Optical characterization of alumina darkened with boron carbide inclusions for solar energy applications

Year: 2025

Authors: Failla S., Sani E., Sciti D.

Autors Affiliation: Natl Res Council Italy CNR, Inst Sci Technol & Sustainabil Ceram ISSMC, Via Granarolo 64, I-48018 Faenza, Italy; Natl Res Council Italy CNR, Natl Inst Opt INO, Largo E Fermi 6, I-50125 Florence, Italy.

Abstract: Dark colored Al2O3-B4C composites with 5-50 vol% B4C additions were consolidated by hot pressing. The optical properties were investigated to evaluate new potential applications as solar receivers in concentrating solar power. The thermal emittance was estimated from 400 to 1700 K, as well as the opto-thermal efficiency when these materials are used as solar radiation absorbers in concentrating solar plants, for three exemplifying values of solar concentration ratio C, representative of different solar plants architectures. Efficiency values for the composites was increased by four times with respect to conventional white Al2O3 (for instance, at 800 K and C = 3000 we found 0.88 versus 0.20, at 1300 K 0.83 vs. 0.19) and remarkably, were also higher that the most advanced solar absorber currently in use in solar plants, namely SiC (efficiency 0.84 or 0.81 in the mentioned cases). Complementarily, the effect of B4C on compaction behavior, microstructure and mechanical properties of the composites was also investigated. The addition of 50 vol% B4C significantly increased hardness and toughness compared to pure alumina, which could be of interest for structural applications, among others.

Journal/Review: SOLAR ENERGY MATERIALS AND SOLAR CELLS

Volume: 287      Pages from: 113619-1  to: 113619-9

More Information: This study was partially developed in the framework of the research activities carried out within the Project Network 4 Energy Sustainable Transition-NEST, Spoke 1, Project code PE0000021, funded under the National Recovery and Resilience Plan (NRRP), Mission 4, Component 2, Investment 1.3- Call for tender No. 1561 of October 11, 2022 of Ministero dell’Universita e della Ricerca (MUR) ; funded by the European Union-NextGenerationEU. The CNR-INO technician Mauro Pucci is acknowledged for technical support, as well as the CNR-INO administrative staff members Roberta Parenti, Antonella Alessi and Francesca Usala.
KeyWords: Concentrating solar power; Solar thermal absorbers; Alumina composites; Radiator cavities; Spectral emittance; Optical properties
DOI: 10.1016/j.solmat.2025.113619