Ultra-high temperature ceramics: Aspiration to overcome challenges in thermal protection systems

Improved interest in ultra-high-temperature ceramics (UHTCs) is being animating the scientific community. This emerging attention is driven by the demand of developing re-usable hot structures as thermal protection systems of aerospace vehicles, able to re-enter in planetary atmospheres at relatively high speed (order of 8-11 Km/s). In contrast to traditional blunt capsules or Shuttle-like vehicles, characterised by poor gliding capabilities and complex thermal protection systems, the future use of UHTCs opens new horizons for the development of spaceplanes with slender fuselage noses and sharp wing leading edges. Advanced aerodynamic configurations reduce the vehicles drag, enhance the vehicles performances, due to a larger manoeuvrability resulting in larger down range, cross range and abort windows, and reduce electromagnetic interferences and communications black-out. Analysis has shown that materials with temperature capability approaching 2000°C and above will be required for these space vehicles, but the state of the art Reinforced Carbon-Carbon (RCC) material, currently used on the Space Shuttle, have maximum use temperatures of approximately 1650°C. The articles collected in this issue provide state-of-art scientific advancements on the subject with particular attention to the potential technological applications. The papers specifically deal with research studies on monolithic ceramic materials, composed primarily of Zirconium and Hafnium Diborides with different additives. The activities are carried out at materials level, with furnace or arc-jet testing, or include developments of UHTC-based hot structures at sub-component level. In the latter case, ultra-high temperature ceramic prototype structures have been developed and tested with embedded structural health monitoring systems. I want to thank all the article contributors for their manuscripts. I hope they will be useful for future basic and applied researches on the subject.

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AERO-THERMO-DYNAMIC STUDY OF ULTRA-HIGH- TEMPERATURE CERAMIC COMPOSITES FOR THERMAL PROTECTION SYSTEMS AND ROCKET NOZZLES

10.12783/asc36/35774 ◽

2021 ◽

Author(s):

STEFANO MUNGIGUERRA ◽

ANSELMO CECERE ◽

RAFFAELE SAVINO

Keyword(s):

High Temperature ◽

Thermal Protection ◽

Ceramic Composites ◽

Thermal Protection Systems ◽

Research Activities ◽

Ablation Resistance ◽

Protection Systems ◽

Project Objectives ◽

Ultra High Temperature

The most extreme aero-thermo-dynamic conditions encountered in aerospace applications include those of atmospheric re-entry, characterized by hypersonic Mach numbers, high temperatures and a chemically reacting environment, and of rocket propulsion, in which a combusting, high-pressure, supersonic flow can severely attack the surfaces of the motor internal components (particularly nozzle throats), leading to thermo-chemical erosion and consequent thrust decrease. For these applications, Ultra-High-Temperature Ceramics (UHTC), namely transition metal borides and carbides, are regarded as promising candidates, due to their excellent high-temperature properties, including oxidation and ablation resistance, which are boosted by the introduction of secondary phases, such as silicon carbide and carbon fibers reinforcement (in the so-called Ultra-High- Temperature Ceramic Matrix Composites, UHTCMC). The recent European H2020 C3HARME research project was devoted to development and characterization of new-class UHTCMCs for near-zero ablation thermal protection systems for re-entry vehicles and near-zero erosion rocket nozzles. Within the frame of the project and in collaboration with several research institutions and private companies, research activities at the University of Naples “Federico II” (UNINA) focused on requirements definition, prototypes design and test conditions identification, with the aim to increase the Technology Readiness Level (TRL) of UHTCMC up to 6. Experimental tests were performed with two facilities: an arc-jet plasma wind tunnel, where small specimens were characterized in a relevant atmospheric re-entry environment (Fig.1a), and a lab-scale hybrid rocket engine, where material testing was performed with different setups, up to complete nozzle tests, in conditions representative of real propulsive applications (Fig.1b). The characterization of the aero-thermo-chemical response and ablation resistance of different UHTCMC formulations was supported by numerical computations of fluiddynamic flowfields and materials thermal behavior. The UNINA activities provided a large database supporting the achievement of the project objectives, with development and testing of full-scale TPS assemblies and a large-size solid rocket nozzle.

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INTRODUCTION TO C3HARME PROJECT

10.12783/asc36/35777 ◽

2021 ◽

Author(s):

LUCA ZOLI ◽

DILETTA SCITI

Keyword(s):

High Temperature ◽

High Speed ◽

Thermal Protection ◽

Weight Ratio ◽

Ceramic Matrix Composites ◽

Ceramic Matrix ◽

Matrix Composites ◽

Thermal Protection Systems ◽

Protection Systems ◽

Ultra High Temperature

High-speed aviation brings many challenges, one being the materials used ensure the aircraft and rockets travelling at hypersonic speed arrive at their destination safely. Control surfaces and thermal protection systems for vehicles flying at Mach 5 or above must withstand extremely hot temperatures and intense mechanical vibrations at launch, during cruising and re-entry into the Earth’s atmosphere. UHTCMCs (Ultra-High Temperature Ceramic Matrix Composites) belong to a new subclass of ceramic matrix composites (CMCs) with superior properties in terms of structural and chemical stability at elevated temperature and erosion/ablation resistance keeping excellent strength-to-weight ratio, thermal shock resistance and adequate damage tolerance. They are the latest potential candidates for thermal protection systems (TPSs), able to outperform bulk ultra-high temperature ceramics (UHTCs). C3HARME is a 4-years EU funded program involving 12 European partners from 6 countries focused on the design, fabrication and testing of UHTCMCs for nearzero erosion nozzles and near-zero ablation TPS tiles. C3harme will look at different technologies coming from the science of bulk ceramics and CMCs and combine them to find out new approaches for their manufacturing. Novel theoretical models and testing methodologies are necessary to characterize properly these materials. This talk will summarize some of the findings and advances of the program, with special emphasis on the innovative approaches that we have implemented.

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Trends in the development of flexible thermal protection systems for modern aircraft

Perspektivnye Materialy ◽

10.30791/1028-978x-2020-6-10-21 ◽

2020 ◽

pp. 10-21

Author(s):

V. G. Babashov ◽

◽

N. M. Varrik ◽

Keyword(s):

High Temperature ◽

Thermal Protection ◽

Heat Removal ◽

Operating Conditions ◽

Passive Protection ◽

Thermal Protection Systems ◽

Heat Protection ◽

Protection Systems ◽

Protected Surface ◽

Flexible Panels

The emergence of new types of space and aviation technology necessitates the development of new types of thermal protection systems capable of operating at high temperature and long operating times. There are several types of thermal protection systems for different operating conditions: active thermal protection systems using forced supply of coolant to the protected surface, passive thermal protection systems using materials with low thermal conductivity without additional heat removal, high-temperature systems, which are simultaneously elements of the bearing structure and provide thermal protection, ablation materials. Heat protection systems in the form of rigid tiles and flexible panels, felt and mats are most common kind of heat protecting systems. This article examines the trends of development of flexible reusable heat protection systems intended for passive protection of aircraft structural structures from overheating.

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ZIRCONIA FIBERS AS A COMPONENT OF HIGH TEMPERATURE THERMAL INSULATION (review)

Proceedings of VIAM ◽

10.18577/2307-6046-2021-0-10-79-86 ◽

2021 ◽

pp. 79-86

Author(s):

V.G. Babashov ◽

◽

N.M. Varrik ◽

Keyword(s):

High Temperature ◽

Thermal Insulation ◽

Zirconium Oxide ◽

Thermal Protection ◽

Sol Gel ◽

Precursor Solution ◽

Technical Literature ◽

Thermal Protection Systems ◽

Insulation Materials ◽

Protection Systems

Based on the analysis of recent publications of scientific and technical literature, data on the production of zirconium oxide fibers used for the manufacture of high-temperature thermal insulation materials are presented. Information is provided on various methods of obtaining zirconium oxide fibers (methods of impregnation of the template and molding of the mixture, sol-gel method of spinning a fiber-forming precursor solution), as well as on the technique of fiber molding (manual pulling, dry and wet spinning, blowing and electrospinning). The use of such fibers for the production of thermal insulation materials (felts, cords and blocks) instead of currently existing materials made of aluminum oxide-based fibers can significantly increase the operating temperatures of the thermal protection systems.

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Processing Methods for Ultra High Temperature Ceramics

MAX Phases and Ultra-High Temperature Ceramics for Extreme Environments ◽

10.4018/978-1-4666-4066-5.ch006 ◽

2013 ◽

pp. 180-202 ◽

Cited By ~ 5

Author(s):

J.K. Sonber ◽

T.S.R. Ch. Murthy ◽

C. Subramanian ◽

R.C. Hubli ◽

A.K. Suri

Keyword(s):

High Temperature ◽

Elevated Temperatures ◽

Thermal Protection ◽

Leading Edge ◽

Powder Synthesis ◽

Ultra High Temperature Ceramics ◽

Sharp Edges ◽

The Stability ◽

Intense Heat ◽

Ultra High Temperature

Ultra-high-temperature ceramics (UHTCs) are a group of materials that can withstand ultra high temperatures (1600-3000 oC) which will be encountered by future hypersonic re-entry vehicles. Future re-entry vehicles will have sharp edges to improve flight performance. The sharp leading edges result in higher surface temperature than that of the actual blunt edged vehicles that could not be withstood by the conventional thermal protection system materials. To withstand the intense heat generated when these vehicles dip in and out of the upper atmosphere, UHTC materials are needed. UHTC materials are composed of borides of early transition metals. From the larger list of borides, ZrB2 and HfB2 have received the most attention as potential candidates for leading edge materials because their oxidation resistance is superior to that of other borides due to the stability of the ZrO2 and HfO2 scales that form on these materials at elevated temperatures in oxidizing environments. Processing of these materials is very difficult as these materials are very refractory in nature. In this chapter, processes available for powder synthesis, fabrication of dense bodies, and coating processes is discussed.

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