TY - JOUR

T1 - Strain Field Around Individual Dislocations Controls Failure

AU - Gammer, Christoph

AU - Issa, Inas

AU - Minor, Andrew M.

AU - Ritchie, Robert O.

AU - Kiener, Daniel

N1 - Publisher Copyright: © 2024 The Authors. Small Methods published by Wiley-VCH GmbH.

PY - 2024/9/6

Y1 - 2024/9/6

N2 - Understanding material failure on a fundamental level is a key aspect in the design of robust structural materials, especially for metals and alloys capable to undergo plastic deformation. In the last decade, significant progress is made in quantifying the stresses associated with failure in both experiments and simulations. Nonetheless, the processes occurring on the most essential level of individual dislocations that govern semi-brittle and ductile fracture are still experimentally not accessible, limiting the failure prediction capabilities. Therefore, in the present work, a one-of-a-kind nanoscale fracture experiment is conducted on a single crystalline Cr bending beam in situ in the transmission electron microscope and for the first time quantify the transient strains around individual dislocations, as well as of the whole dislocation network during crack opening. The results reveal the importance of both pre-existing and newly emitted dislocations for crack-tip shielding via their intrinsic strain field and provide guidelines to design more damage tolerant materials.

AB - Understanding material failure on a fundamental level is a key aspect in the design of robust structural materials, especially for metals and alloys capable to undergo plastic deformation. In the last decade, significant progress is made in quantifying the stresses associated with failure in both experiments and simulations. Nonetheless, the processes occurring on the most essential level of individual dislocations that govern semi-brittle and ductile fracture are still experimentally not accessible, limiting the failure prediction capabilities. Therefore, in the present work, a one-of-a-kind nanoscale fracture experiment is conducted on a single crystalline Cr bending beam in situ in the transmission electron microscope and for the first time quantify the transient strains around individual dislocations, as well as of the whole dislocation network during crack opening. The results reveal the importance of both pre-existing and newly emitted dislocations for crack-tip shielding via their intrinsic strain field and provide guidelines to design more damage tolerant materials.

KW - 4D STEM strain mapping

KW - fracture experiments

KW - in situ TEM

KW - nanomechanical testing

UR - http://www.scopus.com/inward/record.url?scp=85203046628&partnerID=8YFLogxK

U2 - 10.1002/smtd.202400654

DO - 10.1002/smtd.202400654

M3 - Article

C2 - 39240006

AN - SCOPUS:85203046628

VL - 8.2024

JO - Small Methods

JF - Small Methods

SN - 2366-9608

IS - 12

M1 - 2400654

ER -