Bor-nitridové nanotrubičky jako výztuž pro křehké matrice

Boron nitride nanotubes as a reinforcement for brittle matrices

článek v časopise ve Web of Science, Jimp

en

Cylindrical and bamboo-like boron nitride nanotubes (BNNTs) have been used to reinforce brittle amorphous borosilicate glass matrix materials prepared by spark plasma sintering. The mechanical properties, such as hardness, Youngs modulus, fracture toughness, and scratch resistance of the materials have been investigated. The fracture toughness of the composites showed an improvement of app. 30% compared to the pure amorphous glass. BNNTs pull-out, crack bridging, stretching, and crack deflection toughening mechanisms were observed in the reinforced glass matrix composites. Extensive pull-out of the BNNTs (>400 nm) was observed in the form of the telescopic sword-in-sheath mechanism, resulting in poor energy dissipation due to the weak Van der Waals force between the inner walls of the BNNTs. The scratch resistance was significantly improved (app.26%) after the addition of the BNNTs, and the results correspond well with the brittleness index of the materials.

Nanotrubičky z nitridu bóru s valcovou a bambusovou morfologií (BNNTs) byly použity ke zhouževnatění křehké amorfní borosilikátové skelné matrice za použití "spark plasma sintering" technologie. Na připravených kompozitech byly dále zkoumány mechanické vlastnosti, jako je tvrdost, modul pružnosti, lomová houževnatost a otěruvzdornost. Lomová houževnatost kompozitu ukázala zlepšení ve srovnání s čistým amorfním sklem a to o 30%. BNNTs vedly k projevům přemostění trhliny, pull-out zhouževnaťujícho mechanismu. Rovněž bylo pozorováno rozsáhlé vytažení z BNNTs (> 400 nm) v podobě teleskopického " sword-in-sheath" umožněného slabými Van der Waalsovými sílami mezi vnitřními stěnami BNNTs. Odolnost proti vrypu se významně zvýšila (přibližně o 26%) a výsledky dobře korespondují s indexem křehkosti.

Cylindrical and bamboo-like boron nitride nanotubes (BNNTs) have been used to reinforce brittle amorphous borosilicate glass matrix materials prepared by spark plasma sintering. The mechanical properties, such as hardness, Youngs modulus, fracture toughness, and scratch resistance of the materials have been investigated. The fracture toughness of the composites showed an improvement of app. 30% compared to the pure amorphous glass. BNNTs pull-out, crack bridging, stretching, and crack deflection toughening mechanisms were observed in the reinforced glass matrix composites. Extensive pull-out of the BNNTs (>400 nm) was observed in the form of the telescopic sword-in-sheath mechanism, resulting in poor energy dissipation due to the weak Van der Waals force between the inner walls of the BNNTs. The scratch resistance was significantly improved (app.26%) after the addition of the BNNTs, and the results correspond well with the brittleness index of the materials.

nanotrubičky nitridu bóru; bambusová morfologie; válcové nanotrubičky; borosilikátové sklo; lomová houževnatost; zhouževnatění

boron nitrice nanotubes; bamboo like; cylindrical nanotubes; borosilicate glass; fracture toughnes; toughening

2014

01.05.2014

Elsevier

0955-2219

34

14

3339–3349

11