on such a down scaled mockup, which fully technologically and structurally conform to the most loaded part of 300 x 300 mm mockup, shall fairly represent the service performance of the initial “full scaled” TPS design.
Optimized process parameters for diffusion welding were stablished accordingly for the down-sized TPS elements. A technology to integrate separate elements into a single structure was developed. The technologies of manufacturing the individual structural elements using stamping and hydro-jet cutting were also developed.
Two TPS mock-ups have been manufactured out of the developed NiCr alloy and corresponding structural elements: 1st mock-up in size of 310 x 150 mm, consisting of two tiles of 150 x 150 mm each; 2nd mock-up in size of 165 x 165 mm, consisting of four tiles of 75 x 75 mm each.
Task 3.3 - Ground tests of TPS:
A complex ground experimental test campaign was carried out according to the test program developed at an initial stage of the project.
In first place, the properties of the heat-resistant alloy on the basis of Ni-Cr-Al were investigated up to a temperature of 1200 ºC. The results of the alloy tests performed in air do not defer from those obtained in vacuum, thus indicating the high heat resistance of the alloys, which excludes the impact of the medium onto the test results. For the same temperature range, the properties and endurance of the high-temperature thermal insulation material was investigated. The implemented thermal insulation blocks have been developed by YUZHNOYE and are composed of silicon oxide fibres (80-85%) with 2-3 microns in diameter and a silica gel binder. With a density of 100 kg/m3 and a thermal conductivity around 0.212 W/(m·K) at 1100°C, this material is lighter and features over better weight specific insulation properties than existing space-qualified thermal insulation materials used in reference space programmes like Buran (i.e. ТЗМК-10 and ТЗМК-25). This material features also over a very low thermal expansion coefficient, α = 0.5 x 10-6 1/К. It is estimated that a thickness of 33-37 mm will be sufficient to prevent overheating of the spacecraft. When the temperature of the heated surface reaches the 1100 °C, the temperature of the bottom surface does not exceed 250°C. Nevertheless, the homogeneity of the implemented insulation material should be further improved in order to achieve the mechanical strength and stability of the thermal properties required for spacecraft applications.
On the other side, the strength of the soldered joints within the different metal structural elements was evaluated. As stated above, it was determined that for the purposes of integrating the shells (covering skin of the panel) and the honeycomb filler into a three-layer panel, it is expedient to use the diffusion welding technique. For this purpose, the implementation of EB-PVD deposited copper or nickel porous intermediate layers was found to be a good approach to obtain homogenous and well-structured weld joints. Studies were carried out in order to assess the applicability and efficiency of the U-shaped joint within an operating temperature range from 20 to 1100 ºC. The U-shaped joint retained its integrity and operability without visible defects during 50 thermal cycles. It was also experimentally proven that at the maximum operating temperature of 1100 ºC, the U-shaped joint is almost completely closed; during the tests the gap did not exceed 0.5 mm.
Tests simulating the operational conditions (during transportation, launch and flight within the injection segment) were conducted on the delivered mock-ups, which showed that the developed TPS structure is able to maintain its efficiency under the expected service conditions. The 1st mock-up in size of 310 x 150 mm (composed of two tiles of 150 x 150 mm each) was tested under complex mechanical loading conditions. The 2nd mock-up in size of 165 x 165 mm (composed of four tiles of 75 x 75 mm each) was aimed at determining the thermo-mechanical strength of TPS structure. The developed TPS has been qualified in TRL4.
➢ WP4. Development of UHTC and gradient coatings on its basis:
Task 4.1 – Production and characterization of UHTCs:
At the beginning of the project, 12 different compositions from the ZrB2-SiC and ZrB2-MoSi2 systems were selected for synthesis and base-line characterization. The activities performed by CNR and IPMS revealed that the most promising sintering additives are WC or WSi2, B4C, MoSi2 and CrB2. They enabled to obtain bulks possessing room temperature strength in the order of 500-730 MPa and the lowest specific weight gain upon exposure to oxidation at 1500°C. In addition, it was concluded that little amount of SiO2-former, introduced as SiC or transition metal silicide, is beneficial to enable densification, to limit grains growth and to protect from oxidation. However, the amount of such SiO2-former has to be carefully controlled to limit the gas evolution in the subsurface scales and bubbles formation upon oxidation above 1600°C.
Further activities have been focused on the advanced thermo - mechanical characterization and oxidation resistance testing of selected UHTC composites in form of bulks. Following ceramic composites have been selected thanks to their outstanding refractoriness and oxidation performances:
Z-WS: ZrB2 + 15 vol% WSi2
ZS-WC(3): ZrB2 + 3 vol% SiC + 5 vol% WC
ZS-BC: ZrB2 + 15 vol% SiC + 5 vol% B4C
Z-MS: ZrB2 + 15 vol% MoSi2
ZS-CB: ZrB2 + 15 vol% SiC + 5 vol% CrB2
ZM-CB: ZrB2 + 15 vol% MoSi2 + 5 vol% CrB2
Tests were focused on the characterization of the flexural strength at high temperature in air, creep behaviour, coefficient of thermal expansion up to 1300°C and the thermal conductivity up to 2000°C. In addition, advanced oxidation tests have been carried out in a bottom-loading furnace at 1650°C for 15 minutes and repeated for 1-3 times. Most outstanding results collected are as following:
1. Bending strength of the samples was measured at 1400-1500°C. It remains almost constant compared to that at room temperature, one materials containing WC developed at CNR even enabled to keep a strength over 700 MPa when tested at 1500°C in air.
2. The creep of developed UHTCs was studied by indentation in the temperature range of 1200-2100 °С by compression at a pressure of 48 MPa. The creep of ZrB2 + 15 vol% SiC ceramics up to 2100 °С is under the conditions of super plasticity without material destruction up to 65% of deformation. Additives like tungsten silicide/carbide, boron carbide and chromium boride notably slow down the creep rate. For the developed materials, the creep starting temperature ranges 1760 - 1930 °С and is max for B4C and WC additions (1910 - 1930 °С). The activation energy of the creep process is in the range of 4.3-11.7 Ev. depending on the type of sintering additives.
3. Thermal cycling of developed ZrB2-MoSi2 composites in the flow of combustion products at T = 1400°С is accompanied by strength increasing in the range of 0-6000N due to the healing of surface defects in the stream and it is not accompanied by degradation of strength, which indicates a ceramics high thermal strength and thermal resistance.
4. Oxidation tests performed on samples produced at IPMS in non-isothermal conditions with heating rate of 3-4°C/min at 1250 and 1500°C for 30 minutes revealed that additive of MoSi2, CrB2 and SiC increase the oxidation resistance through the formation of a protective film of high-temperature phases. Ceramics obtained by vacuum hot pressing showed higher resistance to oxidation compared to ceramics obtained by hot pressing.
5. Oxidation tests, performed at CNR in a bottom-loading furnace at 1650°C for 15 minutes and repeated 3 times, revealed that ceramics obtained by vacuum hot pressing showed higher resistance to oxidation compared to the other ceramics obtained by hot pressing, MoSi2 enable to retain the pristine ZrB2 under a thin outermost SiO2 glassy layer. Among the investigated materials, none showed oxide spallation and the best results were achieved when ZrB2 was sintered with solely MoSi2 or simultaneous addition of MoSi2 and CrB2.
6. Selected ceramics have been subjected to thermal-erosion testing in a supersonic oxygen-fuel single phase flow. The composition ZrB2 - 15%MoSi2 - 5%CrB2 revealed the best stability. It was subjected to 7 heating cycles at a total duration of 1000 s and a temperature of 1671°C showing a mass loss of 201 mg/cm2, which corresponds to an average linear loss rate of 0.33 μm/s at a density of 6.1 g/cm3.
7. Thermal-erosion tests on UHTCs wedge shaped samples have been carried out within the supersonic flow of chemically neutral combustion products of a stoichiometric fuel-air mixture. The surface temperature reached 1650 - 1850 °С on the blade tips. The sample of ZrB2-MoSi2 composition was tested at the leading-edge temperatures between 1715°C and 1845°C in four heating cycles with a total duration of 3,236 seconds at a stagnation pressure of 0.38 MPa. The average temperature for the entire test period was 1800 ± 40 °C, the weight loss of the sample during the test was around 80.45 mg and the linear drift was about 0.2 mm. At the end of the tests, the ZrB2-MoSi2 sample has fully retained its operability. In comparison to the rest of the tested ceramic samples, this material configuration showed the highest resistance.
8. Thermal-erosion testing in two-phase flow has been done at flow angle of 30° and distance to the nozzle of 80 mm. At these conditions, the specimen (plates of 50 x 50 x 5 mm) surface temperature was around 1250 °С and 1350 °С. Alumina particles with a size distribution between 63 and 80 mm have been used as abrasive media (particles velocity was around 480 m/s). The coefficient of mass loss was around 2.8×10-4-3.8×10-4 kg/cm2.
9. The investigation of ascertained thermal- properties has been done within the temperature range of 25 - 2000 °С. Thermal conductivity of ZrB2-SiC ceramics of different compositions ranges 80-100 W/mK at room temperature and is around 42-60 W/mK at 1500°C, and 50-60 W/mK at 2000ºC. Heat capacity of ZrB2-SiC ceramics of different compositions rises from 0.46-0.51 J/gK at room temperature to about 0.7-0.8 J/gK at 2000ºC.
Task 4.2 – Development of coatings of UHTC and UHTC-based composites:
Based on results collected during the 1st Reporting Period and results arising in Task 4.1 CNR and IPMS further optimized the composition and quality of UHTC composite powders aimed at the production of coatings by thermal spraying. Significant efforts were dedicated by CNR to optimized the powder morphology and particle size distribution of powders out of the selected composition from the ZrB2-SiC system (i.e. ZrB2-5WC-3SiC). IPMS’ efforts were mainly focused on the development of powders on the basis of ZrB2-15MoSi2. At a later stage of the project, following alternative compositions with improved oxidations resistance were investigated: ZrB2-15MoSi2-5CrB2, ZrB2-20MoSi2-10AlN, ZrB2-20SiC-10AlN and ZrB2-15SiC-5CrB2. As result of these efforts, new one stage cost-competitive technologies for obtaining ZrB2 and composite powders to be applied as protective coatings has been developed by CNR and IPMS. Several batches of powders with the required size (10-40 and 64 -140 μm), compaction level and negligible oxygen content have been delivered to Tecnalia for coating deposition.
In relation to the development of coatings, TECNALIA and IPMS worked actively on the development of UHTC coatings following different approaches and implementing different deposition technologies. TECNALIA was mainly focused on the development of UHTC coatings by means of the Shroud Plasma Spray technique, dedicating some minor efforts to the development of graded and/or composite metallic-UHTC coating by High Velocity Oxy/Air Fuel spraying. IPMS worked mainly on the development of UHTC by detonation, plasma spraying and laser cladding. Some efforts were dedicated to the development graded metallic-UHTC coatings, implementing a High Velocity Air Fuel spraying system in this case. CNR extensively contributed to the microstructural and chemical characterization of as-sprayed coating and tested specimens. Most outstanding results are as following:
1. Homogenous UHTC coatings with compact structure based on compositions selected within Task 4.1 (ZrB2-15-20MoSi2 and ZrB2-5WC-3SiC) have been obtained by Tecnalia using a Shroud Plasma Spray (SPS) system. Coatings have been deposited on last state-of-the-art non-oxide CMC plates (C/C and C/C-SiC) in size of up to 50 x 50 x 5 mm. Even though at the expenses of a lower oxidation resistance, the adhesion strength to the C/C plate can potentially be improved through an infiltration post-treatment with Si. Coating thicknesses in the range of 200 – 400 µm have been investigated.
2. ZrB2-20SiC-10AlN was investigated as an alternative composition to reference UHTC appointed above, thus evidencing a better CTE match of the resulting coatings to the C/C-SiC base plate (no coating spallation observed) and a higher high-temperature corrosion resistance at temperatures above 1800ºC. A coating thickness around 200 µm might be sufficient to guarantee the oxidation protection of the CMC plate under re-entry conditions, if the base material is not exposed to the environment.
3. Under the responsibility of IPMS, homogenous UHTCs coatings based on ZrB2 with refractory additives of MoSi2, SiC and AlN on stainless still and C/C-SiC substrates have been obtained by the methods of HVAF and plasma spraying. The coating thickness amounted to 100-400 µm for coatings deposited by plasma spraying and 70-80 µm for the ones obtained by HVAF. The ZrB2 - 15MoSi2 coatings microhardness was around 6-18GPa that corresponds to those for bulk ceramics. The coatings have a rather high adhesion to the substrate.
4. The availability of laser technologies to obtain two layered UHTCs coatings on C/C substrates has been shown. The advantage of the laser coating deposition technology compared with the widely used thermal spray techniques is a high bond adhesion to the substrate and a high material utilization coefficient, small components oxidation, low ability to pore and fracture formation.
Task 4.3 – Advanced characterization of coatings:
According to the work plan, advanced characterization tests were performed by IPMS and DLR. Based on results collected in Task 4.1 and 4.2 the most promising UTHC material compositions either in form of bulk or as coatings on CMC base plates were manufactured by CNR, IPMS and TECNALIA for testing. Most outstanding results are as following:
1. Oxidation resistance tests with the Indutherm facility performed by DLR (at T ~ 1800°C and P= 200 mbar):
- An infiltration treatment of single ZrB2-5WC-3SiC layers deposited by SPS is a good prospective way to improve the adhesive strength of this layers to a C/C substrate, even though at the expenses of a lower oxidation resistance.
- The implementation of a thin intermediate PVD layer on the basis of AlN might be a good prospective way to improve the HT resistance of top ZrB2-15MoSi2 layer deposited by plasma spraying. A button scale sample prepared by IPMS was successfully tested under the selected conditions, with no evidences of spallation, cracks or defects both in the coating and the substrate, which testifies the high thermal protective properties of this coating. The oxide scale formed on the surface is mainly composed of ZrO2mon.). Because of the time constrain limitations, this sample configuration could not be tested within the PWT facility.
- A single ZrB2-20SiC-10AlN coating might be a good alternative to the initially selected UHTC compositions (ZrB2-5WC-3SiC and Zr2-15MoSi2), with superior oxidation and thermo-cycling resistance.
- Regarding the oxidation of bulk UHTCs, the production method in combination with the composition is the decisive factor for a well-functioning system. Bulk samples out of 80% ZrB2+ 15% MoSi2 + 5% CrB2 produced by vacuum hot pressing achieves the best results with respect to the stability of the material and stable oxidation layer.
2. Thermal erosion tests performed by IPMS in a supersonic flow of combustion products of either a kerosene (fuel) / air mixture or kerosene (fuel) / oxygen mixture:
- Single coatings based on reference compositions, namely ZrB2-15 MoSi2 and the ZrB2-3SiC-5WC, were tested under similar conditions. Both material compositions were deposited by SPS on C/C-SiC plates. Under heating, a constant cyclic change in the colour of the coatings of both compositions as well as in their radiation coefficients occur, like for the bulk UHTC, which testifies a similarity of the processes taking place on their surfaces. The measured emission coefficient on the ZrB2-15 MoSi2 coating ranged around έ = 0.61-0.71 while for the ZrB2-3SiC-5WC composition it was around έ = 0.48-0.69.
- Under the thermal erosive action of the air-kerosene flame (corresponding to a stagnation temperature of 2100 °С and a stagnation pressure of 0.45 MPa), the endurance of the C/C-SiC base plate was increased from 5 up to more than 20 minutes when applying a ZrB2-15MoSi2 coating, and up to 12 minutes in the case of the ZrB2 -3SiC-5WC coating. When performing the test with an oxygen-kerosene mixture (leading to a surface temperature of 1600 °C and partial pressures of molecular and atomic oxygen of P°O2 = 75 kPa and P°O = 6.6 kPa, respectively), the ZrB2-15 MoSi2 coating protected the CMC plate from destruction for at least 10 minutes, while the ZrB2-3SiC-5WC coating did it for 6.5 min.
- In addition, high-temperature tests of UHTC coatings out of the composition ZrB2-20SiC-20AlN (deposited by IPMS with an increased amount of AlN to obtain a stable oxide scale) were performed in the more severe conditions, i.e. using an oxygen-propane-butane torch, leading to a Tmax. ~ 2000 oC for a test duration of 900 seconds. For a functional thickness of 400 μm, this coating has been oxidized to a depth of 300 μm during the test, nevertheless with no spallation, cracks and defects neither in the coating nor in the substrate, which evidences the high temperature stability of the coating.
3. Plasma Wind Tunnel (PWT): Coatings on the basis of ZrB2-3SiC-5WC and ZrB2-20SiC-10AlN have been deposited on C/C plates and tested in a PWT facility (under subcontract at CIRA) at probe stagnation pressures around ~23-25 mbar and surface temperatures between ~ 1800 – 2000 °C for exposure times of roughly 5-6 min. The composition ZrB2-20SiC-10AlN showed a higher stability under selected test conditions and preserved its integrity even though a clear oxidation layer is present. Based on these observations, it can be stated that to achieve a sufficient oxidation protection during expected re-entry conditions, the TPS shall then either be coated completely with such an UHTC layer or a more oxidation resistant substrate should be used.
During an initial stage of the project materials specifications have been defined according to two different application scenarios:
A. Light-TPS systems based on new metal frame and NiCr- or Nb- alloys, supposed to be used in flat surfaces where the operating temperatures do not exceed 1100°C and with an area specific weight of less than 10Kg/m2.
B. Light-TPS systems based on non-metallic structures, addressed to sharp components, where the operating temperatures overpass 1600°C. For this purpose, highly refractory ceramics and coatings on its basis for the thermal protection of elements made of C/SiC and C/C shall be developed. Also the possibility to apply a graded metal-UHTC layer on Nb base substrates for oxidation/erosion protection shall be explored.
Scenario A: With focus on scenario A, basic requirements to reusable spacecrafts (RSC) have been collected for orbiter vehicles Space Shuttle (USA), Buran (USSR), Hopper, Hermes (ESA), as well as for multiple TPS, including the following items:
1. Number of re-starts.
2. Requirements to TPS materials.
3. Temperature conditions of casings.
4. External influences at all stages of operation.
5. Requirements to hydrophobic properties and non-hygroscopic (water-resisting).
6. Requirements to design – thermal protective design should be made as individual tiles.
7. Requirements for sealing between the individual panels.
8. Mounting methods for TPS to underlying structures.
9. Resistance requirements against microorganisms, bacteria, products of vital activity of living organisms (birds, mice, insects).
10. TPS verification under real simulation of its operation conditions.
11. Cost effectiveness of TPS.
Innovation brought in scenario A: Based on the analysis of the external influences at maximum levels, it is shown that the trajectories of orbital vehicles Space Shuttle (USA), Buran (USSR), Hopper and Hermes (ESA) are identical and any of them can be used as a model to calculate temperature changes and pressure in timing.
A conventional trajectory and set of influence levels have been selected for the development of the TPS in the frame of the LIGHT-TPS project. The volume of ground tests has also been defined.
An analysis of existing TPS for reusable spacecrafts has been performed. In general terms, major difficulties in designing such structures are large thermal expansions of the outer panel when heated, for which compensation can be performed by overhead cover (design of NASA Langley Research Center and Astrium) or spaced apart and between them a metal hardening is placed. In both cases, there is a problem of sealing the gaps, which decrease the reliability of the structure.
All analysed thermal protective structures are under development. For the technical realization of a cost-effective and reliable TPS, new perspective materials, new technologies and new design solutions are required.
Main achieved results in scenario A: In first place, new heat resistant oxide dispersion-strengthened powdered and sintered alloys on the basis of NiCr and Nb with densities down to 7.450 and 5.558 g/cm3, respectively, have been developed. Relevant thermo-mechanical properties have been characterized within the temperature range of 20 -1200 °С. Developed materials have been hot/cold rolled to foils with thicknesses down to 0.06 mm.
For the developed NiCr alloy, the tensile strength limit at room temperature amounted to 1020 MPa, while the corresponding value at 800 °С was equal to 542 MPa. In the case of the Nb alloy, the measured tensile strength limit at room temperature and at 1100 °С amounted to 900-1000 and to 80-110 MPa, respectively. On the other side, it has been established that the new NiCr- and Nb- base alloys feature over a good thermo-cycling resistance up to 1200 °С (> 100 cycles).
Two TPS mock-ups have been manufactured out of the developed NiCr alloy and corresponding structural elements: 1st mock-up in size of 310 x 150 mm, consisting of two tiles of 150 x 150 mm each; 2nd mock-up in size of 165 x 165 mm, consisting of four tiles of 75 x 75 mm each. The 1st mock-up was tested under complex mechanical loading conditions, selected to simulate the expected operational loads. The 2nd mock-up was aimed at determining the thermo-mechanical strength of TPS structure. The developed TPS has been qualified in TRL4.
Potential impact and use in scenario A: The project has developed a TPS for space applications, above all designed for a reusable spacecraft, which matches the expected weight requirement (<10 kg/m2). Nevertheless, in order to ensure the robustness and reliability of the system, following aspects will still require further R&D works: (1) The method for joining the honeycomb construction with upper and lower shells (to guarantee a better homogeneity throughout the joining surface) and (2) the technology for manufacturing the insulation blocks (to increase their mechanical strength and stability).
At the same time, in order to exploit the developed TPS, it will necessary to increase the TRL from 4 to at least 7 (system prototype demonstration in operational environment). This implies the readiness for flight test demonstration, which is in fact the final stage in the TPS development.
The developed TPS can be implemented in unmanned spacecrafts, capable of performing the gliding descent close to the trajectory followed by the Space Shuttle, Buran or any other reusable spacecraft under development.
Currently, there are several projects aimed at the development reusable space systems (RSS). This is exactly where the TPS developed within this project can be applied. The obtained results could quickly be adapted for exploitation in practically any RSS, e.g. Boeing X-37(B), CST-100, Dream Chaser, Space Ship Two, New Shepard (all in USA), Skylon – the UK, Avatar – India, Shenlong – China, MSS-1 – Russia.
Scenario B: In order to stablish reference service parameters for demonstration of the UHTCs to be developed in the frame of the project, the heating distribution environment and pressure in the nosecap of the re-entry vehicle X-38 have been analysed in addition to the requirements collected for scenario A. The trajectory of X-38 is similar to those of Space Shuttle, Buran, Hopper and Hermes.
Innovation brought in scenario B: Thanks to their extremely high melting point (above 3000°C) and their unique combination of thermo-physical and engineering properties, ultra-high temperature ceramics (UHTCs) and coatings on its basis are envisaged as promising candidates for application at very high temperatures. Specially, ZrB2 has several advantages over other metal-based borides and carbides. One critical issue in the production of ZrB2-based ceramics is the achievement of fully dense bodies/coatings, which is the base-line condition to achieve good thermo-mechanical properties. Owing to the strong covalent bonds featuring all UHTCs, processing temperatures above 2000°C and the application of very high pressures are required to densify these materials. However, the microstructure deriving from such extreme processing conditions are coarse, with trapped porosity and hence with poor oxidation and mechanical performances.
In view of these limitation, the addition of sintering additives has proved to be a suitable approach to decrease the sintering temperatures down to 1650°C and obtain better properties. The innovation brought by LIGHT-TPS consists on the investigation of new UHTC composites based on either the ZrB2-SiC or the ZrB2-MoSi2 systems, that will be suitable for application at temperatures between 1600 and 1800 ºC under the thermo-erosive influence of heterogeneous gas streams containing hard and liquid particles. The addition of sintering additives should allow the development of new UHTC mixtures suitable for the production of both UHTC-based bulk components and coatings.
Main achieved results in scenario B: On the one side, UHTC bulks from the ZrB2-SiC and ZrB2-MoSi2 systems possessing room temperature strength in the order of 500-730 MPa and the lowest specific weight gain upon exposure to oxidation at 1500°C were synthetized. It was concluded that little amount of SiO2-former, introduced as SiC or transition metal silicide, is beneficial to enable densification, to limit grains growth and to protect from oxidation. However, the amount of such SiO2-former has to be carefully controlled to limit the gas evolution in the subsurface scales and bubbles formation upon oxidation above 1600°C. The bending strength at 1400-1500°C of selected compositions remains almost constant compared to that at room temperature. Bulks containing WC developed at CNR even enabled to keep a strength over 700 MPa when tested at 1500°C in air. For the developed materials, the creep starting temperature ranges 1760 - 1930 °С and is max when B4C and WC are used as additives (1910 - 1930 °С). Depending on SiC amount and secondary phases, the CTE ranges from 4.8 to 7.9 10-6/C. Under thermo-cycling oxidation at 1650°C, none of the investigated materials showed oxide spallation and the best results were achieved when ZrB2 was sintered with solely MoSi2 or simultaneous addition of MoSi2 and CrB2.
After a careful assessment of collected results, following compositions were selected for the developments of coatings: ZrB2 + 3 vol% SiC + 5 vol% WC (outstanding HT mechanical properties in addition to the highest relative density and relative good oxidation resistance) and ZrB2 + 15 vol% MoSi2 (combination of good mechanical properties with outstanding oxidation resistance). Alternative atmospheric thermal spray depositions processes were investigated, leading to homogenous and dense UHTC single layers on the basis of ZrB2-3SiC-5WC, ZrB2-(15-20)MoSi2 and ZrB2-20SiC-(10-20)AlN. Accelerated oxidation tests have shown the potential of these UHTC coatings for the oxidation protection of non-oxide CMC substrates (C/C and C/SiC composites).
Potential impact and use in scenario B: Developed UHTCs in form of either bulk and coatings, could be implemented for the development of next generation of either: (1) TPSs for space vehicles flying at hypersonic speeds (i.e. greater than Mach 5) or (2) Nozzles of solid or hybrid aerospace rocket motors. Generally spoken, the newly developed UHTC coatings and bulks can be considered as a potential candidate where missions require a TPS system with heat loads above those state-of-the-art reusable TPSs can bear. Results achieved on flat CMC tiles could easily be extrapolated to more complex geometries (e..g. hemispheric, cylindrical, wedged, double tilted and even non-symmetric geometries) and with nearly no limitations in the size of the components. In this sense, in medium or long-term perspectives and for new missions where materials able to survive service temperatures above 1600 ºC will become of more interest, there is a good potential to bring results arising in LIGHT-TPS to this market. Concerning rocket nozzles, for projected service temperature exceeding 1600°C, the good chemical and thermal stability of the developed UHTC coatings and bulks makes them a good candidate for use in extreme environments, e.g. hypersonic flight and propulsion. Their application in nozzle extensions could lead to higher dimensional stability during firing in combustion chambers of high performance rockets for civil aerospace propulsion.
Public website: The public website has been maintained during the entire period starting from the launch at the beginning of the project (http://light-tps.eu/). Domains related to project meetings, publications and events have been constantly updated. All available key publications are downloadable from the website.
Dissemination: A promotion video of the project was developed. The information in the video provides a general insight into the project goals, major results, and scientific objectives. It is more suitable for professionals, as it includes specific references to materials, processes, target values of characteristics, etc. At the same time, it allows a person without a professional background to understand the general purpose of the project.
The content is structured in accordance with the general structure of the project work plan and embraces 3 areas:
- N-Cr and Nb based alloys and respective production technologies;
- Ultra-high temperature ceramic materials, production technologies and technologies for deposing ceramic coatings on various substrates;
- General design of the TPS elements in a structure, meeting the requirements of the target space mission.
Access to the promotional video can be obtained directly from the project website home page, on the bottom. The video is also available for streaming from Youtube: http://youtu.be/1dpowljWWco
Additionally, several dissemination activities have been undertaken by the consortium to present the project results in scientific events (mostly international conferences), 53 in total. 35 publications have been submitted to scientific journals (roughly half of them with open access). A workshop was organized by the consortium in the framework of the Space Conference at the Berlin International Aerospace Exhibition (ILA 2016). The workshop took place on June 01, 2016. The project promotional video and dissemination materials were distributed through the stand of YUZHNOJE. As a second joint dissemination activity from the consortium, a session was dedicated to the LIGHT-TPS project was collocated with the Symposium ZU: “Advanced Composite Materials: production, testing, applications” in the frame of the E-RMS FALL 2016 between 19-22th of September 2016 at the Warsaw University of Technology.
Exploitable project results and exploitation planning:
Following exploitable results (ER) have been achieved during the project:
ER1: New method for the thermal spray deposition of oxidation protective coatings on the basis of UHTCs (Owner: TECNALIA). IPR exploitation: Industrial secret.
ER2: Methods for preparing UHTC powders with desired diameter and inner cohesion for thermal spray deposition process (Owner: CNR). IPR exploitation: Industrial secret.
ER3: Non-oxide CMCs (C/C and C/C-SiC) coated with UHTCs for improved oxidation resistance (Owners: DLR, TECNALIA, CNR, IPMS). IPR exploitation: Industrial secret.
ER4: Preparation of ultra-refractory UHTC bulks with high strength above 1900°C (Owner: CNR). IPR exploitation: Industrial secret.
ER5: Alloys for cost-competitive protective TPS of reusable spacecrafts for prolonged operation at elevated temperatures (Owner: IPMS). IPR exploitation: Ukrainian patent № 108096 “Method for obtaining a heat-resistant alloy based on nichrome”; Ukrainian patent № 115259 “Method for obtaining a heat-resistant alloy”.
ER6: Method of rolling dispersed-hardened alloys (Owner: IPMS). IPR exploitation: Patented.
ER7: Equipment and test methods for sharp edges models of hypersonic aircraft (Owner: IPMS). IPR exploitation: None.
ER8: Novel method of diffusion welding three-layer honeycomb panels (Owner: IEW). IPR exploitation: Ukrainian patent for utility model, № 114804 Ukraine 2017, МПК В23К 20/00, B23K 20/16.
ER9: Novel method diffusion welding three-layer honeycomb panels (Owners: IEW, SRI). IPR exploitation: Ukrainian patent for utility model, № 113424 Ukraine, 2017, МПК В23К 20/14.
ER10: Novel design of three-layer panel and method of its diffusion welding (Owners: IEW, YUZHNOYE). IPR exploitation: Ukrainian patent application № 201701746 -23.02.2017-.
ER11: Novel method of the probabilistic risk assessment of the influence of the free space environment on the superlight-weight thermal protection system (TPS) (Owner: SRI). IPR exploitation: None.
ER12: System-theoretical approach to modeling and optimization of superlight-weight thermal protection system that based on the following models: synergetic, physical, and computational. (Owner: SRI). IPR exploitation: Company secret.
ER13: Novel method of TPS temperature properties modeling (Owner: SRI). IPR exploitation: Utility model.
ER14: Novel method of real time estimation of temperature distribution in a TPS using observer (Owners: SRI, IEW). IPR exploitation: In progress.
ER15: Novel method for calculating thermal fields in complex physical objects (Owner: SRI). IPR exploitation: Utility model.
ER16: Multilayer thermal protection system (Owner: YUZHNOYE). IPR exploitation: Ukrainian utility model 201709008.
ER17: Technology for high temperature soldering of elements during TPS assembly (i.e. joining of three-layered panels using the U-type element as well as for attachment of supports) (Owner: YUZHNOYE). IPR exploitation: Industrial secret.
ER18: Technology for light thermal insulation tiles manufacturing based on silica fibers, operating under 1200°С (Owner: YUZHNOYE). IPR exploitation: Industrial secret.
ER19: Special testing equipment and tooling for complex testing (Owner: YUZHNOYE). IPR exploitation: None.
List of Websites:
• The website is a kind of “business card” of the project contacting general and public information on:
• Project general mission and operational objectives
• Concise summary of the project activities
• Consortium composition
• Project meetings (short reports and public presentations)
• Contact details.
• News (permanently updating context-connected steam of project news, as well as other news relevant to the project objectives)
• Public downloads. The download section allows the access to public documents and other information resources developed by the project. Cross-linkage with other relevant information sources will be ensured. Examples of such public documents are project promotional materials, public scientific reports, open publications, information on patents, etc.
The same corporate design developed for the project was used for the website as well as for other public dissemination materials, for example the logo (see below)
Dr.-Ing. María Parco (Project Coordinator)
Head of the Thermal Spray Group
Industry and Transport Division
Parque Tecnológico de San Sebastián
Mikeletegi Pasealekua, 2
E-20009 Donostia-San Sebastián - Gipuzkoa (Spain)
T +34 946 430 850 (International calls)
F +34 946460900 (International)
Grant agreement ID: 607182
25 April 2014
1 September 2017
€ 2 741 034,20
€ 1 997 363
FUNDACION TECNALIA RESEARCH & INNOVATION
Deliverables not available
Grant agreement ID: 607182
25 April 2014
1 September 2017
€ 2 741 034,20
€ 1 997 363
FUNDACION TECNALIA RESEARCH & INNOVATION
Grant agreement ID: 607182
25 April 2014
1 September 2017
€ 2 741 034,20
€ 1 997 363
FUNDACION TECNALIA RESEARCH & INNOVATION