The TiSiN-Ag coatings were deposited on 304 stainless steel by multi-arc ion plating. The composition and structure of the coating were characterized by scanning electron microcopy, X-ray ...diffraction, X-ray photoelectron spectroscopy and transmission electron microscope, respectively. The hardness was tested using nanoindentation. The tribological behavior of the coating was investigated at room temperature, 350 °C, 550 °C and 750 °C, respectively. Ag presented as the nanosize clusters and metallic silver, and they were embedded in amorphous Si
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and nanocrystalline TiN. The results show that the TiSiN-Ag coating containing Ag concentration (~ 8.66 at.%) has the excellent frictional behaviors in the high temperature (> 550 °C), which is correlated with the diffusion of metallic Ag and the formed oxidation. Temperature plays a crucial role to drive the silver lubrication.
Low‐cost and environment‐friendly dual‐ion batteries (DIBs) with fast‐charging characteristics facilitate the development of high‐power energy storage devices. However, the incompatibility between ...the cathode and electrolyte at high voltage results in low Coulombic efficiency (CE) and short lifespan. Here, the addition of ≈0.5 wt% lithium difluoro(oxalate) borate salt into the electrolyte forms a robust and durable cathode–electrolyte interface (CEI) in situ on the graphite surface, which enables remarkable cycling of the graphite||Li battery with 87.5% capacity retention after 4000 cycles at 5 C and ultrafast rate capability with 88.8% capacity retention under 40 C (4 A g−1), delivering high‐power of 0.4–18.8 kW kg−1 at energy densities of 422.7–318.8 Wh kg−1. Taking advantage of this robust CEI, a graphite||graphite full battery demonstrates high reversible capacities of 97.6, 92.8, 88.7, and 85.4 mAh (g cathode)−1 at current rates of 10, 20, 30, and 40 C, respectively. The full battery also shows a long cycling life of over 6500 cycles with 92.4% capacity retention and an average CE of ≈99.4% at 1 A g−1, which is superior to other dual‐graphite (carbon) batteries in the literature. This work offers an effective interface‐stabilizing strategy on protecting graphite cathodes and a promising approach for developing DIBs with high‐power capability.
A robust and durable cathode‐electrolyte interface layer is constructed on the graphite surface in situ with a lithium difluoro(oxalate) borate salt additive, enabling the graphite||graphite full battery to give a superb power capability up to 50 C and a long cycling life over 6500 cycles with 92.4% capacity retention and an average Coulombic efficiency of ≈99.4%.
Hardness, elastic modulus and schematic diagram of nanocomposite TiSiN-Ag coatings design for microstructure, and hardness map. The scale bar of harness map is in GPa.
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•TiSiN-Ag ...coatings with different silver contents were synthesized by arc ion plating.•The coatings exhibit nanocrystallite and amorphous nc-TiN/nc-Ag/a-Si3N4 composite structure.•TiSiN-Ag coatings (5.3–7.9at.% Ag) exhibit higher hardness, lower COF and wear rate.
TiSiN-Ag nanocomposite coatings with different Ag contents were deposited on Ti–6Al–4V using reactive co-sputtering in multi-arc ion plating system. Influence of Ag contents on structure and tribological properties of TiSiN-Ag nanocomposite coatings was investigated. The TiSiN-Ag coatings were found to have unique nanocomposite structures composed of nanocrystallite and amorphous nc-TiN/nc-Ag/a-Si3N4. When the silver content was 1.4at.%, the coating exhibited high hardness (36GPa), but poor wear resistance. When the silver content was increased from 5.3 to 8.7at.%, the coatings possessed homogeneous distribution and small variation in hardness. Although these coatings revealed obvious decrease in hardness, significantly reduced in the friction coefficient and possessed excellent tribological properties, besides, the coating with the Ag content of 5.3at.% showed best wear resistance in artificial seawater and the coating (7.9at.% Ag) revealed the best wear resistance in ambient air. However, with a further increased incorporation of Ag into the TiSiN-Ag coating (17.0at.%) resulted in the formation of a large volume fraction of metallic silver, which caused a decrease both in hardness and wear resistance. The coating containing highest Ag concentration (21.0at.%) exhibited low friction coefficient both in ambient air and artificial seawater, although possessing low hardness.
Quantitative analysis of error sources in wave measurement intercomparison under real-world conditions remains challenging due to various factors such as spatial and temporal offsets in the field, ...diverse configurations of wave sensors and platforms, and distinct measurement algorithms. This study introduces a modified error analysis method based on sampling variability. Measurements from two co-deployed Datawell Waverider buoys at the National Marine Test Site (Weihai) in China offer an opportunity to assess the spatial variability error. The results reveal that for non-directional wave parameters, like significant wave height and mean zero-crossing period, the wave conditions in the field can be considered stationary, with random errors primarily arising from inherent sampling variability. Spatial offsets significantly impact directional wave parameters at peak frequencies, with large deviations (greater than 20°) in peak wave direction primarily attributed to bimodal distribution. For data with significant wave heights exceeding 0.5 m, random errors in the mean wave direction at the same frequency can be mainly attributed to sampling variability. The bulk directional wave parameters weighted by the energy spectrum demonstrate lower sensitivity to spatial offsets, and there is excellent agreement between the bulk mean directions when considering only the unimodal distribution data.
•Wave intercomparison of two co-deployed Datawell Waverider buoys was analyzed.•Random error of non-directional parameters mainly arises from sampling variability.•The directional wave parameters at peak frequencies are sensitive to spatial offsets.•Excellent agreement between the bulk mean direction of unimodal distribution data.
The TiSiCN coatings deposited at different bias voltages were fabricated on Ti6Al4V alloy by arc ion plating. The structure and properties of the TiSiCN coating were characterized using scanning ...electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, nanoindentation, potentiostat and ball-on-plate wear tests. As the bias voltage increases, the TiSiCN coating shows a nanocrystallite/amorphous structure, whereas the phase constitution and grain size changed slightly, and its hardness and tribocorrosion properties also change correspondingly. When the bias voltage is −100V, the coating has a composite structure of typical nanocrystallite/amorphous, and a small amount of MAX phase of Ti3SiC2. Moreover, the protection potential applied on the coating effectively prevents the electrochemical corrosion of the coating. However, the applied protection potential will accelerate the degradation of the coating when the channel formed between the surface of the wear track and substrate.
•A nanocrystallite/amorphous and Ti3SiC2 MAX phase nanostructure was found in TiSiCN coating.•The TiSiCN coating deposited at −100V exhibits the best tribocorrosion properties.•The synergistic effect of mechanical wear and electrochemical corrosion degraded coating.•The applied protection potential has both beneficial and harmful effects on coating.
The dual‐ion battery (DIB) is a promising energy storage system that demonstrates high‐power characteristics and fast‐charging capability. However, conventional electrolytes are not compatible with ...the high‐voltage graphite cathode and the reactive Li metal anode, thus leading to the poor cycle stability and low Coulombic efficiency of the DIB. Here, an all‐fluorinated electrolyte is reported that can enable a highly stable operation of the graphite||Li DIB up to 5.2 V by forming robust and less‐resistive passivation films on both electrodes to reduce side reactions. The electrolyte allows reversible PF6– anion insertion/extraction and Li+ cation plating/stripping in the graphite||Li battery, achieving stable cycling with 94.5% capacity retention over 5000 cycles at 500 mA g–1, high capacity utilization of 91.8% of the available charge capacity at 50 C (5000 mA g–1), and also minimal self‐discharge. At a low temperature of 0 °C, this all‐fluorinated electrolyte exhibits 97.8% of the room temperature reversible capacity, along with ≈100% capacity retention after more than 3000 cycles, at 5 C. This work sheds a new light on the development of fluorinated electrolytes for high voltage and long‐lasting DIBs.
An all‐fluorinated electrolyte enables reversible PF6– insertion/extraction in a high‐voltage cathode (5.2 V) and Li+ plating/stripping on a reactive Li metal anode. The graphite||Li battery demonstrates stable cycling with 94.5% capacity retention over 5000 cycles, no capacity fading upon 3000 cycles at 0 °C, ultrafast charging capability up to 50 C (5000 mA g–1) with 91.8% capacity utilization and a low self‐discharge rate.
The TiSiN/Ag multilayer coatings with fixed TiSiN layer thickness and different individual Ag layer thicknesses were prepared by arc ion plating. Quantification of mechanical response of TiSiN/Ag ...multilayer coatings through uniaxial micropillar compression tests was carried out to identify the elastic modulus, fracture strength, deformation and failure mechanism. The deformation and failure behavior of the micropillars assessed by direct scanning electron microscopy observation after the uniaxial compression tests revealed a linear increase of stress with strain up to a fracture point for all 1-μm micropillars, indicating an elastic response with brittle failure. In addition, in-situ micro-compression was carried out mainly on the micropillars with diameters of 600 nm and 300 nm; the stress-strain curves show an initial linear elastic response until the yield point was reached, followed by plastic deformation with a total strain of 27.99% and 42.7%, respectively. Moreover, size effect was also found in the micropillar compressions in which, the 300-nm micropillar showed the highest fracture strength of 16.71 ± 0.63 GPa.
•Quantification of mechanical response of TiSiN/Ag multilayer coatings through uniaxial micropillar compression tests.•In-situ micro-compression test for 600-nm and 300-nm micropillars.•Size defect was found in the micropillar compressions.•The 300-nm micropillar showed the highest fracture strength of 16.71 ± 0.63 GPa.
The TiSiN/Ag multilayer coatings with bilayer periods of ~50, 65, 80, 115, 150, and 410 nm have been deposited on Ti6Al4 V alloy by arc ion plating. In order to improve the adhesion of the TiSiN/Ag ...multilayer coatings, TiN buffer layer was first deposited on titanium alloy. The multi-interfacial TiSiN/Ag layers possess alternating TiSiN and Ag layers. The TiSiN layers display a typical nanocrystalline/amorphous microstructure, with nanocrystalline TiN and amorphous Si
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. TiN nanocrystallites embed in amorphous Si
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matrix exhibiting a fine-grained crystalline structure. The Ag layers exhibit ductile nanocrystalline metallic silver. The coatings appear to be a strong TiN (200)-preferred orientation for fiber texture growth. Moreover, the grain size of TiN decreases with the decrease of the bilayer periods. Evidence concluded from transmission electron microscopy revealed that multi-interfacial structures effectively limit continuous growth of single (200)-preferred orientation coarse columnar TiN crystals. The hardness of the coatings increases with the decreasing bilayer periods. Multi-interface can act as a lubricant, effectively hinder the cracks propagation and prevent aggressive seawater from permeating to substrate through the micro-pores to some extent, reducing the friction coefficient and wear rates. It was found that the TiSiN/Ag multilayer coating with a bilayer period of 50 nm shows an excellent wear resistance due to the fine grain size, high hardness, and silver-lubricated transfer films formed during wear tests.
•W microwires with designed microstructure were microfabricated under EBSD guidance.•High-density dislocations were introduced in W with reduced grain boundaries.•Ultrahigh strength and ductility ...were achieved in engineered W microwires.•The motion of pre-existing high-density dislocations produces high ductility of W.
Despite being strong with many outstanding physical properties, tungsten is inherently brittle at room temperature, restricting its structural and functional applications at small scales. Here, a facile strategy has been adopted, to introduce high-density dislocations while reducing grain boundaries, through electron backscatter diffraction (EBSD)-guided microfabrication of cold-drawn bulk tungsten wires. The designed tungsten microwire attains an ultralarge uniform tensile elongation of ~10.6%, while retains a high yield strength of ~2.4 GPa. in situ TEM tensile testing reveals that the large uniform elongation of tungsten microwires originates from the motion of pre-existing high-density dislocations, while the subsequent ductile fracture is attributed to crack-tip plasticity and the inhibition of grain boundary cracking. This work demonstrates the application potential of tungsten microcomponents with superior ductility and workability for micro/nanoscale mechanical, electronic, and energy systems.
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TiSiN-Ag coatings were prepared by arc ion plating on Ti6Al4V at 450 °C. The as-deposited coatings were then annealed in a vacuum at 550, 650 and 750 °C for 30 min respectively to observe the Ag ...morphology and distribution in TiSiN coating. The microstructure evolution of the TiSiN-Ag coatings was characterized through scanning electron microscopy (SEM), revealing the segregation of Ag on the coating surface. The TiSiN-Ag coating annealed at 750 °C has denser structure, and more nanoscale to m-size Ag outgrowths on the coating surface. The TiSiN-Ag coating annealed at 750 °C showed the highest hardness of 18.3 1.5 GPa and maximum ratios H/E and H3/E*2, with excellent mechanical properties. For the annealed TiSiN-Ag coatings, the friction coefficient is relatively low, and the TiSiN-Ag coating annealed at 750 °C has the lowest wear rate.
