Sintering, Mechanical and Optical Properties of TiB2 Composites with and without High-Energy Milling

Year: 2023

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

Autors Affiliation: Natl Res Council Italy, Inst Sci Technol & Sustainabil Ceram, Via Granarolo 64, I-48018 Faenza, Italy; Univ Parma, Dept Chem Life Sci & Environm Sustainabil, Parco Area Sci 11-A, I-43124 Parma, Italy; Natl Res Council Italy, Natl Inst Opt, Largo E Fermi 6, I-50125 Florence, Italy.

Abstract: TiB2 is a promising material for several fields including impact-resistant armor, wear-resistant coatings, cutting tools and crucibles given its physical, mechanical and chemical properties, especially due to the combination of high hardness and exceptional wear resistance. It is however very difficult to sinter below 2000degree celsius, even under mechanical pressure; moreover, the low fracture toughness limits the applicability of the ceramic material. By using sintering additives, it is possible to improve the sintering process and increase the mechanical properties since the additives react with oxidized layers and form secondary phases. In this study, different preparation methods and various combinations of additives (B4C, Si(3)N4 and MoSi2) via hot pressing sintering have been explored. Through the synergy between optimized process and tailored composition, an almost fully dense material was obtained at 1700degree celsius with hardness of 24.4 +/- 0.2 GPa and fracture toughness of 5.4 +/- 0.2 MPa m(1/2). However, the highest hardness (24.5 +/- 0.2 GPa) and density values were obtained for only the high-energy-milled sample with WC-Co media, featuring a core-shell grain structure. Finally, optical properties for selected samples were measured, identifying the high-energy-milled TiB2 as the sample with the highest spectral selectivity alpha/epsilon and solar absorptance.

Journal/Review: NANOMATERIALS

Volume: 13 (19)      Pages from: 2683-1  to: 2683-18

More Information: Industrie Bitossi S.p.A and CNR are acknowledged for supporting the PhD of S. Taraborelli. ES would like to thank the CNR-INO technicians M. Pucci and M. D’Uva for technical assistance.
KeyWords: TiB2; high-energy milling; hardness; armor materials; optical properties; solar absorbers
DOI: 10.3390/nano13192683