Deformation and failure of the CrCoNi medium-entropy alloy subjected to extreme shock loading

Zhao, Shiteng; Xiao, Liang; Cao, Fuhua; Yu, Qin; Zhang, Ruopeng; Dai, Lan-Hong; Ruestes, Carlos J.; Ritchie, Robert O.; Minor, Andrew M.

doi:10.1126/sciadv.adf8602

Cited by 37 publications

(2 citation statements)

References 94 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Effectively, we are sampling small volumes out of a larger volume, and so spatial heterogeneities on scales larger than the laser-shock sample sizes have to be viewed from a statistical sampling perspective. If the relevant defect/feature distributions in the material are sufficiently small, the sampling statistics are less of an issue ( 17 , 19 , 63 , 66 , 67 ). We also note some limitations with the PDV approach used in spall experiments.…”

Section: Methodsmentioning

confidence: 99%

High-throughput quantification of quasistatic, dynamic and spall strength of materials across 10 orders of strain rates

Eswarappa Prameela,

Walker,

DiMarco

et al. 2024

PNAS Nexus

View full text Add to dashboard Cite

The response of metals and their microstructures under extreme dynamic conditions can be markedly different from that under quasistatic conditions. Traditionally, high strain rates and shock stresses are achieved using cumbersome and expensive methods such as the Kolsky bar or large spall experiments. These methods are low throughput and do not facilitate high-fidelity microstructure-property linkages. In this work, we combine two powerful small-scale testing methods, custom nanoindentation, and laser-driven micro-flyer shock, to measure the dynamic and spall strength of metals. The nanoindentation system is configured to test samples from quasistatic to dynamic strain rate regimes. The laser-driven micro-flyer shock system can test samples through impact loading, triggering spall failure. The model material used for testing is Magnesium alloys, which are lightweight, possess high-specific strengths, and have historically been challenging to design and strengthen due to their mechanical anisotropy. We adopt two distinct microstructures, solutionized (no precipitates) and peak-aged (with precipitates) to demonstrate interesting upticks in strain rate sensitivity and evolution of dynamic strength. At high shock loading rates, we unravel an interesting paradigm where the spall strength versus strain rate of these materials converges, but the failure mechanisms are markedly different. Peak aging, considered to be a standard method to strengthen metallic alloys, causes catastrophic failure, faring much worse than solutionized alloys. Our high throughput testing framework not only quantifies strength but also teases out unexplored failure mechanisms at extreme strain rates, providing valuable insights for the rapid design and improvement of materials for extreme environments.

show abstract

Section: Methodsmentioning

confidence: 99%

High-throughput quantification of quasistatic, dynamic and spall strength of materials across 10 orders of strain rates

Eswarappa Prameela,

Walker,

DiMarco

et al. 2024

PNAS Nexus

View full text Add to dashboard Cite

show abstract

“…Plastic deformations in the early stages are dominated by dissociation and planar slipping of dislocations. Although they tend to be activated at high strain levels , or extreme loading conditions, − deformation twinning and FCC-hexagonal close-packed (HCP) martensitic transformation are responsible for the remarkable work-hardening rate at the later deformation stages. ,,− …”

mentioning

confidence: 99%

Atomic-Scale In Situ Observations of Reversible Phase Transformation Assisted Twinning in a CrCoNi Medium-Entropy Alloy

Chu,

Zhang,

Chen

et al. 2024

Nano Lett.

View full text Add to dashboard Cite

Twinning is an important deformation mode of face-centered-cubic (FCC) medium-and high-entropy alloys, especially under extreme loading conditions. However, the twinning mechanism in these alloys that have a low or even negative stacking fault energy remains debated. Here, we report atomic-scale in situ observations of the deformation process of a prototypical CrCoNi medium-entropy alloy under tension. We found that the parent FCC phase first transforms into a hexagonal close-packed (HCP) phase through Shockley partial dislocations slipping on the alternate {111} planes. Subsequently, the HCP phase rapidly changes to an FCC twin band. Such reversible phase transformation assisted twinning is greatly promoted by external tensile loads, as elucidated by geometric phase analysis. These results indicate the previously underestimated role of the metastable HCP phase in nanotwin nucleation and early plastic deformations of CrCoNi alloys and shed light on microstructure regulation of medium-entropy alloys with enhanced mechanical properties.

show abstract

Molecular Dynamics Investigation of Shock-Induced Deformation Behavior and Failure Mechanism in Metallic Materials

Zhu,

Gong,

2024

Arch Computat Methods Eng

View full text Add to dashboard Cite

Deformation and failure of the CrCoNi medium-entropy alloy subjected to extreme shock loading

Cited by 37 publications

References 94 publications

High-throughput quantification of quasistatic, dynamic and spall strength of materials across 10 orders of strain rates

High-throughput quantification of quasistatic, dynamic and spall strength of materials across 10 orders of strain rates

Atomic-Scale In Situ Observations of Reversible Phase Transformation Assisted Twinning in a CrCoNi Medium-Entropy Alloy

Molecular Dynamics Investigation of Shock-Induced Deformation Behavior and Failure Mechanism in Metallic Materials

Contact Info

Product

Resources

About