Plastic flow between nanometer-spaced planar defects in nanostructured diamond and boron nitride

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989100%3A27640%2F20%3A10244891" target="_blank" >RIV/61989100:27640/20:10244891 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/61989100:27740/20:10244891

Výsledek na webu

<a href="https://journals.aps.org/prb/abstract/10.1103/PhysRevB.101.014104" target="_blank" >https://journals.aps.org/prb/abstract/10.1103/PhysRevB.101.014104</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevB.101.014104" target="_blank" >10.1103/PhysRevB.101.014104</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Plastic flow between nanometer-spaced planar defects in nanostructured diamond and boron nitride

Popis výsledku v původním jazyce

The fundamental mechanisms of strengthening/hardening and toughening that may be modified by various nanometer-spaced planar defects in the ultrahard nanostructured diamond and boron nitride (BN), e.g., nanotwins, stacking faults, and coherent heterophase interfaces, are still far from understood. In the present work, by means of first-principles approaches to derive ideal strength and Peierls stress, we performed a comprehensive investigation on the effect of the nanometer-spaced planar defects on the strength and plasticity of nanostructured diamond and BN under both uniform and localized deformations. A profound strengthening under uniform strain is revealed to be closely dependent on the spacing of planar defects, yet differing from the disappearing dependence under localized strain. It is further shown that the breakage and reconstruction of covalent bonds occurs only for very small spacing of planar defects under uniform deformations, being inconsistent with the average spacing found in the experimentally prepared nanotwinned diamond and BN, thus casting a doubt on the feasibility of the previously proposed strengthening mechanism. Under localized deformations, only the planar defects of twin in c-diamond or c-BN and coherent heterophase interface in c-/h-diamond or c-/w-BN are found to increase the barrier for the parallel slip of both 1/2(110) shuffle-set full dislocation and 1/6(112) glide-set partial dislocation, resulting in the strengthening of nanostructured diamond and BN, which agrees to the experimental observation. These findings not only yield a physical insight in strengthening/toughening nanostructured diamond and BN, but highlight the importance to understand the synergetic effect of length scale and interface between planar defects in designing superhard nanostructured materials.

Název v anglickém jazyce

Plastic flow between nanometer-spaced planar defects in nanostructured diamond and boron nitride

Popis výsledku anglicky

The fundamental mechanisms of strengthening/hardening and toughening that may be modified by various nanometer-spaced planar defects in the ultrahard nanostructured diamond and boron nitride (BN), e.g., nanotwins, stacking faults, and coherent heterophase interfaces, are still far from understood. In the present work, by means of first-principles approaches to derive ideal strength and Peierls stress, we performed a comprehensive investigation on the effect of the nanometer-spaced planar defects on the strength and plasticity of nanostructured diamond and BN under both uniform and localized deformations. A profound strengthening under uniform strain is revealed to be closely dependent on the spacing of planar defects, yet differing from the disappearing dependence under localized strain. It is further shown that the breakage and reconstruction of covalent bonds occurs only for very small spacing of planar defects under uniform deformations, being inconsistent with the average spacing found in the experimentally prepared nanotwinned diamond and BN, thus casting a doubt on the feasibility of the previously proposed strengthening mechanism. Under localized deformations, only the planar defects of twin in c-diamond or c-BN and coherent heterophase interface in c-/h-diamond or c-/w-BN are found to increase the barrier for the parallel slip of both 1/2(110) shuffle-set full dislocation and 1/6(112) glide-set partial dislocation, resulting in the strengthening of nanostructured diamond and BN, which agrees to the experimental observation. These findings not only yield a physical insight in strengthening/toughening nanostructured diamond and BN, but highlight the importance to understand the synergetic effect of length scale and interface between planar defects in designing superhard nanostructured 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

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2020

Kód důvěrnosti údajů

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

Název periodika

Physical review B

ISSN

2469-9950

e-ISSN

—

Svazek periodika

101

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

11

Strana od-do

—

Kód UT WoS článku

000507494000001

EID výsledku v databázi Scopus

2-s2.0-85078326827