Nuclear Applications for Ultra‐High Temperature Ceramics and MAX Phases

Lee, William; Giorgi, Edoardo; Harrison, R. W.; Maı̂tre, Alexandre; Rapaud, Olivier

doi:10.1002/9781118700853.ch15

Cited by 32 publications

(19 citation statements)

References 44 publications

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“…Whereas most of the discussion abovedescribed aerospace applications, UHTCs are also candidates for use in applications such as advanced nuclear fission reactors, 84 high temperature electrodes for metal refining, 85 high power-density microelectronics, 86 concentrated solar power, 87 fusion energy systems, 88 and many others.In particular, nuclear applications have gained significant attention due to needs for accident-tolerant fuels andcladding, non-oxide fuel pellets, inert matrix fuels, waste separation, and moderators. 89 A growing number of possible applications should lead to additional research in this area. Some of the anticipated challenges arecost, minimizing impurities, producing dense materials, and estimating performance lifetime.…”

Section: Emerging Trendsmentioning

confidence: 99%

Ultra-high temperature ceramics: Materials for extreme environments

2017

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This paper identifies gaps in thepresent state of knowledge and describes emerging research directions for ultra-high temperature ceramics. Borides, carbides, and nitrides of early transition metals such as Zr, Hf, Nb, and Ta have the highest melting points of any known compounds, making them suitable for use in extreme environments.Studies of synthesis, processing, densification, thermal properties, mechanical behavior, and oxidation of ultra-high temperature ceramics have generated a substantial base of knowledge, but left unanswered questions. Emerging research directions include testing/characterization in extreme environments, composites, computational studies, and new materials.

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Section: Emerging Trendsmentioning

confidence: 99%

Ultra-high temperature ceramics: Materials for extreme environments

2017

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“…He concentration >> vacancy concentration). This may be of consequence for all potential HCP materials under consideration for use in first wall and divertor components such as titanium alloys [54] and MAX phases (where M = early transition metal, A = group A element and X = carbon or nitrogen) [4]. showing platelets predominantly orientated between {0001} planes but some face-on platelets and b) SADP of region in a) (corrected for rotation between micrograph and DP in TEM).…”

Section: Helium Platelet Characterisation At An Irradiation Temperatumentioning

confidence: 99%

“…This makes it a very promising candidate for use in the extreme environments of a nuclear reactor core where the material will be exposed to extreme temperatures and radiation damage from neutron bombardment. After the Fukushima disaster, SiCbased cladding was proposed as an accident tolerant coating to replace the current zircaloy cladding [3] and is also the leading candidate for use as the protective structural layer of the TRistructural ISOtropic (TRISO) coated fuel particles for the Very High Temperature (VHTR) Generation IV nuclear reactor [4]. It is also a candidate for use as a plasma facing material (PFM) in the first wall and divertor of the DEMOnstration fusion reactor [1].…”

Section: Introductionmentioning

confidence: 99%

Damage microstructure evolution of helium ion irradiated SiC under fusion relevant temperatures

Harrison

Ebert

Hinks

et al. 2018

Journal of the European Ceramic Society

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In-situ transmission electron microscopy (TEM) with ion irradiation has been used to study the damage microstructure evolution of He ion irradiated 4-H SiC at nuclear fusion relevant temperatures. The SiC samples were irradiated with 20 keV He ions at 25, 400, 800 and 1200°C to a dose of 5.0 displacements per atom (DPA). At 25°C, the material fully amorphises at 1.5 DPA and no He bubble nucleation occurs up to the doses studied. At 400 and 800°C, He bubble nucleation occurs and the material remains crystalline. Bubble nucleation occurs at 2.0 DPA at 400°C but occurs at only 0.5 DPA at 1200°C. This is attributed the He atoms de-trapping from vacancies and migrating interstitially to larger He-vacancy clusters at higher temperatures, leading to faster nucleation of observable He bubbles. Helium platelets form at an irradiation temperature of 1200°C at 0.5 DPA showing a preference for nucleation between the {0001} basal planes.

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“…The lower emissivity of ZrB 2 makes cooling through re-radiation less effective and the much higher thermal conductivity results in a higher backside temperature of the heat shield. The material lends itself to the transpiration cooling approach as the melting temperature is very high (3505 K) and the manufacturing allows for complex pore and channel arrangements [55,56]. The extremely fine port structure (in the order of 1 µm) also allows for a very even injection with no localised jets from fissures in the material [52].…”

Section: Resultsmentioning

confidence: 99%

Performance of Transpiration-Cooled Heat Shields for Reentry Vehicles

2020

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This paper presents results of a system study of transpiration cooled thermal protection systems for Earth re-entry. The cooling performance for sustained hypersonic flight and transient re-entry of a blunt cone geometry is assessed. A simplified numerical model is used to calculate the transient temperature of a transpiration cooled heat shield. The performance of transpiration cooling is assessed by calculating the overall required coolant mass for different steady state and transient flight scenarios. Spatially and temporally optimised mass injection is presented for various flight conditions. The majority of the injection is required on the spherical nose segment of the blunted cone. Carbon/Carbon composite ceramic and the ultra high temperature ceramic Zirconium diboride are considered as wall materials. Both materials require similar amounts of coolant injection. In continuous hypersonic cruise, transpiration cooling is highly effective for flight conditions with velocities below 8 km s −1 and altitudes above 40 km. For transient re-entry, transpiration cooling is most viable for trajectories of entry velocities below 8.5 km s −1 and ballistic coefficients below 2.1 kg m −2. Nomenclature A Area, m 2 C D Drag coefficient c p Specific heat capacity, J kg −1 K −1

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Nuclear Applications for Ultra‐High Temperature Ceramics and MAX Phases

Cited by 32 publications

References 44 publications

Ultra-high temperature ceramics: Materials for extreme environments

Ultra-high temperature ceramics: Materials for extreme environments

Damage microstructure evolution of helium ion irradiated SiC under fusion relevant temperatures

Performance of Transpiration-Cooled Heat Shields for Reentry Vehicles

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