Plasticity Mechanisms in Nanostructured Cubic Boron Nitride: Internal Defects and Amorphous Layers

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989100%3A27740%2F25%3A10258674" target="_blank" >RIV/61989100:27740/25:10258674 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11320/25:10503686

Výsledek na webu

<a href="https://pubs.acs.org/doi/10.1021/acsami.5c10992" target="_blank" >https://pubs.acs.org/doi/10.1021/acsami.5c10992</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acsami.5c10992" target="_blank" >10.1021/acsami.5c10992</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Plasticity Mechanisms in Nanostructured Cubic Boron Nitride: Internal Defects and Amorphous Layers

Popis výsledku v původním jazyce

Nanostructured cubic boron nitride (NS-cBN) has attracted significant attention due to its high hardness and excellent thermal stability, yet a systematic strategy to balance strength and toughness through atomically structural design remains elusive. Here, we integrate plasticity theory with large-scale atomistic simulations to elucidate the size-dependent roles of internal defects, i.e., twin boundaries (TBs), stacking faults (SFs), and dislocation networks, and amorphous interfacial layers (AILs) in NS-cBN. In samples containing TBs and SFs, we demonstrate uniquely that the competition between hard slip modes (e.g., dislocation penetration) and soft slip modes (e.g., sliding parallel to defects), together with grain-boundary sliding, governs the scaling of strength and crack-initiation strain. Specially, a cross-slip of 1/2[110] screw dislocations emerges as the dominant plastic mechanism penetrating planar defects, while high-density SFs leverage stress concentration to activate the destacking fault mechanism, thereby improving crack-initiation strain with high strength. Introducing pre-existing dislocation networks shifts deformation from a grain-boundary-dominated to a dislocation-dominated regime, achieving a 76% increase in failure strain (up to 15% compressive strain) and a metal-like plastic plateau at a dislocation density of 0.115 nm-2. Moreover, a 0.5 nm-thick AIL is found to simultaneously enhance strength and toughness by homogenizing stress, suppressing shear bands, and crack-initiation; further thickening of the AIL leads to softening, while increasing its density or bond strength amplifies its reinforcing effect. By synergistically tailoring internal defects and AILs, we achieve NS-cBN materials that combine high strength with high toughness, and thereby, we establish general design principles to guide the development of next-generation superhard materials.

Název v anglickém jazyce

Plasticity Mechanisms in Nanostructured Cubic Boron Nitride: Internal Defects and Amorphous Layers

Popis výsledku anglicky

Nanostructured cubic boron nitride (NS-cBN) has attracted significant attention due to its high hardness and excellent thermal stability, yet a systematic strategy to balance strength and toughness through atomically structural design remains elusive. Here, we integrate plasticity theory with large-scale atomistic simulations to elucidate the size-dependent roles of internal defects, i.e., twin boundaries (TBs), stacking faults (SFs), and dislocation networks, and amorphous interfacial layers (AILs) in NS-cBN. In samples containing TBs and SFs, we demonstrate uniquely that the competition between hard slip modes (e.g., dislocation penetration) and soft slip modes (e.g., sliding parallel to defects), together with grain-boundary sliding, governs the scaling of strength and crack-initiation strain. Specially, a cross-slip of 1/2[110] screw dislocations emerges as the dominant plastic mechanism penetrating planar defects, while high-density SFs leverage stress concentration to activate the destacking fault mechanism, thereby improving crack-initiation strain with high strength. Introducing pre-existing dislocation networks shifts deformation from a grain-boundary-dominated to a dislocation-dominated regime, achieving a 76% increase in failure strain (up to 15% compressive strain) and a metal-like plastic plateau at a dislocation density of 0.115 nm-2. Moreover, a 0.5 nm-thick AIL is found to simultaneously enhance strength and toughness by homogenizing stress, suppressing shear bands, and crack-initiation; further thickening of the AIL leads to softening, while increasing its density or bond strength amplifies its reinforcing effect. By synergistically tailoring internal defects and AILs, we achieve NS-cBN materials that combine high strength with high toughness, and thereby, we establish general design principles to guide the development of next-generation superhard materials.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

—

Návaznosti

—

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

ACS applied materials &amp; interfaces

ISSN

1944-8244

e-ISSN

1944-8252

Svazek periodika

17

Číslo periodika v rámci svazku

37

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

14

Strana od-do

52854-52867

Kód UT WoS článku

001567355600001

EID výsledku v databázi Scopus

2-s2.0-105016689622