Transforming Nanocrystals into Superhard Boron Carbide Nanostructures - Archive ouverte HAL
Journal Articles (Review Article) ACS Nano Year : 2024

Transforming Nanocrystals into Superhard Boron Carbide Nanostructures

Sylvie Le Floch
Gwenaëlle Rousse
David Portehault

Abstract

Boron carbide (B4+δC) possesses a large potential as structural material owing to its lightness, refractory character and outstanding mechanical properties. However, its large-scale industrialization is set back by its tendency to amorphize when subjected to an external stress. In the present work, we design a path towards nanostructured boron carbide with greatly enhanced hardness and resistance to amorphization. The reaction pathway consists of triggering an isomorphic transformation of covalent nanocrystals of Na1-xB5-xC1+x (x = 0.18) produced in molten salts. The resulting 10 nm B4.1C nanocrystals exhibit a four-fold decrease of size compared to previous works. Solid-state 11B and 13C NMR coupled to DFT reveal that the boron carbide nanocrystals are made of a complex mixture of atomic configurations, which are located at the covalent structural chains between B11C icosahedral building units. These nanocrystals are combined with a spark plasma sintering-derived method operated at high pressure. This yields full densification while maintaining particle size. The nanoscaled grains and high density of grain boundaries provide the resulting nanostructured bodies with significantly enhanced hardness and resistance to amorphization, thus delivering a superhard material.
Embargoed file
Embargoed file
0 5 21
Year Month Jours
Avant la publication
Saturday, April 26, 2025
Embargoed file
Saturday, April 26, 2025
Please log in to request access to the document

Dates and versions

hal-04754991 , version 1 (26-10-2024)

Identifiers

Cite

Fernando Igoa Saldaña, Thomas Gaudisson, Sylvie Le Floch, Benoît Baptiste, Ludovic Delbes, et al.. Transforming Nanocrystals into Superhard Boron Carbide Nanostructures. ACS Nano, 2024, ⟨10.1021/acsnano.4c08599⟩. ⟨hal-04754991⟩
0 View
0 Download

Altmetric

Share

More