Structural materials

  • Article
    | Open Access

    Wear-resistant metals have long been a pursuit of reducing wear-related energy and material loss. Here the authors present the ‘reactive wear protection’ strategy via friction-induced in situ formation of strong and deformable oxide nanocomposites on a surface.

    • Chang Liu
    • , Zhiming Li
    •  & Dierk Raabe
  • Article
    | Open Access

    The strength in BCC high-entropy alloys is associated with the type of mobile dislocations. Here the authors demonstrate by means of an ample array of experimental techniques that edge dislocations can control the strength of BCC high-entropy alloys.

    • Chanho Lee
    • , Francesco Maresca
    •  & W. A. Curtin
  • Article
    | Open Access

    The inverse design of the material for given target property is challenging for glasses due to their disordered non-prototypical structure. Wang and Zhang propose a data-driven property oriented inverse approach for design of glassy materials with desired functionalities.

    • Qi Wang
    •  & Longfei Zhang
  • Article
    | Open Access

    The limited strength of green parts have been a major hurdle in the Binder Jet Additive Manufacturing. Here the authors apply polyethyleneimine binder to print silica sand structures with double the flexural strength of green parts and 8-fold increase in the strength upon reactive infiltration.

    • Dustin B. Gilmer
    • , Lu Han
    •  & Tomonori Saito
  • Article
    | Open Access

    The morphology of semicrystalline plastics on the 1-100 μm scale, such as spherulites, strongly affect mechanical and other properties of the material but currently only 2D imaging techniques are available. Here, the authors use fluorescence labels and confocal microscopy to visualize the internal structure of neat polymers and composites in 3D and reveal unsuspected morphologies.

    • Shu-Gui Yang
    • , Zhen-Zhen Wei
    •  & Goran Ungar
  • Article
    | Open Access

    The authors create synthetic dimensions in acoustic crystals composed of cavity arrays, strongly coupled through modulated channels. They provide evidence for 1D and 2D dynamic topological pumping, and show that the higher-order topological sound transport is robust against the geometrical imperfections.

    • Hui Chen
    • , Hongkuan Zhang
    •  & Guoliang Huang
  • Article
    | Open Access

    Refractory high entropy alloys hold big promise for elevated-temperature applications. Here the authors investigate the influence of short-range order on the mobility of dislocations in high-entropy alloys by large-scale molecular dynamics simulation based on a machine-learning interatomic potential.

    • Sheng Yin
    • , Yunxing Zuo
    •  & Robert O. Ritchie
  • Article
    | Open Access

    Precipitation hardening, used as an effective strengthening strategy in various alloy systems, has been usually achieved by coherent precipitates. Here, the authors develop ultrastrong ductile alloys employing structurally dissimilar semicoherent precipitates by shear band-driven precipitation.

    • Tae Jin Jang
    • , Won Seok Choi
    •  & Seok Su Sohn
  • Article
    | Open Access

    Conventional ultrafine grains can generate high-strength Mg alloys, but non-equilibrium grain boundaries deteriorates their corrosion resistance. Here, the authors present ultrafine grained Mg alloys with dense twins that display high strength and reduced corrosion rate by one order of magnitude.

    • Changjian Yan
    • , Yunchang Xin
    •  & Qing Liu
  • Article
    | Open Access

    Polycrystal-inspired architected materials are found to be high strength and damage tolerant. Here, the authors conduct in-depth work to unravel the mechanism responsible for the hardening phenomenon, in particular the role of polygrain-like boundary in the post-yield shear band activities.

    • Chen Liu
    • , Jedsada Lertthanasarn
    •  & Minh-Son Pham
  • Article
    | Open Access

    Advanced screening strategies for the design of high-entropy alloys are highly desirable. Here the authors use the project-oriented design strategy and CALPHAD-based high-throughput calculation tool to rapidly screen promising Al-Cr-Fe-Mn-Ti structural HEAs for high-temperature applications.

    • Rui Feng
    • , Chuan Zhang
    •  & Peter K. Liaw
  • Article
    | Open Access

    Glass is indispensable but its processing options are limited. Here the authors extend origami techniques to shaping three-dimensional transparent glass by introducing physical cavitation and chemical dynamic bond exchange in the pre-glass polymer-silica nanocomposites.

    • Yang Xu
    • , Ye Li
    •  & Tao Xie
  • Article
    | Open Access

    Upscale fabrication of functionalized microparticles is a pending challenge. Here, Kim et al. exploit the rheology of a thixotropic medium to grind sizeable amounts of raw material into well-defined colloidal dispersions, physically stabilized for further production steps.

    • Sang Yup Kim
    • , Shanliangzi Liu
    •  & Rebecca Kramer-Bottiglio
  • Article
    | Open Access

    The stacking fault energy is connected to the response of crystals to deformation. Here the authors report a computational study in a model NiCo system to demonstrate the key importance of the dislocation/solute interaction for the accurate assessment of stacking fault energy in alloys beyond dilute limit.

    • Mulaine Shih
    • , Jiashi Miao
    •  & Maryam Ghazisaeidi
  • Article
    | Open Access

    Spontaneous jumping of condensing droplets holds promise for antifogging, but is generally inhibited for microdroplets. Lecointre et al. show that antifogging ability of cone structures at nanoscales is universal over a large range of cone sizes, shapes, apex angles and even truncation.

    • Pierre Lecointre
    • , Sophia Laney
    •  & David Quéré
  • Article
    | Open Access

    Damage that occurs in second generation high-temperature-superconducting wires is problematic. Here, the authors present real-time magnetic flux behaviour in these wires under tensile strain and reveal damage evolution, including the amorphous phase in the superconducting layer acting in crack blunting during tension

    • You-He Zhou
    • , Cong Liu
    •  & Xingyi Zhang
  • Article
    | Open Access

    The reduction in thermal conductivity is usually achieved by increasing the scattering rate or localization of heat carriers. Here, the authors propose a mechanism to suppress the thermal transport in amorphous systems such as SiTe binary alloys via tailoring the cross-linking network between the atoms.

    • Kiumars Aryana
    • , Derek A. Stewart
    •  & Patrick E. Hopkins
  • Article
    | Open Access

    The competition between the formation of different phases and their kinetics need to be clearly understood to make materials with on-demand and multifaceted properties. Here, the authors reveal, by a combination of complementary in situ techniques, the mechanism of a Cu-Zr-Al metallic glass’s high propensity for metastable phase formation, which is partially through a kinetic mechanism of Al partitioning.

    • Jiri Orava
    • , Shanoob Balachandran
    •  & Ivan Kaban
  • Article
    | Open Access

    Bioinspired vascular networks transport heat and mass in multifunctional materials but lengthy multistep fabrication processes hinder large-scale application of structural vascular materials. Here, the authors report rapid, scalable, and synchronized fabrication of vascular thermosets and fiberreinforced composites under ambient conditions.

    • Mayank Garg
    • , Jia En Aw
    •  & Nancy R. Sottos
  • Article
    | Open Access

    Fragmentation of breaking glass as a brittle solid is a problem of equal practical and theoretical importance. Kooij et al. demonstrate that the fragment size distribution can surprisingly be both, either power-law or exponential, depending on how a particular specimen is broken.

    • Stefan Kooij
    • , Gerard van Dalen
    •  & Daniel Bonn
  • Article
    | Open Access

    The Janssen effect refers to the saturation of the apparent mass of a column of granular material, due to friction with the boundary of the column. Here, using ferromagnetic beads, Thorens et al. succeed in controlling the apparent mass of the column via an applied magnetic field.

    • L. Thorens
    • , K. J. Måløy
    •  & S. Santucci
  • Article
    | Open Access

    Osmotically assisted reverse osmosis can overcome limitations of the reverse osmosis process but a strong membrane which can withstand a high hydraulic pressure is crucial. Here, the authors develop strong polymer thin film composite hollow fiber membranes with exceptionally high hydraulic burst pressures of up to 110 bar, while maintaining high water permeance and salt rejection.

    • Can Zeng Liang
    • , Mohammad Askari
    •  & Tai-Shung Chung
  • Article
    | Open Access

    It is difficult to achieve high current density and long lifetime for micro generators owing to the common friction and wear. Here the authors invent a microscale Schottky superlubric generator to tackle this issue, reporting not only high current and power densities but also long lifetime of at least 5,000 cycles.

    • Xuanyu Huang
    • , Xiaojian Xiang
    •  & Quanshui Zheng
  • Article
    | Open Access

    High-temperature deformation of materials is challenging to evaluate. Here the authors develop a novel device that allows atomic resolved in situ high temperature mechanical tests inside a transmission electron microscope and reveal ductile fracture of a single crystal tungsten deformed at 973 K.

    • Jianfei Zhang
    • , Yurong Li
    •  & Xiaodong Han
  • Article
    | Open Access

    The relationship between the strain rate and micro-scale deformation in metals is still poorly understood. Here the authors use discrete dislocation dynamics and molecular dynamics to establish a universal relationship between material strength, dislocation density, strain rate and dislocation mobility in fcc metals.

    • Haidong Fan
    • , Qingyuan Wang
    •  & Michael Zaiser
  • Article
    | Open Access

    Switching mechanical properties in stiff bioinspired nanocomposites is challenging as they contain high fractions of hard reinforcements. Here, the authors demonstrate reversible electrical switching in highly-reinforced cellulose nanopapers using an applied low direct current.

    • Dejin Jiao
    • , Francisco Lossada
    •  & Andreas Walther
  • Article
    | Open Access

    Homojunctions are very promising in photocatalysis, but challenging to achieve. Herein, authors report a well-defined hierarchical metal–organic framework-based homojunction, formed via a one-pot synthesis route directed by hollow transition metal nanoparticles, as photocatalysts for CO2 reduction.

    • Yannan Liu
    • , Chuanshuang Chen
    •  & Dongling Ma
  • Article
    | Open Access

    Interactions of dislocations with coherent twin boundaries contribute to strength and ductility in metals, but investigating the interaction mechanisms is challenging. Here the authors unravel these mechanisms through quantitative in-situ transmission electron microscopy observations in nickel bi-crystal samples under tensile loading.

    • Vahid Samaee
    • , Maxime Dupraz
    •  & Hosni Idrissi
  • Article
    | Open Access

    Segregation of solute atoms at interfaces affects the properties of alloys and needs to be understood to allow their rational design. Here the authors report an unusual solute segregation phenomenon in a group of Mg alloys, driven by chemical bonding, where solute atoms larger than Mg segregate to compression sites of specific fully coherent twin boundary.

    • Cong He
    • , Zhiqiao Li
    •  & Jian-Feng Nie
  • Article
    | Open Access

    Crystal defects critically influence surface chemical reactions in nanomaterials, yet the basic mechanisms at play are still elusive. Here, the authors show the atomic-scale dynamics of surface oxidation at coherent planar defects in Ag and Pd, revealing how twins and stacking-faults selectively oxidize metallic nanocrystals.

    • Qi Zhu
    • , Zhiliang Pan
    •  & Jiangwei Wang
  • Article
    | Open Access

    The mobility of dislocation loops in materials is of key importance to understanding their deformation behavior. Here the authors using self-adaptive accelerated molecular dynamics show self-diffusion of <100> interstitial loops in body-centered cubic (BCC) iron by changing its habit plane as also confirmed by transmission electron microscopy (TEM) measurements.

    • N. Gao
    • , Z. W. Yao
    •  & F. Gao
  • Article
    | Open Access

    Predicting segregation energies of alloy systems can be challenging even for a single grain boundary. Here the authors propose a machine-learning framework, which maps the local environments on a distribution of segregation energies, to predict segregation energies of alloy elements in polycrystalline materials.

    • Malik Wagih
    • , Peter M. Larsen
    •  & Christopher A. Schuh
  • Article
    | Open Access

    Thermal metamaterials are able to produce unconventional physical properties. Here, the authors demonstrate a thermal metamaterial with conductivity that can be continuously tuned over a very large range.

    • Guoqiang Xu
    • , Kaichen Dong
    •  & Cheng-Wei Qiu
  • Article
    | Open Access

    Thermal drawing of glass-cladded metal nanowires is limited by fluid instabilities. Hwang et al. show how admixing tungsten carbide nanoparticles to the zinc core of a borosilicate-cladded wire leads to intact fibres over lengths significantly exceeding those of metals with high melting points.

    • Injoo Hwang
    • , Zeyi Guan
    •  & Xiaochun Li
  • Article
    | Open Access

    The authors investigate 3D-printed tips, based on controlled microstructural architectured materials, as probes for shear-mode atomic force microscopy. They demonstrate that the tailored stiffness and energy-absorbing behaviour of the material are beneficial for improving image quality.

    • Liangdong Sun
    • , Hongcheng Gu
    •  & Zhongze Gu
  • Article
    | Open Access

    Anomalous mechanical behaviors provide an opportunity to regulate the functions of materials. Here the authors show that materials with coexisting negative, zero and positive compressibilities can “squeeze” volume compressibility into one direction, and thus stabilize transmission processes under pressure.

    • Xingxing Jiang
    • , Maxim S. Molokeev
    •  & Zheshuai Lin
  • Article
    | Open Access

    It is desirable yet challenging to develop sustainable structural materials to replace petroleum-based plastics. Here, the authors report a facile assembly method for manufacturing high-performance structural materials with a unique combination of high strength, toughness and stiffness.

    • Qing-Fang Guan
    • , Huai-Bin Yang
    •  & Shu-Hong Yu
  • Article
    | Open Access

    The fatigue performance of high strength aluminum alloys is notoriously poor, leading to design limitations for transportation structures. Here the authors design microstructures to exploit the mechanical energy of fatigue to dynamically heal the microstructural weak points and improve the high cycle fatigue life.

    • Qi Zhang
    • , Yuman Zhu
    •  & Christopher Hutchinson