| Records |
| Author |
Shi, H.; Frenzel, J.; Martinez, G.T.; Van Rompaey, S.; Bakulin, A.; Kulkova, A.; Van Aert, S.; Schryvers, D. |
| Title |
Site occupation of Nb atoms in ternary Ni-Ti-Nb shape memory alloys |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
| Volume |
74 |
Issue |
|
Pages |
85-95 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Nb occupancy in the austenite B2-NiTi matrix and Ti2Ni phase in NiTiNb shape memory alloys was investigated by aberration-corrected scanning transmission electron microscopy and precession electron diffraction. In both cases, Nb atoms were found to prefer to occupy the Ti rather than Ni sites. A projector augmented wave method within density functional theory was used to calculate the atomic and electronic structures of the austenitic B2-NiTi matrix phase and the Ti2Ni precipitates both with and without addition of Nb. The obtained formation energies and analysis of structural and electronic characteristics explain the preference for Ti sites for Nb over Ni sites. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Oxford |
Editor |
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| Language |
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Wos |
000338621400009 |
Publication Date |
2014-05-08 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1359-6454; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
5.301 |
Times cited |
21 |
Open Access |
|
| Notes |
|
Approved  |
Most recent IF: 5.301; 2014 IF: 4.465 |
| Call Number |
UA @ lucian @ c:irua:118334 |
Serial |
3028 |
| Permanent link to this record |
| |
|
| |
| Author |
Wang, X.; Kustov, S.; Li, K.; Schryvers, D.; Verlinden, B.; Van Humbeeck, J. |
| Title |
Effect of nanoprecipitates on the transformation behavior and functional properties of a Ti50.8 at.% Ni alloy with micron-sized grains |
Type |
A1 Journal article |
| Year |
2015 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
| Volume |
82 |
Issue |
82 |
Pages |
224-233 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
In order to take advantage of both grain refinement and precipitation hardening effects, nanoscaled Ni4Ti3 precipitates are introduced in a Ti50.8 at.% Ni alloy with micron-sized grains (average grain size of 1.7 μm). Calorimetry, electrical resistance studies and thermomechanical tests were employed to study the transformation behavior and functional properties in relation to the obtained microstructure. A significant suppression of martensite transformation by the obtained microstructure is observed. The thermomechanical tests show that the advantageous properties of both grain refinement and precipitation hardening are combined in the developed materials, resulting in superior shape memory characteristics and stability of pseudoelasticity. It is concluded that introducing nanoscaled Ni4Ti3 precipitates into small grains is a new approach to improve the functional properties of NiTi shape memory alloys. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Oxford |
Editor |
|
| Language |
|
Wos |
000347017800021 |
Publication Date |
2014-10-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1359-6454; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
5.301 |
Times cited |
51 |
Open Access |
|
| Notes |
Fwo |
Approved |
Most recent IF: 5.301; 2015 IF: 4.465 |
| Call Number |
c:irua:120469 |
Serial |
824 |
| Permanent link to this record |
| |
|
| |
| Author |
Pollefeyt, G.; Meledin, A.; Pop, C.; Ricart, S.; Hühne, R.; Van Tendeloo, G.; Van Driessche, I. |
| Title |
Chemical stability of YBiO3 buffer layers for implementation in YBa2Cu3O7-δ coated conductors |
Type |
A1 Journal article |
| Year |
2015 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
| Volume |
100 |
Issue |
100 |
Pages |
224-231 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
In this work, the chemical and microstructural stability of YBiO3 buffer layers during the growth of YBa2Cu3O7-δ (YBCO) was studied. The superconducting YBCO films were deposited via both Pulsed Laser Deposition as well as Chemical Solution Deposition. Although excellent superconducting properties are obtained in both cases, self-field critical current densities of 3.6 and 1.2 MA/cm2 respectively, chemical instability of the YBiO3 buffer layer is observed. An elaborate transmission electron microscopy study showed that in the case of vacuum deposited YBCO, the YBiO3 becomes unstable and Bi2O3 sublimates out of the architecture. Due to this structural instability, an intermediate Y2O3 layer is obtained which maintains it microstructural orientation relation with the substrate and acts as growth template for YBCO. For chemical solution deposited YBCO, reaction of YBCO with the YBiO3 buffer layer is observed, leading to large grains of YBa2BiO6 which are pushed towards the surface of the films and strongly reduce the superconducting properties. Upon using high growth temperatures for the superconducting layer, these secondary phases decompose, which subsequently leads to Bi2O3 sublimation and a textured YBCO film which directly nucleated onto the LaAlO3 single crystal substrate. Hence, this electron microscopy study indicates that bismuth-based buffer layers systems are not suitable for implementation in coated conductors. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000362616400023 |
Publication Date |
2015-08-29 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1359-6454; |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
5.301 |
Times cited |
|
Open Access |
|
| Notes |
One of the authors (G.P.) would like to thank the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT) for funding. Part of this work was performed within the framework of the EuroTapes project (FP7-NMP.2011.2.2-1 Grant No. 280438), funded by the European Union. |
Approved |
Most recent IF: 5.301; 2015 IF: 4.465 |
| Call Number |
c:irua:128757 |
Serial |
3953 |
| Permanent link to this record |
| |
|
| |
| Author |
Choisez, L.; Ding, L.; Marteleur, M.; Kashiwar, A.; Idrissi, H.; Jacques, P.J. |
| Title |
Shear banding-activated dynamic recrystallization and phase transformation during quasi-static loading of β-metastable Ti – 12 wt % Mo alloy |
Type |
A1 Journal article |
| Year |
2022 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
| Volume |
235 |
Issue |
|
Pages |
118088-13 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Dynamic recrystallization (DRX) within adiabatic shear bands forming during the fracture of TRIP-TWIP β−metastable Ti-12Mo (wt %) alloy was recently reported. The formation of 1-3 µm thick-adiabatic shear bands, and of dynamic recrystallization, was quite surprising as their occurrence generally requires high temperature and/or high strain rate loading while these samples were loaded in quasi-static conditions at room temperature. To better understand the fracture mechanism and associated microstructural evolution, thin foils representative of different stages of the fracture process were machined from the fracture surface by Focused Ion Beam (FIB) and analyzed by Transmission Electron Microscopy (TEM) and Automated Crystal Orientation mapping (ACOM-TEM). Complex microstructure transformations involving severe plastic deformed nano-structuration, crystalline rotation and local precipitation of the omega phase were identified. The spatial and temporal evolution of the microstructure during the propagation of the crack was explained through dynamic recovery and continuous dynamic recrystallization, and linked to the modelled distribution of temperature and strain level where TEM samples were extracted. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000814729300005 |
Publication Date |
2022-06-05 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1359-6454 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
9.4 |
Times cited |
|
Open Access |
OpenAccess |
| Notes |
|
Approved |
Most recent IF: 9.4 |
| Call Number |
UA @ admin @ c:irua:188505 |
Serial |
7096 |
| Permanent link to this record |
| |
|
| |
| Author |
Arseenko, M.; Hannard, F.; Ding, L.; Zhao, L.; Maire, E.; Villanova, J.; Idrissi, H.; Simar, A. |
| Title |
A new healing strategy for metals : programmed damage and repair |
Type |
A1 Journal article |
| Year |
2022 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
| Volume |
238 |
Issue |
|
Pages |
118241-10 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Self-healing strategies aim at avoiding part repair or even replacement, which is time consuming, expen-sive and generates waste. However, strategies for metallic systems are still under-developed and solid-state solutions for room temperature service are limited to nano-scale damage repair. Here we propose a new healing strategy of micron-sized damage requiring only short and low temperature heating. This new strategy is based on damage localization particles, which can be healed by fast diffusing atoms of the matrix activated during heat treatment. The healing concept was successfully validated with a com-mercial aluminum alloy and manufactured by Friction Stir Processing (FSP). Damage was demonstrated to initiate on particles that were added to the matrix during material processing. In situ 2D and 3D nano -imaging confirmed healing of the damaged material and showed that heating this material for 10 min at 400 degrees C is sufficient to heal incipient damage with complete filling of 70% of all damage (and up to 90% when their initial size is below 0.2 mu m). Furthermore, strength is retained and the work of fracture of the alloy is improved by about 40% after healing. The proposed Programmed Damage and Repair healing strategy could be extended to other metal based systems presenting precipitation. (C) 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
|
Wos |
000843502700006 |
Publication Date |
2022-08-03 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1359-6454 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
9.4 |
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 9.4 |
| Call Number |
UA @ admin @ c:irua:190561 |
Serial |
7121 |
| Permanent link to this record |
| |
|
| |
| Author |
Idrissi, H.; Béché, A.; Gauquelin, N.; Ul-Haq, I.; Bollinger, C.; Demouchy, S.; Verbeeck, J.; Pardoen, T.; Schryvers, D.; Cordier, P. |
| Title |
On the formation mechanisms of intragranular shear bands in olivine by stress-induced amorphization |
Type |
A1 Journal article |
| Year |
2022 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Mater |
| Volume |
239 |
Issue |
|
Pages |
118247-118249 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Intragranular amorphization shear lamellae are found in deformed olivine aggregates. The detailed trans-mission electron microscopy analysis of intragranular lamella arrested in the core of a grain provides novel information on the amorphization mechanism. The deformation field is complex and heteroge-neous, corresponding to a shear crack type instability involving mode I, II and III loading components. The formation and propagation of the amorphous lamella is accompanied by the formation of crystal defects ahead of the tip. These defects are geometrically necessary [001] dislocations, characteristics of high-stress deformation in olivine, and rotational nanodomains which are tentatively interpreted as disclinations. We show that these defects play an important role in dictating the path followed by the amorphous lamella. Stress-induced amorphization in olivine would thus result from a direct crystal-to -amorphous transformation associated with a shear instability and not from a mechanical destabilization due to the accumulation of high number of defects from an intense preliminary deformation. The pref-erential alignment of some lamellae along (010) is a proof of the lower ultimate mechanical strength of these planes.(c) 2022 The Authors. Published by Elsevier Ltd on behalf of Acta Materialia Inc. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ ) |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
|
Wos |
000861076600004 |
Publication Date |
2022-08-05 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1359-6454 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
9.4 |
Times cited |
5 |
Open Access |
OpenAccess |
| Notes |
The QuanTEM microscope was partially funded by the Flemish government. The K2 camera was funded by FWO Hercules fund G0H4316N 'Direct electron detector for soft matter TEM'. A. Beche acknowledges funding from FWO project G093417N ('Compressed sensing enabling low dose imaging in transmission electron microscopy'). H. Idrissi is mandated by the Belgian National Fund for Scientific Research (FSR-FNRS). This work was supported by the FNRS under Grant PDR – T011322F and by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme under grant agreement No 787,198 Time Man. J-L Rouviere is acknowledged for his support with the GPA softawre. |
Approved |
Most recent IF: 9.4 |
| Call Number |
UA @ admin @ c:irua:191432 |
Serial |
7186 |
| Permanent link to this record |
| |
|
| |
| Author |
Cautaerts, N.; Delville, R.; Stergar, E.; Pakarinen, J.; Verwerft, M.; Yang, Y.; Hofer, C.; Schnitzer, R.; Lamm, S.; Felfer, P.; Schryvers, D. |
| Title |
The role of Ti and TiC nanoprecipitates in radiation resistant austenitic steel: A nanoscale study |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Acta Materialia |
Abbreviated Journal |
Acta Mater |
| Volume |
197 |
Issue |
|
Pages |
184-197 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
This work encompasses an in-depth transmission electron microscopy and atom probe tomography study of Ti-stabilized austenitic steel irradiated with Fe-ions. The focus is on radiation induced segregation and precipitation, and in particular on how Ti and TiC affect these processes. A 15-15Ti steel (grade: DIN 1.4970) in two thermo-mechanical states (cold-worked and aged) was irradiated at different temperatures up to a dose of 40 dpa. At low irradiation temperatures, the cold-worked and aged materials evolved to a similar microstructure dominated by small Si and Ni clusters, corresponding to segregation to small point defect clusters. TiC precipitates, initially present in the aged material, were found to be unstable under these irradiation conditions. Elevated irradiation temperatures resulted in the nucleation of nanometer sized Cr enriched TiC precipitates surrounded by Si and Ni enriched shells. In addition, nanometer sized Ti- and Mn-enriched G-phase (M6Ni16Si7) precipitates formed, often attached to TiC precipitates. Post irradiation, larger number densities of TiC were observed in the cold-worked material compared to the aged material. This was correlated with a lower volume fraction of G-phase. The findings suggest that at elevated irradiation temperatures, the precipitate-matrix interface is an important point defect sink and contributes to the improved radiation resistance of this material. The study is a first of its kind on stabilized steel and demonstrates the significance of the small Ti addition to the evolution of the microstructure under irradiation. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000564767000001 |
Publication Date |
2020-07-10 |
| Series Editor |
|
Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1359-6454 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
9.4 |
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
; This work was supported by ENGIE [contract number 2015-AC-007 e BSUEZ6900]; the U.S. Department of Energy, Office of Nuclear Energy under DOE Idaho Operations Office Contract DE-AC07051D14517 as part of a Nuclear Science User Facilities experiment; and by the MYRRHA program at SCK-CEN, Belgium. Funding of the Austrian BMK (846933) in the framework of the program “Production of the future” and the “BMK Professorship for Industry” is gratefully acknowledged. We want to thank the staffat MIBL for assisting with the ion irradiations as well as the staffat CAES for assisting with FIB work and conducting APT measurements. ; |
Approved |
Most recent IF: 9.4; 2020 IF: 5.301 |
| Call Number |
UA @ admin @ c:irua:171956 |
Serial |
6626 |
| Permanent link to this record |
| |
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| |
| Author |
Mary Joy, R.; Pobedinskas, P.; Baule, N.; Bai, S.; Jannis, D.; Gauquelin, N.; Pinault-Thaury, M.-A.; Jomard, F.; Sankaran, K.J.; Rouzbahani, R.; Lloret, F.; Desta, D.; D’Haen, J.; Verbeeck, J.; Becker, M.F.; Haenen, K. |
| Title |
The effect of microstructure and film composition on the mechanical properties of linear antenna CVD diamond thin films |
Type |
A1 Journal article |
| Year |
2024 |
Publication |
Acta materialia |
Abbreviated Journal |
Acta Materialia |
| Volume |
264 |
Issue |
|
Pages |
119548 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
This study reports the impact of film microstructure and composition on the Young’s modulus and residual stress in nanocrystalline diamond (NCD) thin films ( thick) grown on silicon substrates using a linear antenna microwave plasma-enhanced chemical vapor deposition (CVD) system. Combining laser acoustic wave spectroscopy to determine the elastic properties with simple wafer curvature measurements, a straightforward method to determine the intrinsic stress in NCD films is presented. Two deposition parameters are varied: (1) the substrate temperature from 400 °C to 900 °C, and (2) the [P]/[C] ratio from 0 ppm to 8090 ppm in the H2/CH4/CO2/PH3 diamond CVD plasma. The introduction of PH3 induces a transition in the morphology of the diamond film, shifting from NCD with larger grains to ultra-NCD with a smaller grain size, concurrently resulting in a decrease in Young’s modulus. Results show that the highest Young’s modulus of (113050) GPa for the undoped NCD deposited at 800 °C is comparable to single crystal diamond, indicating that NCD with excellent mechanical properties is achievable with our process for thin diamond films. Based on the film stress results, we propose the origins of tensile intrinsic stress in the diamond films. In NCD, the tensile intrinsic stress is attributed to larger grain size, while in ultra-NCD films the tensile intrinsic stress is due to grain boundaries and impurities. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
001126632800001 |
Publication Date |
2023-11-23 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
|
| ISSN |
1359-6454 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
9.4 |
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
This work was financially supported by the Special Research Fund (BOF) via Methusalem NANO network, the Research Foundation – Flanders (FWO) via Project G0D4920N, and the CORNET project nr 263-EN “ULTRAHARD: Ultrahard optical diamond coatings” (2020–2021). |
Approved |
Most recent IF: 9.4; 2024 IF: 5.301 |
| Call Number |
EMAT @ emat @c:irua:202169 |
Serial |
8989 |
| Permanent link to this record |
| |
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| |
| Author |
Coulombier, M.; Baral, P.; Orekhov, A.; Dohmen, R.; Raskin, J.P.; Pardoen, T.; Cordier, P.; Idrissi, H. |
| Title |
On-chip very low strain rate rheology of amorphous olivine films |
Type |
A1 Journal article |
| Year |
2024 |
Publication |
Acta materialia |
Abbreviated Journal |
|
| Volume |
266 |
Issue |
|
Pages |
119693-12 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
| Abstract |
Recent observations made by the authors revealed the activation of stress induced amorphization and sliding at grain boundary in olivine [1], a mechanism which is expected to play a pivotal role in the viscosity drop at the lithosphere-asthenosphere boundary and the brittle -ductile transition in the lithospheric mantle. However, there is a lack of information in the literature regarding the intrinsic mechanical properties and the elementary deformation mechanisms of this material, especially at time scales relevant for geodynamics. In the present work, amorphous olivine films were obtained by pulsed laser deposition (PLD). The mechanical response including the rate dependent behavior are investigated using a tension -on -chip (TOC) method developed at UCLouvain allowing to perform creep/relaxation tests on thin films at extremely low strain rates. In the present work, strain rate down to 10-12 s- 1 was reached which is unique. High strain rate sensitivity of 0.054 is observed together with the activation of relaxation at the very early stage of deformation. Furthermore, digital image correlation (DIC), used for the first time on films deformed by TOC, reveals local strain heterogeneities. The relationship between such heterogeneities, the high strain rate sensitivity and the effect of the electron beam in the scanning electron microscope is discussed and compared to the literature. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
001170513400001 |
Publication Date |
2024-01-17 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1359-6454 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
9.4 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 9.4; 2024 IF: 5.301 |
| Call Number |
UA @ admin @ c:irua:204864 |
Serial |
9163 |
| Permanent link to this record |
