Super-elastic ferroelectric single-crystal membrane with continuous electric dipole rotation

Science ◽  
2019 ◽  
Vol 366 (6464) ◽  
pp. 475-479 ◽  
Author(s):  
Guohua Dong ◽  
Suzhi Li ◽  
Mouteng Yao ◽  
Ziyao Zhou ◽  
Yong-Qiang Zhang ◽  
...  
Keyword(s):  
Energy Landscape ◽  
Domain Engineering ◽  
Bending Test ◽  
Dynamic Evolution ◽  
Brittle Deformation ◽  
Continuous Transition ◽  
Flexible Sensors ◽  
Mismatch Stress ◽  
Ferroelectric Single Crystal

Ferroelectrics are usually inflexible oxides that undergo brittle deformation. We synthesized freestanding single-crystalline ferroelectric barium titanate (BaTiO3) membranes with a damage-free lifting-off process. Our BaTiO3 membranes can undergo a ~180° folding during an in situ bending test, demonstrating a super-elasticity and ultraflexibility. We found that the origin of the super-elasticity was from the dynamic evolution of ferroelectric nanodomains. High stresses modulate the energy landscape markedly and allow the dipoles to rotate continuously between the a and c nanodomains. A continuous transition zone is formed to accommodate the variant strain and avoid high mismatch stress that usually causes fracture. The phenomenon should be possible in other ferroelectrics systems through domain engineering. The ultraflexible epitaxial ferroelectric membranes could enable many applications such as flexible sensors, memories, and electronic skins.

scholarly journals Additive Manufacturing-Based In Situ Consolidation of Continuous Carbon Fibre-Reinforced Polycarbonate

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2450
Author(s):  
Andreas Borowski ◽  
Christian Vogel ◽  
Thomas Behnisch ◽  
Vinzenz Geske ◽  
Maik Gude ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Carbon Fibre ◽  
Bending Test ◽  
Thermoplastic Composites ◽  
Experimental Investigations ◽  
Material Structure ◽  
Three Point Bending ◽  
Continuous Fibre ◽  
Local Material

Continuous carbon fibre-reinforced thermoplastic composites have convincing anisotropic properties, which can be used to strengthen structural components in a local, variable and efficient way. In this study, an additive manufacturing (AM) process is introduced to fabricate in situ consolidated continuous fibre-reinforced polycarbonate. Specimens with three different nozzle temperatures were in situ consolidated and tested in a three-point bending test. Computed tomography (CT) is used for a detailed analysis of the local material structure and resulting material porosity, thus the results can be put into context with process parameters. In addition, a highly curved test structure was fabricated that demonstrates the limits of the process and dependent fibre strand folding behaviours. These experimental investigations present the potential and the challenges of additive manufacturing-based in situ consolidated continuous fibre-reinforced polycarbonate.

In situ electrochemical microcantilever bending test: A new insight into hydrogen enhanced cracking

2017 ◽  
Vol 132 ◽  
pp. 17-21 ◽  
Author(s):  
Tarlan Hajilou ◽  
Yun Deng ◽  
Bjørn Rune Rogne ◽  
Nousha Kheradmand ◽  
Afrooz Barnoush
Keyword(s):  
Bending Test ◽  
Insight Into

scholarly journals Induced microearthquakes predict permeability creation in the brittle crust

2022 ◽  
Author(s):  
Ziyan Li ◽  
Derek Elsworth ◽  
Chaoyi Wang
Keyword(s):  
Patch Size ◽  
Dynamic Evolution ◽  
Permeability Evolution ◽  
Field Scale ◽  
Scale Invariant ◽  
Flow Paths ◽  
Porosity And Permeability ◽  
Hybrid Machine ◽  
Early Injection

Abstract Fracturing controls rates of mass, chemical and energy cycling within the crust. We use observed locations and magnitudes of microearthquakes (MEQs) to illuminate the evolving architecture of fractures reactivated and created in the otherwise opaque subsurface. We quantitatively link seismic moments of laboratory MEQs to the creation of porosity and permeability at field scale. MEQ magnitudes scale to the slipping patch size of remanent fractures reactivated in shear - with scale-invariant roughnesses defining permeability evolution across nine decades of spatial volumes – from centimeter to decameter scale. This physics-inspired seismicity-permeability linkage enables hybrid machine learning (ML) to constrain in-situ permeability evolution at verifiable field-scales (~10 m). The ML model is trained on early injection and MEQ data to predict the dynamic evolution of permeability from MEQ magnitudes and locations, alone. The resulting permeability maps define and quantify flow paths verified against ground truths of permeability.

scholarly journals Predicted ripple dimensions in relation to the precision of in situ measurements

2016 ◽  
Author(s):  
Knut Krämer ◽  
Christian Winter
Keyword(s):  
Dynamic Evolution ◽  
Sediment Properties ◽  
Hydraulic Roughness ◽  
Empirical Relations ◽  
Digital Elevation ◽  
Shelf Sea ◽  
Waves And Currents ◽  
Order Of Magnitude ◽  
Accuracy Of Measurement

Abstract. Ripples are common morphological features in sandy marine environments. Their shapes and dimensions are closely related to local sediment properties and the forcing by waves and currents. Numerous predictors for the geometry and hydraulic roughness of ripples exist but due to their empirical nature, they may fail to properly reflect conditions in the field. Here, situ measurements of ripple dimensions and their dynamics in a shallow shelf sea are reported. Technical and methodological limits of the detection of ripple dimensions and their dynamic evolution due to changing forcing are assessed. Methods of bed detection from sonar data and analysis of ripple dimensions in digital elevation models (DEM) are compared and evaluated. The range of measured ripple dimensions is quantified and compared to results of traditional and recent empirical predictors. The precision of measurements of bedform dimensions is taken as the repeatability of a measurement for inactive conditions and the accuracy of measurement is assessed via comparison to predicted dimensions. The precision of detection is limited to 10 % of the absolute ripple dimensions. The order of magnitude of the ripple dimension can be predicted by the empirical relations. However, these tend to return the height of the largest ripples rather than average heights. The application of different methods for detection of heights may result in derived form roughness heights by up to a factor of two.

scholarly journals AFM In-situ Bending Test on Deformation Behavior of Polyethylene Lamellar Structure

2004 ◽  
Vol 53 (12) ◽  
pp. 1359-1364 ◽  
Author(s):  
Kisaragi YASHIRO ◽  
Masayuki KANAI ◽  
Yoshihiro TOMITA
Keyword(s):  
Deformation Behavior ◽  
Lamellar Structure ◽  
Bending Test

Twinning Behavior in AZ31-B Polycrystal Texture Subjected to In-Situ Bending Test

2010 ◽  
Vol 654-656 ◽  
pp. 715-718 ◽  
Author(s):  
Itsuya Sato ◽  
Seiji Miura ◽  
Tetsuo Mohri
Keyword(s):  
Bending Test ◽  
Confocal Scanning Laser Microscope ◽  
Compression Strain ◽  
Bending Process ◽  
Axis Compression ◽  
Confocal Scanning ◽  
Plane Plastic ◽  
Extension Strain ◽  
Confocal Scanning Laser

A commercial Mg alloy, AZ31B, has been used widely. In the texture of AZ31B sheet, each grain has its c-axis almost parallel to the sheet normal. Therefore, at the bending process of the sheet, basal slip system can not accommodate an in-plane plastic strain which is perpendicular to the c-axis of each grain. It is known that {10―,12} twin can be formed by applying an extension strain parallel to the c-axis, which is equivalent to the a-axis compression strain. So in the bending deformation of the AZ31B sheet with a texture microstructure, it is expected that {10―,12} twinning occurs. In this study, an in-situ bending test of AZ31B sheet with a texture was conducted under a confocal scanning laser microscope to observe twinning by applying compression stress along a direction almost perpendicular to the c-axis of grains. In addition, EBSD techniques were used for the analysis of crystal orientations. The process of twin development observed by the in-situ bending test can be summarized as follows; with the increase of the deformation strain, the total area of twins increases. However, it is noted that the growth of twins is apparent while the number of twins is almost constant during plastic bending deformmation. EBSD analysis suggested that twinning behavior obey Schmid’s law even in the polycrystal.

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

2017 ◽  
Vol 375 (2098) ◽  
pp. 20160410 ◽  
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’.

Structural analysis of elastically bent organic crystals using in situ indentation and micro-Raman spectroscopy

2017 ◽  
Vol 53 (97) ◽  
pp. 13035-13038 ◽  
Author(s):  
Manish Kumar Mishra ◽  
Kamini Mishra ◽  
S. A. Syed Asif ◽  
Praveena Manimunda
Keyword(s):  
Raman Spectroscopy ◽  
Structural Analysis ◽  
Structural Dynamics ◽  
Bending Test ◽  
Organic Crystals ◽  
Three Point Bending ◽  
Micro Raman Spectroscopy

The structural dynamics of two elastically bendable, halogenated N-benzylideneaniline organic crystals were studied using an in situ three-point bending test and Raman spectroscopy.

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