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In this paper, the ultrasonic spray pyrolysis (USP) technology, under normal pressure conditions was adopts in this study to deposited ZnO films. The cheap zinc acetate, ammonium fluoride, and gallium chloride was used as Zn source, F source, Ga source and Cl source, respectively for deposited F, Cl, Al and Ga co-doped ZnO (FCAGZO) films. The influence of substrate temperature (Ts) on the morphology, structure, optical and electrical properties of ZnO thin films was studied. X-ray diffraction analysis shows that the Ts does not change the crystal structure of the ZnO film, and all films have a hexagonal wurtzite structure. With increase of Ts only the preferred orientation of the film changes from (1 0 0) to (0 0 2). X-ray photoelectron spectroscopy further confirmed the successful doping of ZnO by F, Cl, Al, and Ga, which accounts for the enhancement in carrier concentration in the FCAGZO films over that of pristine ZnO. As Ts increases, the resistivity first decreases, and then gradually increases. When the optimal substrate temperature Ts = 400 °C, the prepared FCAGZO film has a resistivity of 1.47 × 10-3 Ωcm when rapid heat treatment in N2 atmosphere at 750 °C, and the average transmittance exceeds 85% in the range of 400–1400 nm.

(85-x)WC–15 wt%Al2O3–xTiC (x = 0, 1.5, 2.5, 5, 10, and 20 wt%) composites were prepared by vacuum hot-press sintering. The influence of TiC addition on the corrosion behaviour of WC–Al2O3 composites in 0.1 M NaOH solution was revealed. The results suggest that all the samples containing added TiC had the TiC phase and (W, Ti) C solid-solution phase, while the base composite had neither phase. With increasing added TiC content, the average grain size of WC decreased, and the relative density first increased and then decreased. Furthermore, the results suggest that the addition of TiC could noticeably increase the free corrosion potential and impedance and reduce the corrosion current density. However, the composite containing 20 wt% added TiC showed the opposite trend. Therefore, it can be concluded that the corrosion performance of the composites in an alkaline medium can be improved by adding an appropriate amount of TiC. The change in corrosion properties was caused by changes in the solid-solution phase, relative density, and TiO2 oxide film.

Dual-phase metallic glasses (DP-MGs), a special member of the MGs family, often reveal unusual strength and ductility, yet, their corrosion behaviors are not understood. Here, we developed a nanostructured Mg57Zn36Ca7 (at.%) DP-MG and uncovered its corrosion mechanism in simulated body fluid (SBF) at the near-atomic scale utilizing transmission electron microscope (TEM) and atom probe tomography (APT). The 10-nm-wide Ca-rich amorphous phases allow oxygen propagation into the DP-MG, resulting in a micrometer thick hydroxides/oxides layer. This dense corrosion layer protects the DP-MG from further corrosion, enabling a corrosion rate that is 77% lower than that of Mg (99.99% purity).

Photogating and electrical gating are key physical mechanisms in organic phototransistors (OPTs). However, most OPTs are based on thick and polycrystalline films, which leads to substantially low efficiency of both photogating and electrical gating and thus reduced photoresponse. Herein, high-performance OPTs based on few-layered organic single-crystalline heterojunctions are proposed and the obstacle of thick and polycrystalline films for photodetection is overcome. Because of the molecular scale thickness of the type I organic single-crystalline heterojunctions in OPTs, both photogating and electrical gating are highly efficient. By synergy of efficient photogating and electrical gating, key figures of merit of OPTs reach the highest among those based on planar heterojunctions so far as we know. The production of few-layered organic single-crystalline heterojunctions will provide a new type of advanced materials for various applications.

Deuteration of hydrogen-bonded phase transition crystals can increase the transition temperatures due to the isotope effect. But rare examples show the opposite trend that originates from the structural changes of the hydrogen bond, known as the geometric H/D isotope effect. Herein, we report an organic crystal, diethylammonium hydrogen 1,4-terephthalate, exhibits a reversible structural phase transition and dielectric switching. Structural study shows the cations reside in channels formed by one-dimensional hydrogen-bonded anionic chains and undergo an order-disorder transition at around 206 K. The deuterated counterpart shows an elongation of the O···O hydrogen bond by about 0.005 A. This geometric isotope effect releases the internal pressure of the anionic host on the cation guests and results in a downward shift of the phase transition temperature by 10 K.

Mechano-electro-chemical coupling during the ion diffusion process is a core factor to determine the electrochemical performance of electrodes. However, relationship between the mechanics and the electrochemistry has not been clarified by experiments. In this work, we conduct an in situ, visual, comprehensive characterization of strain field and Li concentration distribution to further explore the mechano-electro-chemical relationship. The digital image correlation characterized by fluorescent speckle and active optical imaging is developed. Combined with electrochromic-based Li concentration detection, the spatiotemporal evolution of in-plane strain and Li concentration of a graphite electrode during the lithiation and delithiation processes are measured and displayed visually via a dual optical path acquisition system. The visual results show that in-plane strain and Li concentration possess a spatially non-uniform gradient distribution along the radial direction (i.e., diffusion path) with large values outside and small values inside, and that both present obvious temporal segmentation. And mechano-electro-chemical coupling analysis reveals that the in-plane strain is not always linearly related to the concentration and infers that a high strain limits the diffusion and lithiation. The strain–concentration evolution exhibits obvious asymmetric differences between lithiation and delithiation, wherein three equations are fitted to approximately represent the evolution process between in-plane strain and concentration during the lithiation and delithiation processes This work overcomes the difficulties of fine strain measurements and collaborative concentration characterization during the electrochemical process, and provides an effective experimental method and data support for further exploration of mechano-electro-chemical coupling.

The variation of the morphology and distribution of cementite particles in different prior structures with spheroidizing annealing process has been proceeded in this paper. It is found that the dissolution and coarsening progresses of various initial structures in spheroidizing annealing process are quite asynchronous due to the different interlamellar spacing. The dissolution rate of degenerated pearlite (D-P) with finer interlamellar spacing is faster. The granular cementite in the spheroidized microstructure is fine, uniform and dense. The mean diameter of spherical cementite is refined to 233 nm. However, the initial structure of degenerated pearlite (D-P) is highly sensitive to the austenitization temperature. The cementite is easy to be coarsened under high austenitizing temperature. The coarsening is accompanied by the gradual increase of the Cr content in the cementite, which increases the stability of the cementite. Therefore, the optimal austenitizing temperature for degenerated pearlite (D-P) is suggested to be 770 °C. The dissolution rates of cementite in spheroidized structures are related to the initial pearlite interlamellar spacing and the austenitizing temperature. A detailed experimental research and analysis are needed on the evolution of different initial structures during spheroidizing annealing treatment.

Formic acid intercalated Mg-Al layered double hydroxide (Mg-Al Fo-LDH) was prepared by calcination reduction intercalation assembly technology. The structure of the deicing additive was characterized by fourier transform infrared (FTIR) and X-ray diffraction (XRD). The freezing point of aqueous solution with different quality of deicing additive and the surface freezing point and adhesion of asphalt mixture were tested. The results show that formic acid ion has been intercalated into the interlayer of Mg-Al layered double hydroxide by FTIR and XRD patterns. The freezing point of 5wt% Mg-Al Fo-LDH aqueous solution reaches -9.32 °C, while the surface freezing point of the asphalt mixture mixed with 5wt% Mg-Al Fo-LDH is -6.5°C. At -8 °C, the adhesion force of the surface ice layer is 78.4N, and after the asphalt mixture is soaked in water, the surface freezing point and adhesion force of the ice layer do not change.

SBS modified bitumen membrane used in underground engineering and coastal buildings would be corroded by chemical media, which greatly influenced the service life of waterproofing membranes. In this paper, SBS modified bitumen (MB), SBS modified bitumen with stone powder (MBS) and SBS modified bitumen with talc powder (MBT) were corroded by acidic, alkaline, and saline solutions for different time to evaluated the effect of chemical corrosion on the properties of SBS modified bitumen waterproofing membrane. The mass change ratio, low temperature flexibility, softening point and viscosity of SBS modified bitumen were investigated, and Fourier infrared spectroscopy (FTIR) was used to analyze the chemical structural changes of SBS modified bitumen after corrosion. The results showed that the mass of SBS modified bitumen decreased, the low temperature performance decreased, and the softening point increased after corrosion by chemical solutions. The influence of acidic and saline solution was more serious on SBS modified bitumen with fillers, and the properties of MBS has greatest degradation in acidic solution compared with MB and MBT. In alkaline solution, the properties degradation of MBT and MBS was less than that of MB, which indicated that filler could inhibit the alkaline corrosion of SBS modified bitumen. FTIR showed that C=C decreased more in acidic solution, while C=O and S=O of SBS modified bitumen increased significantly after alkaline solution corrosion, which indicated that acidic solution corrosion easily caused SBS degradation, while alkaline solution corrosion was easy to oxidize SBS and bitumen.

Recrystallization has been a major method to induce heterogeneous grain structure for improving the strength–ductility combination of single-phase high-entropy alloys (HEAs). However, the recrystallization kinetics, which are the guideline for controlling the recrystallization behavior, of single-phase HEAs are relatively less explored. Here, we uncover the recrystallization behaviors of typical single-phase NiCoCrFe and Ni2CoCrFe HEAs. Our results showed that the two investigated HEAs exhibit almost similar recrystallization activation energy around 230 kJ·mol−1, but distinctively different recrystallization kinetics. This abnormal difference is attributed to the deformation twins of NiCoCrFe. These findings indicate that, except for textbook factors, deformation twinning significantly enhances the recrystallization behavior of HEAs.

The distribution of welding residual stress is the basis of controlling environmental cracking failure in the joint area of steel pipeline. In this study, 3D actual-size finite element models were developed for X80 steel pipe to predict the welding stress field in four typical girth joints. Electrochemical measurements under multi-stage loading revealed the relationship among tensile stress level, dislocation multiplication, and corrosion. The increased number of weld passes reduced the peak residual stress, and the adopted fully automatic welding decreased the high-stress zone where dislocation multiplication might occur. Therefore, adopting automatic welding and moderately increasing the number of weld passes are recommended to control welding residual stress.

Precipitation-hardened high entropy alloys (HEAs) with carefully tuned compositions have shown excellent mechanical properties, demonstrating great potential for engineering applications. However, due to the lack of precise multiple phase diagrams, the composition design of multi-principal-component HEAs still inevitably relies on the extremely time-consuming trial-and-error approach. The present study, on the basis of powerful composition quantification ability of atom probe tomography (APT) technology, proposed a framework to guide the quantitative design of precipitation-hardened HEAs. In this framework, the elemental partitioning was used as a crucial route to avoid the thermodynamic challenge of designing precipitation-hardened HEAs. As a case study, the role of Ti/Al ratio in the design of γ-γ′ HEAs was predicted through the proposed framework and then validated by experimental studies. The framework predicted that when the total content of Ti and Al is fixed, a higher Ti/Al ratio makes γ-γ′ HEA stronger. APT and mechanical results agreed well with these predictions and validated the feasibility of the framework. These findings provided a new route to design the precipitation-hardened alloys and a deeper insight into the design of γ-γ′ HEA.

The multi-principal-component concept of high-entropy alloys (HEAs) generates numerous new alloys. Among them, nanoscale precipitated HEAs have achieved superior mechanical properties and shown the potentials for structural applications. However, it is still a great challenge to find the optimal alloy within the numerous candidates. Up to now, the reported nanoprecipitated HEAs are mainly designed by a trial-and-error approach with the aid of phase diagram calculations, limiting the development of structural HEAs. In the current work, a novel method is proposed to accelerate the development of ultra-strong nanoprecipitated HEAs. With the guidance of physical metallurgy, the volume fraction of the required nanoprecipitates is designed from a machine learning of big data with thermodynamic foundation while the morphology of precipitates is kinetically tailored by prestrain aging. As a proof-of-principle study, an HEA with superior strength and ductility has been designed and systematically investigated. The newly developed γ′-strengthened HEA exhibits 1.31 GPa yield strength, 1.65 GPa ultimate tensile strength, and 15% tensile elongation. Atom probe tomography and transmission electron microscope characterizations reveal the well-controlled high γ′ volume fraction (52%) and refined precipitate size (19 nm). The refinement of nanoprecipitates originates from the accelerated nucleation of the γ′ phase by prestrain aging. A deeper understanding of the excellent mechanical properties is illustrated from the aspect of strengthening mechanisms. Finally, the versatility of the current design strategy to other precipitation-hardened alloys is discussed.

Thermal conductivity of polymers gains much attention in many fields, and the formation of a heat conduction network is very important for polymer coatings. Carbon nanofiller is one type of excellent candidate fillers for improving thermal conductivity, but the poor incorporation between the filler and the polymer restricts coating performances. In this study, the heat transfer oil (HTO) was used as a medium to communicate the carbon nanofiller with the polymer (poly(vinylidene fluoride) (PVDF), fluorinated ethylene propylene (FEP)) and to improve the thermal conductivity and corrosion resistance of PVDF composite coatings. The micronanostructure of superhydrophobic PVDF/FEP/SiO2 (modified PVDF or m-PVDF) composite coatings was used as a storage space for the HTO, so that various carbon nanofiller including carbon nanotubes (CNTs), graphene, carbon black, and carbon nanofibers can take effect in improving thermal conductivity. Among the m-PVDF/carbon nanofiller composite coatings, the HTO/m-PVDF/CNTs coating gained the highest thermal conductivity of 0.53 W·m−1·K−1 after HTO modification, which was 3.3 times that of the m-PVDF/CNTs coating and was attributed to the connectivity of HTO. The anticorrosion of HTO/m-PVDF/CNTs was increased by 3 orders of magnitude than that of m-PVDF/CNTs owing to the synergistic effect between the HTO and CNTs in blocking the invasion of corrosive species. This research provides a unique way to design and fabricate high-thermal-conductivity composite coatings with high anticorrosion by the synergism between carbon nanofiller and HTO.

Upcycling the electroplating sludge (EPS) and PET waste into metal–organic-frameworks (MOFs) is beneficial for both pollution mitigation and sustainable economy. Herein, we report a green synthesis of Ni-MOF nanocrystals by simultaneously using EPS and PET waste as precursors without any precedent. In particular, when EPS was fully utilized, with numerous Fe3+/Cu2+ ions coexisting with Ni2+ ions, the desired Ni-MOFs could still be successfully fabricated. The Ni-MOF nanocatalysts exhibited an excellent activity towards the photoreduction of CO2, giving 9.68 × 103 μmol h−1 g−1 of CO with 96.7% selectivity over H2 evolution. Additionally, the apparent quantum yield at 420 nm is 1.36%, which is superior to that of most catalysts in similar systems. This study clearly suggests that the MOF nanocrystals with excellent photocatalytic performances could be successfully fabricated from solid wastes.

The photoreduction of diluted CO2 into value-added solar fuel is a discipline at the forefront of energy and environmental research. However, this exploration largely suffers from unsatisfactory activity and selectivity. Herein, lattice-strained nickel hydroxide nanosheets (NSs) were successfully constructed via a vanadium-doped strategy toward the photoreduction of diluted CO2. X-ray absorption fine structure spectroscopy and Williamson–Hall analysis based on X-ray diffraction revealed the formation of lattice strain on the surface of the Ni(OH)2 NSs. Consequently, the lattice-strained sample exhibited the highest CO production yield of 20.7 μmol with a CO selectivity of 97% after 3 h in pure CO2, which were almost 4 and 1.3 times those of its parent Ni(OH)2 NS. Even in diluted CO2 (0.1 atm), it exhibited a CO production rate of 5.8 μmol h−1 with a CO selectivity of 91.3%, surpassing most previous works in pure CO2. Further characterizations revealed that the lattice strain could greatly improve the CO2 adsorption and activation, and the separation efficiency of the photogenerated carriers, thus leading to an enhancement in the carbon dioxide reduction activity. This work discloses a clear atomic-level correlation between lattice strain and diluted CO2 photoreduction, which lays a foundation for reinventing their applications in photocatalysis, among other applications.

Single-element phosphorus has received extensive attention in recent years because of its remarkable photocatalytic properties. In the present experiment, amorphous red phosphorus was controllably transformed into [P12(4)]P2[and Hittorf's phosphorus structures by performing bismuth catalysis. The temperature-controllable chemical vapor transport reaction realized the conversion of more than 90% of amorphous red phosphorus to single-phase crystalline red phosphorus. Under very mild ultrasonic treatment, the high-quality [P12(4)]P2[microbelts and Hittorf's phosphorus microrods were stripped into a few layers of nanobelts and sheet-like structures, respectively. As non-metallic catalysts, their rapid photocatalytic degradations of pollutants (methyl orange) and high hydrogen evolution rates revealed the rapid charge transfer and application potential of the crystalline red phosphorus catalyst. The results of this work could provide new ideas for the development of phosphorus-based crystalline photocatalytic systems.

WC–Al2O3 composites possess higher corrosion resistance compared with WC–Co cemented carbide. The main corrosion mechanism for WC–Al2O3 composites is the oxidation of the WC phase.

As an advanced two-dimensional (2D) material with unique properties, black phosphorus (BP) has attracted great attention in a variety of fields. One of the main obstacles for the practical application of BP is the poor ambient stability of few-layer BP, especially under light irradiation. In this study, a light-absorbing conjugated polymer is functionalized on the surface of BP during the exfoliation process, yielding BP nanosheets with light-resistance. The obtained BP/polymer nanosheets demonstrate enhanced stability compared to pure BP under sunlight. Systematic characterization reveals that the crystal structure and electronic characteristics of BP are well retained after 30 days of sun exposure. This convenient and efficient conjugated polymer passivation provides a novel light-prohibited method to improve the stability of BP for future applications.

Host–guest molecular crystals are classical types of molecular materials widely applied for fluorescent sensors, absorption, separation, etc. Their significance lies in deciphering the intermolecular interactions in crystal engineering and expanding the scope of pharmaceuticals and chemical-responsive smart materials. Here, we report three flexible host–guest molecular solvate crystals, 1·CH2Cl2, 1·dioxane, and 1·DMF, that crystallize with a much lower boiling point guest dichloromethane (DCM, 313 K), and high boiling points guest dioxane (374 K) and dimethylformamide (DMF, 426 K). Surprisingly, thermogravimetric and crystallographic characterizations show that 1·CH2Cl2 has a relatively high desolvation onset temperature of 390 K, which is much higher than that of 1·dioxane (305 K) and 1·DMF (307 K). Crystal structure analysis shows that this high stability originates from the confinement and steric effects of the trapped guest solvent molecules in the crystal cavities. Powder X-ray diffraction shows that the three compounds' desolvated powder can self-trap the CH2Cl2 (DCM) molecules, returning to the 1·CH2Cl2 state. Moreover, spectroscopic characterization presents an emission redshift of about 30 nm for 1·dioxane and 1·DMF compared to that of the former. These results are attributed to the flexible host plate's dihedral angle that undergoes a drastic change of about 50° which leads to the greatly enhanced conjugation degree of the host plate.

Functional dynamic molecular crystals have drawn increasing interest in exploring next-generation flexible and smart materials. Molecular rotors, as a typical type of dynamic material, are good candidates that can exhibit bulk properties and functionalities. Herein, we report a molecular rotor crystal as a model system to show a unique structural phase transition-related ferroelasticity. The molecular rotor is dumbbell shaped containing a freely rotating axial rotator and multiple peripheral tert-butyl groups on the two plates with restricted motions. The crystal undergoes a ferroelastic structural phase transition at 263 K with unconventional inverse temperature symmetry breaking (ITSB), i.e., a higher-symmetric low-temperature paraelectric phase (point group mmm) vs. a lower-symmetric high-temperature ferroelastic phase (point group 2/m). Combined crystallographic and NMR spectroscopy studies reveal that unequal motions of the peripheral tert-butyl rotators and anisotropic steric repulsion among the molecules are the key cooperative intermolecular interactions to drive a concerted molecular movement to result in the unique ferroelastic phase transition with ITSB. Our study may open avenues for designing and exploring new types of dynamic functional materials.

Photocatalytic reduction of CO2 holds tremendous promise for alleviating the energy crisis. Despite the progress that has been made, there are still some challenges to overcome, such as the realization under real sunlight rather than the simulation condition. In this work, ultrathin Ni2(OH)(PO4) nanotubes (NTs) prepared through hydrothermal route are applied as a novel catalyst for photocatalytic reduction of CO2 under real sunlight. The prepared Ni2(OH)(PO4) NTs exhibit a 11.3 µmol·h−1 CO production rate with 96.1% CO selectivity. Interestingly, Ni2(OH)(PO4) NTs have a positive impact on the facilitation of photoreduction in diluted CO2. Notably, when the system is performed under real sunlight, Ni2(OH)(PO4) NTs afford an accumulated CO of ca. 26.8 µmol with 96.9% CO selectivity, exceeding most previous inorganic catalysts under simulated irradiation in the laboratory. Our experimental results demonstrate that the multisynergetic effects induced by surface-OH and the lattice strain serve as highly active sites for CO2 molecular adsorption and activation as well as electron transfer, hence enhancing photoreduction activity. Therefore, this work provides experimental basis that CO2 photocatalysis can be put into practical use.

In this study, the WC reinforced Fe-based composite coatings with various CeO2 contents were fabricated on the H13 hot-working die steel by laser cladding. The high-temperature wear resistance of c...

In this study, WC-Al2O3 composite was fabricated by vacuum hot-pressing sintering. The corrosion behavior of WC-Al2O3 composite in NaOH and H2SO4 solutions was investigated by electrochemical measurements. The corrosion mechanisms were analyzed and revealed in light of corrosion morphology observation and composition characterization. The results confirmed that WC-Al2O3 composite possessed higher corrosion resistance than WC-Co hard metal in H2SO4 solution. Conversely, WC-Al2O3 composite behaved similar corrosion resistance compared with WC-Co hard metal in NaOH solution. The key reason for higher corrosion resistance in H2SO4 solution is the stable WO3 passive film. The oxidation of WC phase leads to neck cracks along with grain boundaries, which is attributed to the preferential corrosion of grain boundary and the stress derived from the volume expansion during polarization and drying processes. In NaOH solution, the corrosion mechanism of WC-Al2O3 composite mainly attributed to the dissolution of WC phase, but Al2O3 phase is relatively stable.

Fully dense WC-Al2O3 platelet composites with VC additive were fabricated by hot-press sintering. Their mechanical properties and microstructure were examined. The contents of Al2O3 platelet (Al2O3...

In view of the urgent need for the safety performance of the braided wire ropes in power grid construction, this study analyzes the mechanical responds of a braided wire rope under the tension and torsional loads. The mechanical responds of the strands under tension, torsional, and tension–torsion loads are studied, and the mechanical response equations of the strands under the above loads are obtained. Furthermore, a mechanical respond model of the rope under the tension and torsional loads is established using the method of rope strand unfolding. The strain of the strands in the axial direction of the rope is used to determine the strain of the braided wire rope. The stress and strain expressions of the whole rope under the tensile–torsional load are obtained. The whole rope test under the tension–torsion load is carried out, and the axial displacement curve under the same load is obtained. The reliability of the mechanical model is verified by comparing the experimental value with the theoretical value.

In order to solve the problem of forming parts with complex shape and small local feature size, solid granules medium forming (SGMF) was adopted. A part of magnesium alloy AZ31B with double-cone shape was taken as an example to analyze the forming process. The parameters of Gurson–Tvergaard–Needleman (GTN) were identified by an inverse method, comparing the experimental results with the numerical results. Based on the GTN model, the coupled finite element and discrete element (FE-DE) method was applied to simulate the forming process of the double-cone part with SGMF technology, and the relevant forming experiments were carried out. The results show that the quality of the workpiece can be improved with different friction coefficient of different area of the part. The fracture behavior and final wall thickness distribution obtained by experiment consist with those by simulation. So, it demonstrates the applicability of the FE-DE method with GTN damage model in analyzing formability of magnesium alloy, and the FE-DE method could embody the medium discrete characteristics fully during SGMF technology.

Ceramic materials have been extensively used as armour materials for nearly 50 years and continue to attract great interest in the field of defense technology. As confinement is crucial for ceramic...

Three different alumina/aluminum bi-layer armors having different striking faces, i.e., monolithic alumina, mosaic alumina, and mosaic alumina enhanced by aluminum honeycomb, were fabricated and tested under the impact of the flat projectile. The ballistic performance of each armor type was also investigated using three-dimensional (3D) finite element (FE) simulations. Upon validating the FE simulation results with experimental measurements, the ballistic limit velocity and failure mechanisms for each type of armor, as well as the influence of ceramic tile size, impact position, border effect, and inter tile gap width were quantified. For the enhanced mosaic armor, the metallic honeycomb lattice performed as a cellular skeleton to confine the ceramic tiles and fragments, leading to enhanced ballistic resistance. Besides, the honeycomb enhanced mosaic armor was also found to have much improved multi-hit ballistic resistance in comparison with monolithic and mosaic alumina. The honeycomb preserved the structural integrity of the mosaic armor so that a high level of residual ballistic resistance remained even after impact. With the extended reliability calculation method, single shot ballistic data were used to estimate the performance of the honeycomb enhanced mosaic armor under multiple projectile impacts.

Converting carbon dioxide (CO2) to diverse value-added products through photocatalysis can validly alleviate the critical issues of greenhouse effect and energy shortages simultaneously. In particular, based on practical considerations, exploring novel catalysts to achieve efficient photoreduction of diluted CO2 is necessary and urgent. However, this process is extremely challenging owing to the disturbance of competitive adsorption at low CO2 concentration. Herein, we delicately synthesize oxygen vacancy-laden NiO nanoplatelets (r-NiO) via calcination under Ar protection to reduce diluted CO2 through visible light irradiation (> 400 nm) assisted by a Ru-based photosensitizer. Benefitting from the strongly CO2 adsorption energy of oxygen vacancies, which was confirmed by density functional calculations, the r-NiO catalysts exhibit higher activity and selectivity (6.28 × 103 µmol·h−1·g−1; 82.11%) for diluted CO2-to-CO conversion than that of the normal NiO (3.94 × 103 µmol·h−1·g−1; 65.26%). Besides, the presence of oxygen vacancies can also promote the separation of electron-hole pairs. Our research demonstrates that oxygen vacancies could act as promising candidates for photocatalytic CO2 reduction, offering fundamental guidance for the actual photoreduction of diluted CO2 in the future.

In spite of the great potential in leading next-generation energy storage technology, Li-S batteries suffer rapid capacity decay arising from the shuttling effect of lithium polysulfides (LiPSs), a major concern that must be addressed before commercialization can be realized. To tackle this challenge, we demonstrate a facile approach to fabricate a hierarchically structured composite of Fe2P@nitrogen, phosphorus codoped carbon (Fe2P@NPC) by direct biological recycling of iron metal from electroplating sludge using bacteria. This material, featuring uniform dispersion of Fe2P nanoparticles (NPs) in porous NPC matrix, effectively adapts volume variation of sulfur upon cycling and simultaneously provides multiple channels for efficient lithium ion transport. In addition, Fe2P NPs with strong adhesion properties of tightly anchored soluble LiPSs formed during discharge can significantly facilitate the decomposition of Li2S during the subsequent charging process. The Li-S cell built on this cathode architecture delivers high specific capacity (1555.7 mAh g-1 at 0.1 C), appreciable rate capability (679.7 mAh g-1 at 10 C), and greatly enhanced cycling performance (761.9 mAh g-1 at 1.0 C after 500 cycles).

The purpose of this paper is to examine the influence of cold spraying parameters on the performance of Fe-based amorphous alloy (FAA) coating. A FeCoCrMoBCY amorphous alloy coating was prepared on...

Isothermal and non-isothermal pearlite transformations under 840°C warm-rolled and 950°C hot-rolled were researched. It was found that the pearlite nuclei at grain boundary and defects were increas...

Laser cladding technology is widely used in the surface modification of parts due to its excellent properties such as high hardness, high wear resistance and corrosion resistance. Extends the life of these parts under normal use conditions, greatly reducing production costs. In this paper, the influence of different parameters such as laser cladding process parameters—laser power and scanning speed, and their interaction on the performance of mold cladding layer is discussed, and the future development direction of laser cladding technology in mold is prospected.

With the rapid development of modern industry, mold as a basic hardware facility has become one of the important factors affecting the development of modern industry. The surface quality and working reliability of the mold have a direct impact on the quality of the part. Faced with a large number of failed molds in industrial production, fast and reliable mold repair technology can realize mold reuse under the premise of ensuring mold performance. It effectively shortens the construction period, saves costs and reduces mold waste. The article outlines the characteristics of wire and arc additive manufacturing technology, selective electron beam melting technology and laser cladding technology in additive manufacturing technology. The application characteristics of three additive manufacturing technologies in mold repair are analyzed. The application prospect of laser cladding technology in mold repair is pointed out. In view of the improved work reliability, the direction of laser cladding technology in the field of mold repair can be prospected.

We developed a novel high-performance L12-strengthened high-entropy alloy (HEA) in the multicomponent Ni-Co-Fe-Cr-Al-Nb system. The phase transformation, mechanical properties and associated deformation behaviors were systematically investigated through combinational analyses involving the three-dimensional atom probe tomography (3D-APT), transmission electron microscopy (TEM) and first-principles calculations. In contrast to conventional alloys that generally strengthened by Ni3(Al, Ti)-type precipitates, a high density of coherent L12 nanoprecipitates with a new chemical constitution of (Ni, Co, Fe, Cr)3(Al, Nb) can be controllably introduced via elaboratively tuning the content of Al and Nb, resulting in a large lattice misfit of ~0.78% that rarely achieved in previous HEAs. The newly developed (Ni2Co2FeCr)92Al4Nb4 HEA enables excellent tensile properties at a large temperature window from room temperature to 870 °C. More remarkably, an anomalous growth in yield strength can be observed at the temperatures above 600 °C, showing a peak yield stress over 720 MPa when deformed at 760 °C, which surpasses most of the previous L12-strengthened HEAs, as well as the commercial superalloys. Detailed TEM analyses revealed that the multicomponent L12 precipitates are mainly sheared by the super-partial dislocations, forming superlattice intrinsic stacking fault (SISF) loops coupled with antiphase boundaries (APBs). Such an interesting deformation substructure enables sustained work hardening and produces high tensile strengths at the high temperatures. The underlying mechanisms of those SISF loops were carefully discussed, which could be possibly ascribed to the local elemental segregation on the planner faults.

All-metallic truncated conical sandwich shells with corrugated cores (TCSS) were investigated for crashworthiness under quasi-static oblique compression using a combined experimental and numerical ...

All-metallic sandwich-walled cylindrical and conical structures for aerospace applications often require simultaneous excellent vibration and load-carrying capacities. In the present study, the free vibration and axial compression behaviors of cylindrical and truncated conical sandwich shells with corrugated cores are investigated using a combined experimental and numerical approach. Excellent agreement between experimental measurements and finite element simulations for representative vibration and axial compression characteristics is achieved. Parametric studies based on the response surface model are subsequently performed to quantify the influence of key geometrical parameters on vibration and axial compression performance. A multi-functional collaborative design to meet the requirement of high load-bearing capacity subjected to the constraint of low natural frequency is also carried out, which demonstrates the unique advantages of the novel sandwich-walled shells for aeronautical and astronautical applications.

A strong sunlight-absorptive ability and high dispersity are considered as two key requirements of supported metal catalysts for efficient photothermal CO2 conversions. The former can be improved b...

The microstructures and tribological properties of CoCrFeMoNi high entropy alloy (HEA) before and after sulfurization were compared and discussed in the present study. The results showed that the CoCrFeMoNi HEA was mainly composed of FCC solid solution. After being sulfurized at 260℃ for 2 h, the FeS/MoS2 multisulfides solid lubricant films with a thickness of approximately 5.0 μm were successfully fabricated and well combined with the HEA. The stable friction coefficients and weight losses of the sulfurized HEA (0.15 and 4.25 mg) were decreased obviously than the original HEA (0.47 and 15.1 mg). At the beginning of the friction, the friction coefficient of the sulfurized HEA was easier to reach into stable stage. Because of the synergistic work of FeS and MoS2 lubricant phases, the sulfides boundary lubricant films were formed in the later stage of friction under the wearing condition, which could help the friction system work for longer time under lower friction coefficient. Keywords: Laser cladding, Ion sulfurization, High entropy alloy, Multisulfides film, Tribological property

The butt welding of bimetal composite pipes generally adopts single-side welding, which easily gives rise to the problems such as high cost or crack initiation. In this paper, the butt welding of L415/316L bimetal mechanical lined pipes was conducted using post-internal-welding process, which is double-side welding process, proposed by the authors. Firstly, the effect of groove shape on the weld process was discussed. Then, microstructures and mechanical and corrosion-resistance properties of welded joints welded using two different welding materials, 309MoL and 309L, were investigated. The results show that the most suitable groove is that L415 is V shape with angle of 60° and blunt edge of 1 mm and 316L is stripped 6–8 mm. The weld of both 309MoL and 309L is composed of austenite and a small amount of ferrite, but the presence of Mo can refine the grains and increase the content of ferrite phase. The width of transition layer is about 0.6–0.8 mm located at the weld junction of stainless steel weld and carbon steel weld, and the transition layer mainly contains martensite. The tensile and bending performances of the welded joints using both 309MoL and 309L do meet the standard requirements. The welding wire 309MoL can improve the corrosion resistance to Cl− compared to 309L. It is advisable to use the post-internal-welding process and 309MoL for the welding of bimetal composite pipes under environments containing Cl−.