Compositional dependence of optical properties of zirconium, hafnium and tantalum carbides for solar absorber applications

Ultra-high temperature ceramics: Materials for extreme environments

“…81,82 Rather than conventional experimental approaches, the search for new UHTCs is likely to be driven by computational means and will likely require novel approaches such as exploring entropy-stabilization 83 Several new applications will also motivate future research on UHTCs. 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.…”

Processing, Mechanical and Optical Properties of Additive-Free ZrC Ceramics Prepared by Spark Plasma Sintering

“…For the sake of comparison of the sample tackled in the present work with analogous previously investigated systems, i.e. , sintering aid-doped ZrC [ 43 ] and fully dense monolithic ZrB 2 obtained by SHS/SPS [ 44 ]. Parameters appearing in Equations (2) and (3) have been calculated by considering integration bounds λ min = 0.3 μm, λ max = 2.3 μm, λ 1 = 0.3 μm, λ 2 = 15.0 μm and temperatures of 1200 K and 1400 K. Correspondingly, α = 0.51, ε (1200 K) = 0.21, and ε (1400 K) = 0.24 are obtained for the case of the ZrC sample produced in this work, which leads to α / ε (1200 K) = 2.4, and α / ε (1400 K) = 2.1.…”

“…Parameters appearing in Equations (2) and (3) have been calculated by considering integration bounds λ min = 0.3 μm, λ max = 2.3 μm, λ 1 = 0.3 μm, λ 2 = 15.0 μm and temperatures of 1200 K and 1400 K. Correspondingly, α = 0.51, ε (1200 K) = 0.21, and ε (1400 K) = 0.24 are obtained for the case of the ZrC sample produced in this work, which leads to α / ε (1200 K) = 2.4, and α / ε (1400 K) = 2.1. Based on these results, it can be stated that the latter product is slightly less absorptive and emissive with respect to MoSi 2 -containing ZrC samples ( α = 0.55–0.56 and ε (1200 K) = 0.23–0.27), while spectral selectivity (2.4–2.1) is similar [ 43 ]. In addition, when the comparison is extended to the bulk additive-free ZrB 2 material recently processed following the same SHS/SPS route [ 40 ], it is found that the ZrC product appears slightly more absorptive and emissive, i.e.…”

An overview of ultra-refractory ceramics for thermodynamic solar energy generation at high temperature

“…The increasing interest in these materials is due to their unique combination of properties, including the highest melting points of any group of materials, >3000°C, elevate strength at extreme temperature, like 600-800 MPa at 1500-2100°C [11], high thermal conductivity, 80-110 W/mK up to 2000°C [12] and chemical stability. Recently, it has been found that most of these compounds also have the characteristic of being intrinsic solar selective materials [13][14][15][16][17][18][19], but the understanding of the optical properties of these materials is still very scanty, especially at high temperature. UHTCs have thus the potential to be suited for application in high temperature solar receivers, once their basic properties have been properly investigated and correlated to the bulk and surface characteristics.…”