Xuyang Zhou
@mpie.de
Max-Planck-Institut fuer Eisenforschung GmbH
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Xinren Chen, Xuyang Zhou, Frédéric De Geuser, Alisson Kwiatkowski da Silva, Huan Zhao, Eric Woods, Chuanlai Liu, Dirk Ponge, Baptiste Gault, and Dierk Raabe
Elsevier BV
Zhenhua Wang, Junhao Yuan, Qing Wang, Zhen Li, Xuyang Zhou, Junhua Luan, Jing Wang, Shijian Zheng, Zengbao Jiao, Chuang Dong,et al.
Elsevier BV
Mohamed N. Elkot, Binhan Sun, Xuyang Zhou, Dirk Ponge, and Dierk Raabe
Informa UK Limited
The precipitation of grain boundary (GB) κ-carbides critically influences the damage-tolerance ability of high-Mn high-Al lightweight steels, particularly in harsh environments (cryogenic and H environments). The formation and growth behavior of these carbides thus need to be understood. In this work, we use atom probe tomography and four-dimensional scanning transmission electron microscopy to study the formation mechanisms of GB κ-carbides in a Fe-28Mn-8Al-1.3C (wt.%) steel that is aged at 550°C, a temperature at which GB κ-carbide formation is often believed to be delayed or avoided. We observe that the formation of GB κ-carbides results from spinodal decomposition of grain interior (GI) κ-carbides and their further interaction with GB planes rather than from heterogeneous GB nucleation, as has been formerly proposed. However, the subsequent growth of GB κ-carbides shows different kinetics in comparison to GI κ-carbides. The underlying reason and its implications for future microstructure design of such steels are discussed. GRAPHICAL ABSTRACT IMPACT STATEMENT We originally report that grain boundary κ-carbides can result from spinodal decomposition rather than conventional heterogeneous nucleation and refute the possibility of avoiding their precipitation by controlling aging parameters.
Yue Li, Ye Wei, Zhangwei Wang, Xiaochun Liu, Timoteo Colnaghi, Liuliu Han, Ziyuan Rao, Xuyang Zhou, Liam Huber, Raynol Dsouza,et al.
Springer Science and Business Media LLC
AbstractChemical short-range order (CSRO) refers to atoms of specific elements self-organising within a disordered crystalline matrix to form particular atomic neighbourhoods. CSRO is typically characterized indirectly, using volume-averaged or through projection microscopy techniques that fail to capture the three-dimensional atomistic architectures. Here, we present a machine-learning enhanced approach to break the inherent resolution limits of atom probe tomography enabling three-dimensional imaging of multiple CSROs. We showcase our approach by addressing a long-standing question encountered in body-centred-cubic Fe-Al alloys that see anomalous property changes upon heat treatment. We use it to evidence non-statistical B2-CSRO instead of the generally-expected D03-CSRO. We introduce quantitative correlations among annealing temperature, CSRO, and nano-hardness and electrical resistivity. Our approach is further validated on modified D03-CSRO detected in Fe-Ga. The proposed strategy can be generally employed to investigate short/medium/long-range ordering phenomena in different materials and help design future high-performance materials.
Martí López Freixes, Xuyang Zhou, Raquel Aymerich-Armengol, Miquel Vega-Paredes, Lionel Peguet, Timothy Warner, and Baptiste Gault
Elsevier BV
Xuyang Zhou, Ali Ahmadian, Baptiste Gault, Colin Ophus, Christian H. Liebscher, Gerhard Dehm, and Dierk Raabe
Springer Science and Business Media LLC
AbstractGrain boundaries, the two-dimensional defects between differently oriented crystals, tend to preferentially attract solutes for segregation. Solute segregation has a significant effect on the mechanical and transport properties of materials. At the atomic level, however, the interplay of structure and composition of grain boundaries remains elusive, especially with respect to light interstitial solutes like B and C. Here, we use Fe alloyed with B and C to exploit the strong interdependence of interface structure and chemistry via charge-density imaging and atom probe tomography methods. Direct imaging and quantifying of light interstitial solutes at grain boundaries provide insight into decoration tendencies governed by atomic motifs. We find that even a change in the inclination of the grain boundary plane with identical misorientation impacts grain boundary composition and atomic arrangement. Thus, it is the smallest structural hierarchical level, the atomic motifs, that controls the most important chemical properties of the grain boundaries. This insight not only closes a missing link between the structure and chemical composition of such defects but also enables the targeted design and passivation of the chemical state of grain boundaries to free them from their role as entry gates for corrosion, hydrogen embrittlement, or mechanical failure.
Chaohua Zhang, Qiangwen Lai, Wu Wang, Xuyang Zhou, Kailiang Lan, Lipeng Hu, Bowen Cai, Matthias Wuttig, Jiaqing He, Fusheng Liu,et al.
Wiley
AbstractBi2Te3‐based alloys have great market demand in miniaturized thermoelectric (TE) devices for solid‐state refrigeration and power generation. However, their poor mechanical properties increase the fabrication cost and decrease the service durability. Here, this work reports on strengthened mechanical robustness in Bi2Te3‐based alloys due to thermodynamic Gibbs adsorption and kinetic Zener pinning at grain boundaries enabled by MgB2 decomposition. These effects result in much‐refined grain size and twofold enhancement of the compressive strength and Vickers hardness in (Bi0.5Sb1.5Te3)0.97(MgB2)0.03 compared with that of traditional powder‐metallurgy‐derived Bi0.5Sb1.5Te3. High mechanical properties enable excellent cutting machinability in the MgB2‐added samples, showing no missing corners or cracks. Moreover, adding MgB2 facilitates the simultaneous optimization of electron and phonon transport for enhancing the TE figure of merit (ZT). By further optimizing the Bi/Sb ratio, the sample (Bi0.4Sb1.6Te3)0.97(MgB2)0.03 shows a maximum ZT of ≈1.3 at 350 K and an average ZT of 1.1 within 300–473 K. As a consequence, robust TE devices with an energy conversion efficiency of 4.2% at a temperature difference of 215 K are fabricated. This work paves a new way for enhancing the machinability and durability of TE materials, which is especially promising for miniature devices.
Stoichko Antonov, T.S. Prithiv, Xuyang Zhou, Andrew Peterson, Baptiste Gault, and Ian Baker
Elsevier BV
Xinren Chen, Jaber Rezaei Mianroodi, Chuanlai Liu, Xuyang Zhou, Dirk Ponge, Baptiste Gault, Bob Svendsen, and Dierk Raabe
Elsevier BV
Ali Ahmadian, Daniel Scheiber, Xuyang Zhou, Baptiste Gault, Lorenz Romaner, Reza D. Kamachali, Werner Ecker, Gerhard Dehm, and Christian H. Liebscher
Wiley
The embrittlement of metallic alloys by liquid metals leads to catastrophic material failure and severely impacts their structural integrity. The weakening of grain boundaries by the ingress of liquid metal and preceding segregation in the solid are thought to promote early fracture. However, the potential of balancing between the segregation of cohesion-enhancing interstitial solutes and embrittling elements inducing grain boundary decohesion is not understood. Here, we unveil the mechanisms of how boron segregation mitigates the detrimental effects of the prime embrittler, zinc, in a Σ5 [0 0 1] tilt grain boundary in α -Fe (4 at.% Al). Zinc forms nanoscale segregation patterns inducing structurally and compositionally complex grain boundary states. Ab-initio simulations reveal that boron hinders zinc segregation and compensates for the zinc induced loss in grain boundary cohesion. Our work sheds new light on how interstitial solutes intimately modify grain boundaries, thereby opening pathways to use them as dopants for preventing disastrous material failure. This article is protected by copyright. All rights reserved.
Wei Luo, Zhuocheng Xie, Siyuan Zhang, Julien Guénolé, Pei‐Ling Sun, Arno Meingast, Amel Alhassan, Xuyang Zhou, Frank Stein, Laurent Pizzagalli,et al.
Wiley
Brittle topologically close-packed precipitates form in many advanced alloys. Due to their complex structures little is known about their plasticity. Here, we present a strategy to understand and tailor the deformability of these complex phases by considering the Nb-Co μ-phase as an archetypal material. The plasticity of the Nb-Co μ-phase is controlled by the Laves phase building block that forms parts of its unit cell. We find that between the bulk C15-NbCo2 Laves and Nb-Co μ-phase, the interplanar spacing and local stiffness of the Laves phase building block change, leading to a strong reduction in hardness and stiffness, as well as a transition from synchroshear to crystallographic slip. Furthermore, as the composition changes from Nb6 Co7 to Nb7 Co6 , the Co atoms in the triple layer are substituted such that the triple layer of the Laves phase building block becomes a slab of pure Nb, resulting in inhomogeneous changes in elasticity and a transition from crystallographic slip to a glide-and-shuffle mechanism. These findings open opportunities to purposefully tailor the plasticity of these topologically close-packed phases in the bulk by manipulating the interplanar spacing and local shear modulus of the fundamental crystal building blocks at the atomic scale. This article is protected by copyright. All rights reserved.
Hanna Bishara, Lena Langenohl, Xuyang Zhou, Baptiste Gault, James P. Best, and Gerhard Dehm
Elsevier BV
Se-Ho Kim, Kihyun Shin, Xuyang Zhou, Chanwon Jung, Hyun You Kim, Stella Pedrazzini, Michele Conroy, Graeme Henkelman, and Baptiste Gault
Elsevier BV
Xuyang Zhou, Yang Bai, Ayman A. El-Zoka, Se-Ho Kim, Yan Ma, Christian H. Liebscher, Baptiste Gault, Jaber R. Mianroodi, Gerhard Dehm, and Dierk Raabe
American Physical Society (APS)
When solid-state redox-driven phase transformations are associated with mass loss, vacancies are produced that develop into pores. These pores can influence the kinetics of certain redox and phase transformation steps. We investigated the structural and chemical mechanisms in and at pores in a combined experimental-theoretical study, using the reduction of iron oxide by hydrogen as a model system. The redox product (water) accumulates inside the pores and shifts the local equilibrium at the already reduced material back towards re-oxidation into cubic-Fe1-xO (where x refers to Fe deficiency, space group Fm3-m). This effect helps to understand the sluggish reduction of cubic-Fe1-xO by hydrogen, a key process for future sustainable steelmaking.
K.N. Sasidhar, Xuyang Zhou, Michael Rohwerder, and Dirk Ponge
Elsevier BV
Mahander P. Singh, Se-Ho Kim, Xuyang Zhou, Hiram Kwak, Alisson Kwiatkowski da Silva, Stoichko Antonov, Leonardo Shoji Aota, Chanwon Jung, Yoon Seok Jung, and Baptiste Gault
Wiley
Layered LiMO2 (M = Ni, Co, Mn, and Al mixture) cathode materials used for Li‐ion batteries are reputed to be highly reactive through their surface, where the chemistry changes rapidly when exposed to ambient air. However, conventional electron/spectroscopy‐based techniques or thermogravimetric analysis fails to capture the underlying atom‐scale chemistry of vulnerable Li species. To study the evolution of the surface composition at the atomic scale, cryogenic atom probe tomography is used herein and the surface species formed during exposure of a LiNi0.8Mn0.1Co0.1O2 (NMC811) cathode material to air are probed. The compositional analysis evidences the formation of Li2CO3. Site‐specific examination from a cracked region of an NMC811 particle also reveals the predominant presence of Li2CO3. These insights will help to design improved protocols for cathode synthesis and cell assembly, as well as critical knowledge for cathode degradation.
Jiehua Li, Xuyang Zhou, Andrew Breen, Zirong Peng, Jing Su, Philipp Kürnsteiner, Maria Jazmin Duarte Correa, Marta Lipińska Chwałek, Huiyuan Wang, David Holec,et al.
Elsevier BV
Po-Yen Tung, Xuyang Zhou, Lutz Morsdorf, and Michael Herbig
Elsevier BV
Mohamed Naguib Elkot, Binhan Sun, Xuyang Zhou, Dirk Ponge, and Dierk Raabe
Elsevier BV
Martí López Freixes, Xuyang Zhou, Huan Zhao, Hélène Godin, Lionel Peguet, Timothy Warner, and Baptiste Gault
Springer Science and Business Media LLC
AbstractThe high-strength 7xxx series aluminium alloys can fulfil the need for light, high strength materials necessary to reduce carbon-emissions, and are extensively used in aerospace for weight reduction purposes. However, as all major high-strength materials, these alloys can be sensitive to stress-corrosion cracking (SCC) through anodic dissolution and hydrogen embrittlement (HE). Here, we study at the near-atomic-scale the intra- and inter-granular microstructure ahead and in the wake of a propagating SCC crack. Moving away from model alloys and non-industry standard tests, we perform a double cantilever beam (DCB) crack growth test on an engineering 7xxx Al-alloy. H is found segregated to planar arrays of dislocations and to grain boundaries that we can associate to the combined effects of hydrogen-enhanced localised plasticity (HELP) and hydrogen-enhanced decohesion (HEDE) mechanisms. We report on a Mg-rich amorphous hydroxide on the corroded crack surface and evidence of Mg-related diffusional processes leading to dissolution of the strengthening η-phase precipitates ahead of the crack.
Siyuan Zhang, Zhuocheng Xie, Philipp Keuter, Saba Ahmad, Lamya Abdellaoui, Xuyang Zhou, Niels Cautaerts, Benjamin Breitbach, Shamsa Aliramaji, Sandra Korte-Kerzel,et al.
Royal Society of Chemistry (RSC)
In a textured Mg thin film, two types of 〈0001〉 tilt grain boundaries are identified by electron microscopy and atomistic simulation. Coincidence site lattice and dislocation models are applied to study boundaries in hexagonal close-packed crystals.
Jiehua Li, Xuyang Zhou, Jing Su, Benjamin Breitbach, Marta Lipińska Chwałek, Huiyuan Wang, and Gerhard Dehm
Elsevier BV
Se-Ho Kim, Kang Dong, Huan Zhao, Ayman A. El-Zoka, Xuyang Zhou, Eric V. Woods, Finn Giuliani, Ingo Manke, Dierk Raabe, and Baptiste Gault
American Chemical Society (ACS)
To advance the understanding of the degradation of the liquid electrolyte and Si electrode, and their interface, we exploit the latest developments in cryo-atom probe tomography. We evidence Si anode corrosion from the decomposition of the Li salt before charge–discharge cycles even begin. Volume shrinkage during delithiation leads to the development of nanograins from recrystallization in regions left amorphous by the lithiation. The newly created grain boundaries facilitate pulverization of nanoscale Si fragments, and one is found floating in the electrolyte. P is segregated to these grain boundaries, which confirms the decomposition of the electrolyte. As structural defects are bound to assist the nucleation of Li-rich phases in subsequent lithiations and accelerate the electrolyte’s decomposition, these insights into the developed nanoscale microstructure interacting with the electrolyte contribute to understanding the self-catalyzed/accelerated degradation Si anodes and can inform new battery designs unaffected by these life-limiting factors.
Renelle Dubosq, David A. Schneider, Xuyang Zhou, Baptiste Gault, Brian Langelier, and Pia Pleše
Elsevier BV
Patrick Harrison, Xuyang Zhou, Saurabh Mohan Das, Pierre Lhuissier, Christian H. Liebscher, Michael Herbig, Wolfgang Ludwig, and Edgar F. Rauch
Elsevier BV