In-situ study of crack initiation and propagation in a dual phase AlCoCrFeNi high entropy alloy

ABSTRACTThe application of relatively low resolution x-ray topography methods, typically ∿ 1 micrometer, is limited in studies which involve large scale dislocation networks. However, the ability to non-destructively image wide areas for “thick” specimens at high intensity with a tunable x-ray source makes the synchrotron an ideal probe for a range of problems previously inaccessible by other methods. Some examples will be discussed such as: (a) crack initiation and propagation in fatigued bicrystals, (b) real-time in situ plastic deformation studies in strain-annealed Mo crystals, and (c) strain distributions in vapor deposited and LPE thin films on Si and GaAs substrates.

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Low-cycle fatigue small crack initiation and propagation behaviour of cast magnesium alloys based on in-situ SEM observations

The Philosophical Magazine A Journal of Theoretical Experimental and Applied Physics ◽

10.1080/14786430500401070 ◽

2006 ◽

Vol 86 (11) ◽

pp. 1581-1596 ◽

Cited By ~ 27

Author(s):

X. S. Wang ◽

F. Liang ◽

J. H. Fan ◽

F. H. Zhang

Keyword(s):

Crack Initiation ◽

Magnesium Alloys ◽

Low Cycle Fatigue ◽

Small Crack ◽

Cycle Fatigue ◽

Crack Initiation And Propagation ◽

Initiation And Propagation ◽

Cast Magnesium Alloys ◽

Cast Magnesium

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Hydrogen enhanced cracking studies on Fe–3wt%Si single and bi-crystal microcantilevers

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2016.0410 ◽

2017 ◽

Vol 375 (2098) ◽

pp. 20160410 ◽

Cited By ~ 4

Author(s):

T. Hajilou ◽

Y. Deng ◽

N. Kheradmand ◽

A. Barnoush

Keyword(s):

Stress Concentration ◽

Crack Initiation ◽

The Other ◽

Bending Test ◽

Propagation Path ◽

Transgranular Fracture ◽

Post Mortem ◽

Crack Initiation And Propagation ◽

Initiation And Propagation

Hydrogen (H) enhanced cracking was studied in Fe–3wt%Si by means of in situ electrochemical microcantilever bending test. It was clearly shown that the presence of H causes hydrogen embrittlement (HE) by triggering crack initiation and propagation at the notch where stress concentration is existing. Additionally, the effect of carbon content and the presence of a grain boundary (GB) in the cantilever were studied. It was shown that in the presence of H the effect of carbon atom on pinning the dislocations is reduced. On the other hand, the presence of a GB, while the chemical composition of material kept constant, will promote the HE. Crack initiation and propagation occur in the presence of H, while the notch blunting was observed for both single and bi-crystalline beams bent in air. Post-mortem analysis of the crack propagation path showed that a transition from transgranular fracture to intragranular fracture mechanism is highly dependent on the position of the stress concentration relative to the GB. This article is part of the themed issue ‘The challenges of hydrogen and metals’.

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