Ultra-high temperature ceramic matrix composites (UHTCMC) or Ultra-high Temperature Ceramic Composites (UHTCC) are a class of refractory

ceramic matrix composite In materials science, ceramic matrix composites (CMCs) are a subgroup of composite materials and a subgroup of ceramics. They consist of ceramic fibers embedded in a ceramic matrix. The fibers and the matrix both can consist of any ceramic mate ...

s ( CMCs), which aspires to overcome the limits associated with currently used CMCs (C/C and C/SiC) in aerospace field as thermal protection systems (TPS) and rocket nozzles. Carbon fiber reinforced

carbon Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—its atom making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon makes ...

matrix ( C/C) can be used up to 3000 °C because carbon is the element with the highest melting point however C/C are ablative materials which dissipate energy consuming themselves. Carbon fiber reinforced silicon carbide matrix composites ( C/SiC) and Silicon carbide fiber reinforced silicon carbide matrix composites ( SiC/SiC) are considered reusable materials because silicon carbide is a hard material with a low erosion and it forms a silica glass layer during oxidation which prevents further oxidation of inner material. Unfortunately above a certain temperature (it depends on environmental conditions of oxygen partial pressure) starts the active oxidation of

silicon carbide Silicon carbide (SiC), also known as carborundum (), is a hard chemical compound containing silicon and carbon. A semiconductor, it occurs in nature as the extremely rare mineral moissanite, but has been mass-produced as a powder and crystal ...

matrix to gaseous

silicon monoxide Silicon monoxide is the chemical compound with the formula SiO where silicon is present in the oxidation state +2. In the vapour phase, it is a diatomic molecule. It has been detected in stellar objects and has been described as the most common ...

(

SiO Sio may refer to: Places * Sió, an artificial channel in Hungary * Siø, a small Danish island in the South Funen Archipelago * Sio, Burkina Faso, a village in Burkina Faso * Sio, Mali, a commune in Mali * Sio, Papua New Guinea, a town in ...

_(g)), consequently loss of protection from further oxidation, which leads the material to an uncontrolled and fast erosion. For this reason C/SiC and SiC/SiC are used in the range of temperature between 1200° - 1400 °C. On the one hand CMCs are lightweight materials with high strength-to-weight ratio even at high temperature, high thermal shock resistance and toughness but suffer of erosion during service. On the other side bulk ceramics made of UHTCs (e.g. ZrB₂, HfB₂, or their composites) are hard materials which show low erosion even above 2000 °C but are heavy and suffer of catastrophic fracture and low thermal shock resistance compared to CMCs. Failure is easily under mechanical or thermo-mechanical loads because of cracks initiated by small defects or scratches. The possibility to obtain reusable components for aerospace field based on UHTC matrix into fiber reinforced composites is still under investigation. The European Commission funded a research project, C3HARME, under the NMP-19-2015 call of Framework Programmes for Research and Technological Development in 2016 (still ongoing) for the design, development, production and testing of a new class of ultra-refractory ceramic matrix composites reinforced with silicon carbide fibers and Carbon fibers suitable for applications in severe aerospace environments as possible near-zero ablation thermal protection system (TPS) materials (e.g.

heat shield In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. A thermodynamic system does not ''contain'' heat. Nevertheless, the term is al ...

) and for propulsion (e.g. rocket nozzle). The demand for reusable advanced materials with temperature capability over 2000 °C has been growing. Recently carbon fiber reinforced zirconium boride-based composites obtained by slurry infiltration (SI) and sintering has been investigated.

Breakthroughs in research

The

European Commission The European Commission (EC) is the executive of the European Union (EU). It operates as a cabinet government, with 27 members of the Commission (informally known as "Commissioners") headed by a President. It includes an administrative body ...

funded a research project, C3HARME, under the NMP-19-2015 call of

Framework Programmes for Research and Technological Development The Framework Programmes for Research and Technological Development, also called Framework Programmes or abbreviated FP1 to FP9, are funding programmes created by the European Union/European Commission to support and foster research in the Europe ...

in 2016 (still ongoing) for the design, development, production and testing of a new class of ultra-refractory ceramic matrix composites reinforced with

silicon carbide fibers Silicon carbide fibers are fibers ranging from 5 to 150 micrometres in diameter and composed primarily of silicon carbide molecules. Depending on manufacturing process, they may have some excess silicon or carbon, or have a small amount of oxyg ...

and

Carbon fibers Carbon fibers or carbon fibres (alternatively CF, graphite fiber or graphite fibre) are fibers about in diameter and composed mostly of carbon atoms. Carbon fibers have several advantages: high stiffness, high tensile strength, high stren ...

suitable for applications in severe aerospace environments.

References

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