Article
Materials Science, Multidisciplinary
Y. Aboura, A. J. Garner, R. Euesden, Z. Barrett, C. Engel, N. J. H. Holroyd, P. B. Prangnell, T. L. Burnett
Summary: New-gen 7xxx series alloys have shown higher susceptibility to environmental assisted cracking (EAC) in humid air compared to AA7050 in T7651 tempers. Hydrogen (H)-EAC fracture features of brittle intergranular (IG) and transgranular (TG) fracture modes were observed with humidity levels as low as 20%. The difficulty of crack initiation in AA7050 was attributed to its grain structure and intrinsic resistance of the grain boundaries to IG-EAC.
Article
Nanoscience & Nanotechnology
Marti Lopez Freixes, Xuyang Zhou, Raquel Aymerich-Armengol, Miquel Vega-Paredes, Lionel Peguet, Timothy Warner, Baptiste Gault
Summary: Crack growth in stress corrosion cracking (SCC) in 7xxx Al alloys is an intermittent process. When crack propagation stops, hydrogen (H) is generated at the crack tip, facilitating further crack advancement through hydrogen embrittlement. CAMs are produced through oxidation at the arrested crack tip, with matrix precipitates dissolving and solute diffusing towards the growing CAM. Residual strain beneath the fracture surface indicates non-localized plastic activity. Findings suggest that H induces crack propagation through decohesion.
SCRIPTA MATERIALIA
(2023)
Article
Materials Science, Multidisciplinary
R. T. Euesden, Y. Aboura, A. J. Garner, T. Jailin, C. Grant, Z. Barrett, C. Engel, P. Shanthraj, N. J. H. Holrlyd, P. B. Prangnell, T. L. Bngnella
Summary: Large area, time resolved, in-situ optical scanning of constant displacement tests were conducted to monitor the environmentally assisted cracking (EAC) behavior of AA7085 and AA7449 T7651 thick plate materials. It was found that cracks initiated at surface connected gas pore clusters and reactive Mg-containing constituent intermetallic compounds on grain boundaries. The research also showed that cracks can grow at stress intensities below the KIEAC threshold measured via DCB testing.
Article
Materials Science, Multidisciplinary
Evgeniy Merson, Vitaliy Poluyanov, Pavel Myagkikh, Dmitri Merson, Alexei Vinogradov
Summary: The study demonstrates that stress-corrosion cracking (SCC) in magnesium and its alloys during slow-strain rate tensile testing in air is related to hydrogen embrittlement and the corrosion product layer. However, the complete recovery of mechanical response and elimination of harmful embrittling features can be achieved by removing corrosion products from the surface of pre-exposed specimens, which challenges the common viewpoint that SCC mechanism is solely governed by diffusible hydrogen.
Article
Materials Science, Multidisciplinary
Yitong Shi, Sudha Joseph, Edward A. Saunders, Rebecca S. Sandala, Adrian Walker, Trevor C. Lindley, David Dye
Summary: The mechanism of AgCl-induced stress corrosion cracking of Ti-6246 involves the formation and migration of metallic Ag along the crack, as well as the presence of SnO2 and Al2O3 corrosion products mixed into TiO2. The fracture surface exhibits a transgranular nature with a brittle appearance in the primary alpha phase, where long, straight and non-interacting dislocations are observed. This is consistent with a dislocation emission view of the cracking mechanism.
Article
Materials Science, Multidisciplinary
Alistair Garner, Ryan Euesden, Yichao Yao, Yasser Aboura, Huan Zhao, Jack Donoghue, Michele Curioni, Baptiste Gault, Pratheek Shanthraj, Zak Barrett, Christian Engel, Tim L. Burnett, Phil B. Prangnell
Summary: The size, distribution, and chemical composition of grain boundary-phase precipitates (GBPs) and micro-segregation in two different aluminum alloys have been studied. It was found that the GBPs in AA7050 are larger and more complex, with higher levels of copper and aluminum and lower zinc content compared to AA7085. Limited grain boundary segregation was observed, mainly attributed to differences in the chemical composition of the large Q-GBPs between the two materials.
Article
Materials Science, Multidisciplinary
Tianliang Zhao, Shiqi Wang, Zhiyong Liu, Cuiwei Du, Xiaogang Li
Summary: The study investigated the effect of cathodic polarisation on stress corrosion cracking behavior of peak-aged Ni(Fe, Al)-maraging steel in artificial seawater. It found that the steel exhibits better compatibility of strength and hydrogen embrittlement resistance due to the abundant and evenly dispersed Ni(Fe, Al) nanoprecipitates. The mechanism of SCC at different potentials and a novel model for interpreting hydrogen embrittlement were proposed.
Article
Chemistry, Physical
Shinnosuke Yamamoto, Daiki Taniguchi, Takahiro Ozawa, Kaito Hirata, Takahiro Ozawa, Takeshi Fukuma
Summary: By directly observing nanoscale structures and changes in potential, we clarify the mechanism of grain boundary corrosion in Al alloy. The experiment confirms the anodic dissolution of MgZn2 precipitates and the erosion of grain boundaries driven by hydrogen embrittlement. This understanding can improve the susceptibility of Al alloys to stress corrosion cracking originating from grain boundary corrosion.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Mahdieh Safyari, Masoud Moshtaghi, Shigeru Kuramoto
Summary: The study found that by controlling the distribution of soluble second phase particles, the hydrogen embrittlement resistance of the alloy can be improved, but an excessive increase in second phase particles can make the alloy more sensitive to hydrogen embrittlement.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
Alistair Garner, Jack Donoghue, Remco Geurts, Yasser Al Aboura, Bartlomiej Winiarski, Phil B. Prangnell, Tim L. Burnett
Summary: In this study, large scale serial sectioning using laser PFIB was conducted to investigate the environmentally-assisted cracking (EAC) of 7xxx aluminium aerospace alloys. The results showed that the grains in these alloys are larger and more complex than previously known, and the interaction between cracks and microstructure can cause significant crack deflection, which may explain the observed differences in EAC behavior.
MATERIALS CHARACTERIZATION
(2022)
Article
Materials Science, Multidisciplinary
Kyosuke Hirayama, Hiroyuki Toda, Dongsheng Fu, Ryohei Masunaga, Hang Su, Kazuyuki Shimizu, Akihisa Takeuchi, Masayuki Uesugi
Summary: The research showed that Al-10Mg alloys are highly susceptible to stress corrosion cracking after hydrogen charging, with observation of hydrogen bubble formation at the crack tip and both intergranular and transgranular fractures. Additionally, the main corrosion product in the aquatic environment was identified as Al(OH)3, and accurate measurement of corrosion products, hydrogen gas in bubbles, and solution pH during in-situ tensile testing enabled estimation of local hydrogen content elevation in the crack tip vicinity.
Article
Materials Science, Multidisciplinary
Kazuyuki Shimizu, Hiroyuki Toda, Hiro Fujihara, Masatake Yamaguchi, Masayuki Uesugi, Akihisa Takeuchi, Masahiko Nishijima, Yasuhiro Kamada
Summary: This study proposes a novel technique of using Mn-based second-phase particle dispersion to prevent hydrogen embrittlement in 7xxx aluminum alloys. By comparing the deformation and fracture behaviors of 0.0% Mn and 0.6% Mn alloys, it is found that the addition of Mn significantly reduces hydrogen-induced fractures, as quantitatively analyzed based on hydrogen partitioning.
Article
Materials Science, Multidisciplinary
Y. Aboura, D. F. Martelo, R. Morana, R. Akid, K. L. Moore
Summary: This study investigated the hydrogen induced cracking behavior of O&G nickel alloy 625+ (UNS N07716) using deuterium as an isotopic tracer. The results showed enrichments at dislocation slip bands, twin boundary, and grain boundary features, providing experimental evidence of the phenomenon. Analysis using scanning electron microscopy and energy dispersive X-ray techniques helped in identifying the microstructural features corresponding to deuterium enrichments.
Article
Nanoscience & Nanotechnology
A. Drexler, S. He, R. Pippan, L. Romaner, V. I. Razumovskiy, W. Ecker
Summary: The study investigates the effect of severe elastic straining of interstitial lattice sites in front of a crack tip in nickel, which significantly affects hydrogen segregation in the first atomic layers. The hydrogen distribution in the process zone is found to be strongly inhomogeneous with full occupation of free surface sites and volumetric strained sites.
SCRIPTA MATERIALIA
(2021)
Article
Construction & Building Technology
Zhong Li, Baozhuang Sun, Qi Liu, Yifan Yu, Zhiyong Liu
Summary: The study found that square wave polarization (SWP) with alternative stages of pulse current and stable current period plays different roles in stress corrosion cracking (SCC) of pipeline steels. The former mainly contributes to the local anodic dissolution process, while the latter strengthens the cathodic hydrogen evolution process.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
K. N. Sasidhar, Heena Khanchandani, Siyuan Zhang, Alisson Kwiatkowski da Silva, C. Scheu, Baptiste Gault, Dirk Ponge, Dierk Raabe
Summary: We conducted high-resolution structural and chemical characterization of the oxide films on a ferritic Fe-13 at% Cr alloy at different growth stages. The protective oxide film was found to be 5-6 nm thick, epitaxially grown with a cubic spinel-structure, and had a Baker-Nutting orientation-relationship with the alloy. The composition evolution within the oxide was explained by the low solid-state mobility of Cr3+ cations, suggesting the miscibility gap in the Fe-Cr spinel oxide solid-solution as a cause for the reduced driving force for oxide-layer thickening over time.
Article
Materials Science, Multidisciplinary
Baptiste Gault, Heena Khanchandani, Thoudden Sukumar Prithiv, Stoichko Antonov, T. Ben Britton
Summary: Measuring local chemistry of specific crystallographic features by atom probe tomography (APT) is aided by transmission Kikuchi diffraction (TKD), but the potential structural damage caused by TKD is often ignored. Two case studies demonstrate damage in APT specimens from TKD mapping. The damage includes planar segregation of solutes and the formation of voids containing high concentrations of a specific element.
MICROSCOPY AND MICROANALYSIS
(2023)
Article
Materials Science, Multidisciplinary
James O. Douglas, Michele Conroy, Finn Giuliani, Baptiste Gault
Summary: Workflows have been developed in the past decade to enable atom probe tomography analysis at cryogenic temperatures. The inability to control the local deposition of the metallic precursor from the gas-injection system (GIS) at cryogenic temperatures makes the preparation of site-specific specimens by using lift-out extremely challenging in the focused-ion beam. Schreiber et al. exploited redeposition to weld the lifted-out sample to a support.
MICROSCOPY AND MICROANALYSIS
(2023)
Article
Materials Science, Multidisciplinary
Felipe F. Morgado, Leigh Stephenson, Loic Rousseau, Francois Vurpillot, Simon Evertz, Jochen M. Schneider, Baptiste Gault
Summary: In this study, a chemically resolved atomic resolution imaging technique is developed by combining the atomic spatial resolution of field ion microscopy with the time-of-flight spectrometry of atom probe tomography. By implementing specialized flight path corrections and filtering algorithms, the performance of the technique is improved, leading to a significant increase in signal-to-background ratio. This technique not only enables the differentiation and identification of isotopes in pure tungsten, but also allows for elemental identification in non-metallic materials and binary alloys.
MICROSCOPY AND MICROANALYSIS
(2023)
Article
Materials Science, Multidisciplinary
Se-Ho Kim, Leigh T. Stephenson, Torsten Schwarz, Baptiste Gault
Summary: This study compared the distribution of constituent elements in two different smartphone glass samples using X-ray spectroscopy techniques and atom probe tomography (APT). The results demonstrated that APT can be considered as an alternative technique for imaging the chemical distribution in glass for mobile applications.
MICROSCOPY AND MICROANALYSIS
(2023)
Article
Nanoscience & Nanotechnology
Hanna Bishara, Lena Langenohl, Xuyang Zhou, Baptiste Gault, James P. Best, Gerhard Dehm
Summary: The study focuses on the effect of Fe-alloying on the resistivities of grains and grain boundaries in Cu thin films. Cu films with varying grain sizes and Fe compositions were prepared. The properties, morphology, and compositions of bulk and grain boundaries were analyzed using different methods. Both local electrical measurements and global resistivity characterization were performed to obtain specific resistivities and calculate the grain boundary reflection coefficient. It was found that alloying significantly increased the resistivity of grain boundaries while causing only minor influence on the grain interior.
SCRIPTA MATERIALIA
(2023)
Article
Multidisciplinary Sciences
Xuyang Zhou, Ali Ahmadian, Baptiste Gault, Colin Ophus, Christian H. Liebscher, Gerhard Dehm, Dierk Raabe
Summary: Grain boundaries, the defects between differently oriented crystals, play an important role in solute segregation and material properties. The interplay of structure and composition of grain boundaries at the atomic level remains unclear. Through charge-density imaging and atom probe tomography, the authors reveal that the atomic motifs control the chemical properties of grain boundaries and enable the targeted design and passivation for various applications.
NATURE COMMUNICATIONS
(2023)
Article
Geochemistry & Geophysics
Renelle Dubosq, David A. Schneider, Alfredo Camacho, Baptiste Gault
Summary: The deformation mechanisms of garnet in the brittle-ductile regime under lower crustal conditions are still unclear. A study on garnet porphyroclasts from an eclogite facies mylonite in central Australia reveals that Fe segregation along grain boundaries of garnet leads to the nucleation of Fe-rich nanoclusters, which act as barriers for migrating dislocations, resulting in strain hardening and mechanical failure.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Eric Woods, Mahander P. Singh, Se-Ho Kim, Tim M. Schwarz, James O. Douglas, Ayman A. El-Zoka, Finn Giulani, Baptiste Gault
Summary: This study focuses on the challenges of preparing cryogenic specimens for atom probe tomography (APT), and presents a generalized workflow for cryogenic specimen preparation. The workflow includes lift-out via focused ion beam and in situ deposition of capping layers to strengthen specimens and protect them during transfer. The study demonstrates the reliable in situ deposition of a metallic capping layer and showcases its significant improvement in atom probe data quality.
MICROSCOPY AND MICROANALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Chaohua Zhang, Qiangwen Lai, Wu Wang, Xuyang Zhou, Kailiang Lan, Lipeng Hu, Bowen Cai, Matthias Wuttig, Jiaqing He, Fusheng Liu, Yuan Yu
Summary: This work reports on the strengthening of mechanical robustness in Bi2Te3-based alloys due to thermodynamic Gibbs adsorption and kinetic Zener pinning at grain boundaries enabled by MgB2 decomposition. The addition of MgB2 results in refined grain size and improved compressive strength and hardness. Moreover, MgB2 facilitates the optimization of electron and phonon transport for enhancing the thermoelectric figure of merit. The study shows promising results for the fabrication of robust thermoelectric devices with high energy conversion efficiency.
Review
Immunology
Ting Cao, Xuyang Zhou, Xingbiao Wu, Ying Zou
Summary: The development of immune checkpoint inhibitors (ICIs) has significantly changed the treatment landscape for multiple malignancies. However, ICIs can also lead to immune-related adverse events (irAEs), especially affecting the skin. This review explores the immunological mechanisms and potential biomarkers for predicting cutaneous irAEs using multi-omics approaches. Additionally, the prognostic significance of cutaneous irAEs in immune checkpoint blockade therapy is discussed.
FRONTIERS IN IMMUNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Stoichko Antonov, T. S. Prithiv, Xuyang Zhou, Andrew Peterson, Baptiste Gault, Ian Baker
Summary: Heat resistant steels are widely used in the energy production industry, and the goal of next-generation alloy design is to increase their temperature capability while maintaining low component costs. By controlling the precipitation and microstructural evolution, the creep lifetime of alumina-forming-austenitic stainless steels can be improved. The current research aims to understand the transformation pathways of a specific alloy during aging and creep at 750°C/45 MPa.
Article
Engineering, Electrical & Electronic
Naixin Yi, Wei Sun, Xuyang Zhou, Long Chen, Jiguan Zhang, Dong Han, Changhao Sun
Summary: This article proposes a double-layer attitude estimation algorithm based on error states, utilizing a decoupled direction cosine matrix (DCM) as the output. The algorithm addresses the limitations of traditional attitude calculation methods, reducing nonlinear errors and susceptibility to magnetic interference. It introduces a novel attitude angle decoupling method of DCM, which retains the advantages of DCM while reducing dimensionality and nonlinearity. The article applies these concepts to both extended Kalman filter (EKF) and unscented Kalman filter (UKF) frameworks, achieving comparable accuracy to state-of-the-art algorithms while eliminating the influence of magnetic interference on pitch and roll angles.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Article
Optics
Yiran Wang, Yu Ji, Xuyang Zhou, Xiu Wen, Yutong Li, Zhengjun Liu, Shutian Liu
Summary: This work presents a new reconstruction framework for structured illumination microscopy (SIM), which only requires four raw images and avoids extensive iterative computation. By using checkerboard pattern illumination modulation instead of sinusoidal fringe illumination, the proposed method significantly reduces image acquisition time and achieves higher image reconstruction rate. Additionally, the reconstruction process is non-iterative and not limited by the field of view size.
OPTICS AND LASERS IN ENGINEERING
(2024)