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The current study suggested that nano-scale twins in magnesium alloys can significantly affect the elastic limit, ultimate strength and corrosion performance. However, the complicated process of nano-scale twins preparation limits its industrial application. In this paper, the microstructure with submicron twins and precipitates of ZK60 magnesium alloy was designed by room temperature multi-directional forging (MDF) process, aiming to improve the enhancement effect of submicron twins by compensating the denseness of coherent interfaces with diffusely distributed precipitates. The results show that the MDFed ZK60 alloy can obtain high strength (yield stress (YS): 248.5 MPa, ultimate tensile strengths (UTS): 371.4 MPa). Good comprehensive mechanical properties can be finally achieved after heat treatment at 150 °C (YS: 226.5 MPa, UTS: 352.6 MPa, elongation: 17.1%). Submicron lamellar {10–12} twins were formed within the alloy due to the small strains in multi-passes of forging. During heat treatment at 150 °C, a large amount of β1' phase was diffusely precipitated within the matrix and twins. The presence of precipitates effectively increases the denseness of dislocation motion barriers in submicron twins, which enables twin-boundary enhancement of ZK60 magnesium alloy. This work provides a new idea for the design of low-cost magnesium alloy forgings in industry. [ABSTRACT FROM AUTHOR]

Understanding the mechanisms behind sintering Cu-Ag core–shell nanoparticles can help us optimize the sintering process parameters and design the core–shell structure to achieve the desired sintering structure. In this paper, we employed molecular dynamics simulations to investigate the sintering behaviors and mechanisms of CS NPs, taking into account the effects of shell thickness, particle size, and temperature. Our results revealed that dislocation loops in Cu-Ag CS NPs played a crucial role in sintering by emitting dislocations that facilitated crystal evolution, thereby reducing the number of amorphous structures. The state of dislocation loops could be controlled by shell thickness and NP size. As the shell thickness decreased to 0.5 nm, the structure of the dislocation loops could not be generated due to the extremely chaotic and thin Ag atoms. Furthermore, for NPs of the same size, the CS NP with a 0.5-nm shell thickness was the most active. Despite the neck not consisting of a Cu core, the Cu core, particularly its interface, could still participate in the sintering process. At 900 K, limited interface diffusion could be activated. [ABSTRACT FROM AUTHOR]

In this paper, performance of ZrO2 and CeO2 supported Ni catalysts on CO2 hydrogenation reaction was investigated in continuous flow reactor. The results revealed that Ni/ZrO2 catalyst exhibited superior performance compared to Ni/CeO2, with a CO2 conversion rate of 71.84%, a CH4 formation rate of 21.03 mmol g−1 h−1, and excellent reaction stability at 400 °C. And the activation energy of Ni/ZrO2 was lower than that of Ni/CeO2. N2 adsorption–desorption, SEM, XRD, XPS, CO2-TPD and O2-TPO analysis results suggest that Ni/ZrO2 is a multi-stage pore material, which has slit holes formed by the accumulation of sheet-like particles, as well as a superior dispersion of Ni on ZrO2. Moreover, Ni/ZrO2 shows higher alkalinity and remarkable resistance to carbon accumulation. DFT calculations demonstrated that CO2 can be more easily adsorbed on ZrO2 surface, and one O-terminus of CO2 is closer to top sites of ZrO2, which is favorable for electron transfer and promotes the activation of CO2. [ABSTRACT FROM AUTHOR]

As a typical mimic of natural enzymes, carbon-based peroxidase-like nanozymes have developed vigorously recent years, which are widely used in biomedical research. In this paper, borocarbonitride nanotubes (BCNNTs) were synthesized via assembly and pyrolysis of small organic molecules achieving boron (B) and nitrogen (N) co-doping in carbon nanotubes. As non-metallic nanozymes, BCNNTs exhibited high peroxidase-like activity and photothermal conversion capability, which were applied to bacterial colorimetric point-of-care testing (POCT) and in situ synergistic inactivation. By BCNNTs functionalized with specific antibody of Staphylococcus aureus, sensitive visible and rapid POCT of Staphylococcus aureus was accomplished. Right after the bacterial assay, the bacterial inactivation proceeded efficiently owing to both the catalytic decomposition of H2O2 and photothermal disinfection induced by BCNNT nanozymes, that eliminated bacterial contamination and further transmission without delay. The multifunctional BCNNT nanozymes possessed high peroxidase-like activity, photothermal property, good biocompatibility and stability, which had great potentials in food safety testing, environmental monitoring, and microbial control and therapy. [ABSTRACT FROM AUTHOR]

The impact of solute Al on the penetration of Cu atoms into the Fe grain boundary (GB) in the Fe–Cu embrittlement system was investigated by performing molecular dynamics simulations. Furthermore, the first principle density functional theory calculation was also employed to determine the binding properties and the electronic structure of GBs doped with solute atoms. The inhibition mechanism of liquid metal embrittlement (LME) cracks in the Fe–Cu system by Al was analyzed at the atomic scale by conducting simulations and calculations. The results show that the diffusion rate of Al along with the GB direction was much higher than that of Cu, and the preferential penetration and segregation of Al atoms acted as a barrier layer. Moreover, the addition of Al reduced the potential energy of Cu atoms, thus stabilizing their motion. These factors significantly inhibited the diffusion of Cu atoms along with the GB direction. The binding property of Fe GB doped with a high concentration of Cu was severely deteriorated, while the Al doping improved the atomic bonding. GBs with higher binding properties are less susceptible to fracture and groove under the application of tensile stress. This paper presents a novel perspective on the inhibition mechanism of LME cracks by doping a third component to inhibit the penetration of embrittlement atoms. [ABSTRACT FROM AUTHOR]

In this study, we utilized experiments and the Visco-plastic Self Consistent (VPSC) model to investigate the tensile mechanical behavior and texture evolution of the new weak texture Mg–1Al–0.5Mn–0.3Gd magnesium alloy, unlike the traditional strong basal texture. The result showed that the weak texture magnesium alloy exhibited good isotropic behavior during the tensile in various directions. In addition, we observed that it displayed similar macroscopic mechanical behavior and microscopic texture evolution rules. In particular, the increase in the prismatic < a > slip was significant in the early stages of plastic deformation, leading to a slightly higher flow stress along the rolling direction (RD) compared to the transverse direction (TD). In order to study the effect of {10–12} twinning on mechanical behavior and texture evolution, some scholars adopted inhibition of their activation for verification. However, in this paper, the effects of {10–12} twinning on mechanical behavior and texture evolution of magnesium alloys were verified by comparing only activating and only inhibiting {10–12} twinning, it was found that the activity of {10–12} twinning can significantly reduce the yield strength and strain hardening rate of the weak texture magnesium alloy during the tensile along TD. [ABSTRACT FROM AUTHOR]

NiTi alloy has excellent corrosion resistance and wear resistance, and is an important protective coating being developed for marine equipment. In this paper, the crack and pore-free high-quality NiTi coatings were firstly synthesized in situ by extreme high-speed laser cladding (EHLA) technology under high temperature oxidation environment. The effects of laser power of EHLA on the temperature field, stress field and coating properties of NiTi coatings were studied by combining finite element calculation and experiments. The results show that a corrosion-resistant and wear-resistant TiO2 oxide film was generated in situ on the coating surface during EHLA process. Furthermore, the denser oxide film can be obtained by proper annealing treatment, and the wear resistance and corrosion resistance of the sample can be further improved. This provides a feasible fashion for EHLA to in situ synthesize wear-resistant and corrosion-resistant alloy coatings with low defects. [ABSTRACT FROM AUTHOR]

Copper/steel composite is a kind of composite with excellent performance and broad application prospects. In this paper, the micro-morphology and structure of the interface of copper/steel composite prepared by the hot-dip casting were observed by scanning electron microscope and transmission electron microscope, and the formation mechanism of the interface area was explored. The results show that the hot-dip casting temperature has a great influence on the micro-structure and morphology of the copper/steel interface area. When the hot-dip casting temperature is lower than 1125 °C, the copper/steel interface area is basically in a straight line. Even if the hot-dip casting time is extended, the interface characteristics change little. At 1100 °C, the copper-rich phase precipitated at the interface area is the coherent precipitates of Cu and BCC-Fe, with the crystal orientation <110> and the diameter about 10 nm ~ 30 nm. When the hot-dip casting temperature reaches 1150 °C, the copper/steel interface area begins to appear new micro-morphology, and the range of new micro-morphology becomes larger and larger with the increase in the hot-dip casting temperature and the extension of the hot-dip casting time. At 1200 °C, the copper-rich phase precipitated at the interface is the coherent precipitates of FCC-Cu and FCC-Fe, with the crystal orientation <100> and the size similar to that at 1100 °C. In the process of the hot-dip casting, the formation of the copper/steel interface area experienced three stages: the co-temperature of copper/steel and the wetting of copper liquid on solid steel, the formation and transformation of the solid–liquid mixed layer between steel and copper liquid and the evolution stage of the liquid–solid mixed layer during cooling and solidification. This kind of interface zone with gradual structure tightly connects the steel matrix and solidified copper together, to form a copper/steel composite with strong bonding. [ABSTRACT FROM AUTHOR]

Due to the machining-induced residual stress while processing, the machining distortion of thin-walled 7050 aluminum alloy parts occurs easily, which greatly affects the pass rate of the products. Herein, electromagnetic coupling treatment (EMCT) was proposed to relieve the residual stress of 7050 aluminum alloy. It was found that EMCT had a significant effect on residual stress relief (13.3–89.7%). The energy input by EMCT promoted the movement of dislocation, resulting in the uniform distribution of microplastic strain, the release of stored elastic strain energy, and the residual stress relief, ultimately. A numerical simulation method to visualize the evolution of the electromagnetic field, the stress, and the strain in the materials was proposed to explain the causes of microplastic strain. Specimen #5 with the optimal EMCT processing parameter (1.5 T, 1.5 V) was considered to be the most effective for both residual stress relief and mechanical property enhancement, in which the residual stress decreased by 85.1% and the tensile strength increased by 8.3%. In this paper, it is proposed that EMCT can be used as an effective method to reduce the residual stress of 7050 aluminum alloy. Moreover, it has certain technical reference value for the study of residual stress relief of other thin-walled part materials. [ABSTRACT FROM AUTHOR]

In the last 12 years, conventional solar cells, especially silicon-based, have increased their efficiency by 1.1%; however, the energy transformation efficiency of perovskite-based photovoltaics has reached from 3.8% to 25.7% within the same time frame. Perovskite solar cells have been evolved as captivating domain of research in recent years by virtue of phenomenal intrinsic properties exhibited by perovskite materials and gradual optimization of hole transport layer along with perovskite film. This review paper elaborates various materials utilized as hole transport layers in perovskite solar cells. Firstly, the origin of perovskite-based cells is described followed by their configuration/ structure. The paper then elaborates the function of hole transport layer in improving the performance of perovskite solar cells. Further, it throws light on categorization of hole transport materials in organic and inorganic group including their advantages and disadvantages. Particularly, the organic hole transport materials, viz. PTAA, PEDOT:PSS, P3HT, Spiro-OMeTAD, and inorganic hole transport materials, viz. CuOx, CuSCN, CuI, NiOx and transition metal dichalcogenides (TMDs) were briefly elaborated. Through this review paper, the design and applications of recently synthesized hole transport materials that promote the device performance of perovskite solar cells have been also discussed. [ABSTRACT FROM AUTHOR]

The Cu–Fe–P alloy is the mainstream material of IC lead frame at present, which plays a key role in electrical signal transmission and mechanical fixation between bearing chip and external circuit board. With the development of integrated circuits toward high integration and extreme miniaturization, copper alloy strips for lead frames are required to have excellent electrical and mechanical properties, as well as excellent softening resistance under short-term high temperature service conditions. In this paper, the effects of annealing temperature (300, 400, 500 °C) on texture orientation and strength, and precipitates characteristics (morphology, size, interfacial relationship, etc.) of as-cold rolled Cu–2.18Fe–0.03P alloy were studied by means of EBSD and TEM. It is found that annealing at low temperature does not change the texture type, but it affects the texture strength compared with the as-cold rolled alloy. Cubic texture {001} < 100 > and R-type texture {111} < 112 > appear in the annealed alloy. The texture strength increases with the increase in annealing temperature, and the preferred orientation is more obvious. In addition, we found that there are two kinds of precipitated phases in the copper matrix, namely spherical α-Fe phase and irregular Fe3P phase. We further find out the coexistence state of the two precipitates and their evolution with annealing temperature. With the increase in annealing temperature from 300 to 500 °C, the size of the main strengthening phase α-Fe increases and the orientation relationship between α-Fe phase and the matrix changes from coherent to semi-coherent. On this basis, we found that the decrease in texture strength, the change of coherence relationship of α-Fe phase, and the decrease in dislocation barrier are the main factors leading to the softening of Cu–2.18Fe–0.03P alloy at high temperature. The research results of this paper are meaningful in guiding the development of high-end copper alloy strip in the field of electronic information. [ABSTRACT FROM AUTHOR]

This study investigates potentiodynamic synthesis of polyaniline (PANI) using pencil graphite electrodes (PGEs), aiming to elucidate deposition mechanisms under simple experimental conditions. By exploring PANI electrosynthesis through electrochemical, spectroscopic, and computational approaches, valuable insights into the physicochemical aspects of aniline polymerization are gained. The proposed synthetic method was challenged for the development of a new molecularly imprinted polymer for chloramphenicol on the surface of PGEs to obtain an innovative impedimetric sensor. The sensing platform shows a linear response in the target concentration range between 0.1 and 17.5 nM, in aqueous solutions, with a limit of detection of 0.03 nM and a limit of quantification of 0.09 nM. The results obtained suggest that the synthesis method proposed provide a way to obtain stable and electroactive polyaniline film with huge potential application. [ABSTRACT FROM AUTHOR]

It is vital to reveal the effect of microstructure features on the corrosion behavior of pure aluminum anode in alkaline electrolyte for Al-air batteries. In this paper, we extensively studied the influence of mechanical deformation on the corrosion microstructure and then corrosion features of pure aluminum anode. The results demonstrate that the cold-rolling deformation could facilitate the grain size refinement of pure aluminum. Surprisingly, the aluminum anodes with smaller grain sizes and larger grain boundary areas could effectively improve the corrosion resistance. The further characterization of the microstructure indicates that the deformation is capable of causing the fracture of the cathodic secondary phase precipitate clusters thus weakening the galvanic corrosion effects. The results of this paper could gain insights into the design and processing of pure aluminum for Al-air battery. [ABSTRACT FROM AUTHOR]

Acylhydrazone bonds can participate in dynamic exchange reactions under acid-stimulated conditions, and disulfide bonds can participate in dynamic exchange reactions under thermally stimulated conditions. It is of great significance to prepare epoxy vitrimer that can rapidly self-repair under acid and thermal stimulation conditions. In this paper, vanillin was used as raw material, and monomer (VAN-AD) containing acylhydrazone bond was synthesized by reaction with adipic dihydrazide. Then, VAN-AD and 4-aminophenyl disulfide (SS) were cured together with glycerol triglycidyl ether to prepare an epoxy vitrimer with acylhydrazone and disulfide dual dynamic covalent bonds. Where VAN-AD provides some of the flexible chain segments and acylhydrazone bonds and SS provides the aromatic phenyl and disulfide bonds. The material was prepared in a simple process and under mild condition, and the properties of the material were optimized by changing the ratio of VAN-AD to SS. The Tg of the material was 50 °C when the ratio of SS was the highest, the thermal stability was enhanced with the increase of the ratio of SS, and the maximum tensile strength up to 50.9 MPa, and the material can be completely degraded by DMF with 5% HCl. It is worth noting that the material shows rapid self-healing properties under acid-heat conditions, self-healing rates up to 97.37%, and the tensile strength can reach 26 MPa after repair. The material can be successfully remodeled by hot pressing for 1 h at 140 °C and 10 MPa.Graphical abstract: Acylhydrazone bonds can participate in dynamic exchange reactions under acid-stimulated conditions, and disulfide bonds can participate in dynamic exchange reactions under thermally stimulated conditions. It is of great significance to prepare epoxy vitrimer that can rapidly self-repair under acid and thermal stimulation conditions. In this paper, vanillin was used as raw material, and monomer (VAN-AD) containing acylhydrazone bond was synthesized by reaction with adipic dihydrazide. Then, VAN-AD and 4-aminophenyl disulfide (SS) were cured together with glycerol triglycidyl ether to prepare an epoxy vitrimer with acylhydrazone and disulfide dual dynamic covalent bonds. Where VAN-AD provides some of the flexible chain segments and acylhydrazone bonds and SS provides the aromatic phenyl and disulfide bonds. The material was prepared in a simple process and under mild condition, and the properties of the material were optimized by changing the ratio of VAN-AD to SS. The Tg of the material was 50 °C when the ratio of SS was the highest, the thermal stability was enhanced with the increase of the ratio of SS, and the maximum tensile strength up to 50.9 MPa, and the material can be completely degraded by DMF with 5% HCl. It is worth noting that the material shows rapid self-healing properties under acid-heat conditions, self-healing rates up to 97.37%, and the tensile strength can reach 26 MPa after repair. The material can be successfully remodeled by hot pressing for 1 h at 140 °C and 10 MPa. [ABSTRACT FROM AUTHOR]

Modification of the surfaces of polymeric scaffolds is often required to make the material suitable for specific tissue engineering applications. Physico-chemical properties of scaffolds can be altered using various methods, such as plasma treatment, laser processing, chemical modifications, grafting with nanoparticles, or surface coating. In this paper physico-chemical modification of polycaprolactone (PCL) surface fibers was performed by exposing PCL samples to simultaneous soft X-ray/extreme ultraviolet (SXR/EUV) radiation and low-temperature, SXR/EUV-induced, nitrogen, and oxygen plasmas. The physical and chemical changes on modified PCL surfaces were examined using a scanning electron microscope and X-ray photoelectron spectroscopy, respectively. The effects of physico-chemical scaffold surface changes were verified with biological tests, i.e., MTT assay and immunofluorescence on murine osteoblast cell line (7F2). It was found that exposure of scaffolds to ionizing radiation and low-temperature plasmas induced strong chemical changes on their surface, i.e., appearance of various new chemical groups. Also, smoothing of the surface of PCL fibers, i.e., disappearance or significant reduction of the size of micropores on their fibers was also observed. Increased viability and adhesion of 7F2 osteoblasts on modified PCL samples after 24 h cell culture compared to non-treated PCL was also confirmed.Graphical abstract: Modification of the surfaces of polymeric scaffolds is often required to make the material suitable for specific tissue engineering applications. Physico-chemical properties of scaffolds can be altered using various methods, such as plasma treatment, laser processing, chemical modifications, grafting with nanoparticles, or surface coating. In this paper physico-chemical modification of polycaprolactone (PCL) surface fibers was performed by exposing PCL samples to simultaneous soft X-ray/extreme ultraviolet (SXR/EUV) radiation and low-temperature, SXR/EUV-induced, nitrogen, and oxygen plasmas. The physical and chemical changes on modified PCL surfaces were examined using a scanning electron microscope and X-ray photoelectron spectroscopy, respectively. The effects of physico-chemical scaffold surface changes were verified with biological tests, i.e., MTT assay and immunofluorescence on murine osteoblast cell line (7F2). It was found that exposure of scaffolds to ionizing radiation and low-temperature plasmas induced strong chemical changes on their surface, i.e., appearance of various new chemical groups. Also, smoothing of the surface of PCL fibers, i.e., disappearance or significant reduction of the size of micropores on their fibers was also observed. Increased viability and adhesion of 7F2 osteoblasts on modified PCL samples after 24 h cell culture compared to non-treated PCL was also confirmed. [ABSTRACT FROM AUTHOR]

Polymeric materials have gained immense significance in the field of biomedicine. Among these materials, poly(ε-caprolactone) (PCL) stands out as a prominent biocompatible and biodegradable polyester. This polymer has become extremely attractive in various fields due to its versatile properties and potential application in regenerative medicine, tissue engineering, and drug delivery. The unique combination of the desirable properties of PCL such as non-toxicity, low melting point and glass transition temperature, mechanical strength, compatibility with other polymers and therapeutic agents, and ease of processability makes this synthetic polymer an ideal material for a wide range of applications. Due to its ability to facilitate cell attachment and proliferation, mechanical compatibility with biological tissues, and controlled release of therapeutic agents, PCL is utilized for the fabrication of implants, scaffolds, and drug delivery systems. Herein, we aimed to provide the current state-of-the-art regarding PCL-based formulations including nanoparticles, microparticles, nanofibers, micelles, and films, and their diverse biomedical applications in tissue engineering, wound healing, drug delivery, and regenerative medicine. Furthermore, we discuss the active ingredients, composition, investigation status, and route of administration of these formulations. This paper also delves into various methods of preparing PCL-based formulations, including conventional techniques such as electrospinning and solvent casting as well as emerging methods, namely 3D printing, self-assembly, and microfluidics approaches, shedding light on their advantages and limitations. Commercial biomedical applications are another area that is addressed. Overall, this paper provides valuable insights into the advancements and potential of this biodegradable polymer in the biomedical field.Graphical abstract: Polymeric materials have gained immense significance in the field of biomedicine. Among these materials, poly(ε-caprolactone) (PCL) stands out as a prominent biocompatible and biodegradable polyester. This polymer has become extremely attractive in various fields due to its versatile properties and potential application in regenerative medicine, tissue engineering, and drug delivery. The unique combination of the desirable properties of PCL such as non-toxicity, low melting point and glass transition temperature, mechanical strength, compatibility with other polymers and therapeutic agents, and ease of processability makes this synthetic polymer an ideal material for a wide range of applications. Due to its ability to facilitate cell attachment and proliferation, mechanical compatibility with biological tissues, and controlled release of therapeutic agents, PCL is utilized for the fabrication of implants, scaffolds, and drug delivery systems. Herein, we aimed to provide the current state-of-the-art regarding PCL-based formulations including nanoparticles, microparticles, nanofibers, micelles, and films, and their diverse biomedical applications in tissue engineering, wound healing, drug delivery, and regenerative medicine. Furthermore, we discuss the active ingredients, composition, investigation status, and route of administration of these formulations. This paper also delves into various methods of preparing PCL-based formulations, including conventional techniques such as electrospinning and solvent casting as well as emerging methods, namely 3D printing, self-assembly, and microfluidics approaches, shedding light on their advantages and limitations. Commercial biomedical applications are another area that is addressed. Overall, this paper provides valuable insights into the advancements and potential of this biodegradable polymer in the biomedical field. [ABSTRACT FROM AUTHOR]

The deposition of a plasmonic metal layer on a nanostructured oxide surface is one of the important methods of preparing a platform for surface-enhanced Raman scattering (SERS) measurements. In this contribution, we describe the formation of SERS substrates by the deposition of a silver layer on ordered a Ta2O5 nanopore array. The influence of various experimental anodization process parameters on the morphology of a Ta2O5 nanopore array was carefully studied. It was found that the formation of a Ta2O5 nanopore array is possible under a broad potential range (15–50 V) in a highly acidic solution containing F− ions. In some cases, the nanopore array structures were covered by an outer layer rich in F− and SO42− ions, which could easily be removed using adhesive tape or by sonication. The deposition of an Ag layer led to SERS activity. The optimal Ag layer thickness was specified based on SEM and DRS measurements. The SERS substrates formed exhibited high point-to-point, sample-to-sample and time durability. [ABSTRACT FROM AUTHOR]

Low-density aerogels have shown great potential as excellent oil–water separation materials in dealing with the growing problem of marine pollution, but they typically suffer from low oil adsorption capacity, complex process flow, expensive raw materials, and poor recyclability. In this paper, inexpensive industrial raw material melamine was introduced into the framework of graphene aerogels, which can be formed into gels (NGAs) in just one step. High-temperature carbonized nitrogen-doped graphene aerogels (N0.5CGAs-2) have the advantages of ultralow density, high porosity, repeatable compressibility, hydrophobicity, and excellent adsorption capacity. In addition, depending on the characteristics of the contaminants, N0.5CGAs-2 can be selected for different recycling methods and exhibits excellent reusability in cycling. It has a high application value for solving water pollution problems caused by oil spill accidents and chemical spills. [ABSTRACT FROM AUTHOR]

Germanium selenide (GeSe), a mono-sulfide compound of group VI elements, has a crystal and semiconductor structure similar to black phosphorus, which means that it is very promising for applications in nanophotonic devices. In this paper, we prepared 5 mg ml−1 GeSe nanosheet suspensions by liquid-phase exfoliation technique and centrifuged the suspensions at different speeds to obtain GeSe nanosheets with different layer numbers to investigate the effect of nanosheet layer numbers on the third-order nonlinear optical properties of GeSe nanosheets. AFM microscopy is used to show that the number of layers in a nanosheet can be controlled using differential centrifugation techniques. The structure and defects of the exfoliated nanosheets were analyzed based on the results of Raman spectroscopy and X-ray energy spectrometry. The open-aperture Z-scan technique revealed that the nonlinear absorption effect of the nanosheet changed from saturation absorption to reverse saturation absorption when the number of nanosheet layers was gradually reduced. The closed-aperture Z-scan technique reveals that the nonlinear refraction effect enhanced when the number of nanosheet layers is gradually reduced. [ABSTRACT FROM AUTHOR]

Spherulite is the main microstructure feature of semicrystalline polymers, exhibiting a non-axisymmetric geometry with a sheaf structure in the center. In the initial stage of growth, spherulite is manifested initiation from the sheaf structure with a certain orientation. The size and orientation of sheaf structure are affected by various processing parameters. Previous research considered spherulite as completely radially symmetric structures, ignoring the effects of anisotropic sheaf on mechanical properties. In this paper, an anisotropic micromechanical model for evaluating the mechanical properties of semicrystalline polymers was proposed. The microstructure of single spherulite was modeled with different sheaf sizes, orientations, and crystallinities. The viscoplastic constitutive model together with the Arruda–Boyce model was used to describe the micromechanical behaviors of the crystalline lamellae and amorphous lamellae, respectively. The evolution of inhomogeneous plastic deformation, interlayer deformation and slip activities in spherulite was observed under tension. The results shown in this work enhance the understanding of the microstructure–property relationship of semicrystalline polymers, which, in turn, guides the development of advanced manufacturing techniques for tailoring mechanical properties. [ABSTRACT FROM AUTHOR]

In this paper, the deformation mechanisms of a Fe–2.25%Cr–1%Mo (P22) steel are studied after tensile tests at room temperature (RT) and 550 °C (HT), creep-fatigue tests at 550 °C and stress relaxation test at 550 °C (HTSR). The RT, HT and HTSR tests produced permanent strain of about 2.5% by different processes. Deformation features such as the orientation of the grains, local misorientation, grain boundary type and distribution, etc., were characterized using electron backscatter diffraction. Transmission electron microscopy was done subsequently to obtain greater insight into the dislocation substructures. The as-received sample had a ferritic–bainitic microstructure, and a large amount of local misorientation was found in the bainite, indicating plastic strain due to phase transformation. After tensile strain to 2.5% at room temperature, the dislocations formed very small substructures (~100–200 nm) in the ferrite grains, and most of the retained plastic strain seemed to be concentrated in the bainite after deformation. Both the ferrite and bainite showed much lower local misorientation and dislocation wall content after a tensile test to 2.5% strain at 550 °C. Compared to the RT tensile sample, after creep-fatigue at 550 °C, the substructures in ferrite opened up considerably and formed small-angle grain boundaries, with clean areas as large as 20–25 μm. After stress relaxation at 550 °C, the ferrite displayed even less substructure, while the bainite seemed to have greater amounts of local misorientation than in the creep-fatigue case. However, the degree of misorientation was less pronounced than in the room temperature tensile case. These results have been discussed with respect to the causes behind the phenomena observed herein and their possible effects on mechanical behaviour. [ABSTRACT FROM AUTHOR]

Endowing asphalt concrete with stable conductive properties is beneficial to develop smart pavement such as self-sensing, self-healing, self-deicing and snow-melting pavement, thus improving the service life and realizing the sustainable development of pavement. In this paper, the conductive properties and mechanisms of high anti-corrosion stainless steel wires (SSWs, with a diameter of 20 μm) and stainless steel fibers (SSFs, with a diameter of 0.2 mm) modified asphalt concrete fabricated by different mixing methods were investigated. Experimental results show that incorporating 1 vol% SSWs firstly with asphalt and mineral powder can reduce the direct current (DC) resistivity of asphalt concrete to 18.54 Ω·m and make alternate current resistivity independent of voltage frequency, while the DC resistivity of asphalt concrete with 24 vol% SSFs (firstly mixing SSFs with aggregates) is still as high as 104–106 Ω·m. The equivalent circuit obtained by electrochemical impedance spectroscopy and the conductivity calculated by general effective media equation illustrates that the conductive elements in SSFs modified asphalt concrete are mostly interface capacitors between SSFs, while low content of SSWs have overlapped to form the stable conductive path in asphalt concrete, resulting from the micro diameter, high aspect ratio, and high flexibility of SSWs. [ABSTRACT FROM AUTHOR]

Due to the excellent thermoelectric properties and low sintering temperature, nano-Ag paste is a promising die-attach material for high power electronic device. Unfortunately, it is difficult to resolve the critical issues including poor interfacial wettability, high porosity and poor high-temperature reliability of sintered nano-Ag joint. In this study, a novel bonding method was proposed to solve these problems by introducing Sn into the nano-Ag joint through the transient-liquid-phase (TLP) bonding technology. The Ag-Sn joint reported in this paper maintained excellent mechanical properties after high temperature aging and thermal shock test. The addition of Sn reduced the porosity of nano-Ag joint and improved the wettability of bonded interface. After aging at 200 °C for 2000 h, the shear strength still remains higher than 50 MPa. Besides, this bonding approach resolves the oxidization problem of Cu substrate at high temperature. The molecular dynamics (MD) simulation results indicate the addition of Sn could effectively inhibit the permeation of oxygen into the interface. [ABSTRACT FROM AUTHOR]

In this paper, the deformation behavior of a nickel-based single-crystal superalloy with [ 1 ¯ 40] and [ 3 ¯ 40] orientations was studied at room temperature by in situ electron backscattered diffraction (EBSD) tensile equipment. The mechanical properties, slip behavior and the corresponding Schmidt factor were analyzed. The deformation bands generated during the plastic deformation stage were found and characterized by using the electron backscattered diffraction (EBSD) technique. Furthermore, the formation and propagation of deformation bands played a softening effect on stress–strain curves; however, the secondary slip bands occurring after the propagation of deformation bands played a hardening effect. Finally, the formation of deformation band and its propagation on the mechanical properties are discussed. [ABSTRACT FROM AUTHOR]

This work mainly focuses on the generation of white light from sodium antimony zinc borate (BNZS) glasses as well as by introducing silver ions into the glass matrix through the Na+–Ag+ ion-exchange method. The glasses of 40B2O3–10Na2O–(50−x) ZnO–xSb2O3 (in mol%) where x = 0, 10, 20, 30, and 40 were prepared through melt quenching technique and are characterised by XRD, UV–VIS–NIR absorption spectra, photoluminescence, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) techniques. CIE 1931 chromaticity colour coordinates for all base glasses without silver fall within the blue region. Based on the ion-exchange duration, the colour coordinates shifted from blue to white light with the introduction of silver ions into the glass. This is due to the formation of silver nanoclusters of various dimensions and concentrations by different reduction and aggregation mechanisms in the glass matrix. The mechanism behind the evolution of white light generation has been analysed using the Raman and XPS spectral analysis. Traditional phosphors containing rare earth ions are widely used in displays, lasers, optical amplifiers, and white light-emitting diodes, having limitations such as narrow emission bands, low thermal stability, and their scarcity as well as high cost. Hence, this paper explores the generation of white light from rare earth-free glasses by embedding optically active nanoparticles into it and postmodifying its properties. [ABSTRACT FROM AUTHOR]

In order to improve the environmental problems caused by the extensive use of plastics, this paper introduced a new strategy to add and modify the physical structure, which could not only reduce the use of plastics, but also improve the mechanical properties of bamboo plastic composites. In this work, the bamboo-woven structure was introduced into the bamboo fiber/low density polyethylene (LDPE) composites to enhance the mechanical properties. Besides, to enhance the interfacial compatibility, maleic anhydride (MA) and polyvinyl alcohol (PVA) were used to modify LDPE and bamboo-woven structure, respectively. The mechanical properties of the prepared PVA-bamboo-woven structure/bamboo fiber/MA-LDPE composites were greatly improved. The bamboo plastic composites were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, water contact angle (WCA) test and mechanical property test. The results showed that the bamboo-woven structure/bamboo fiber/MA-LDPE composite has superior properties at 45% bamboo fiber content. The tensile strength reached to 33.842 MPa, which was increased by 65.01% compared to the bamboo fiber/MA-LDPE composites, and the bending strength reached to 36.6585 MPa increased by 81.46% in relation to the bamboo fiber/MA-LDPE composites. In addition, even a large number of hydrophilic bamboo fibers and bamboo-woven structure were carried by the composites, a good hydrophobicity was still maintained and the WCA reached to 93.71°. The composites with excellent mechanical properties and hydrophobicity provided a reference for the use of bamboo fibers in environmentally friendly packaging materials. [ABSTRACT FROM AUTHOR]

This paper reports enhanced high-temperature piezoelectric properties of Bi(Zn0.5Ti0.5)O3-modified BiFeO3-BaTiO3 (BF–BT-xBZT) ceramics prepared by two-step sintering method. The resultant ceramics show a symmetrical transition from a rhombohedral–pseudo-cubic (R-PC) phase coexistence to main PC phase with the increase of x, whose R-PC fraction (CR/CPC) is 53.3/46.7, 52.9/47.1, 50.2/49.8, 27.4/72.6, 15.3/84.7 when x = 0, 0.005, 0.01, 0.03, 0.05, respectively. The modification of BZT inhibits the grain growth, reduces the leakage current and gradually drives ferroelectric to relaxor transition. Optimal piezoelectric properties: d33 = 193 pC N−1, Pr = 20.6 μC cm−2, TC = 503 °C and kp = 36% achieved at x = 0.01 composition, which is due to the synergistic effect of an appropriate CR/CPC ratio, improved insulation and good polarization performance. In addition, the depolarization temperature Td is close 280–312 °C, and the high-temperature d33 further increases to 286–347 pC N−1, which shows a good application prospect of lead-free piezoceramics at high temperature. Our work also confirms that the addition of (Zn0.5Ti0.5)3+ and two-step sintering method are an effective and convenient strategy to improve the high-temperature electrical performance of BiFeO3–BaTiO3 based lead-free ceramics. [ABSTRACT FROM AUTHOR]

In this paper, anhydrous porous CuF2 with a micro-nano-hierarchical structure has been successfully fabricated via a precipitation method and a following solid-state reaction process. Scanning electron microscopy, transmission electron microscopy and N2 adsorption–desorption isotherms results confirm that the prepared porous CuF2 bulks are composed of loosely packed nanoparticles with a size range mainly between 30 and 50 nm, forming a micro-nano-hierarchical structure and possessing a large specific Brunauer–Emmett–Teller surface area of 24.93 m2 g−1. The porous CuF2 exhibits an outstanding initial discharge capability of 523 mAh g−1 at 0.1C and a superior rate capacity of 403 mAh g−1 at 5C with a cutoff voltage of 1.5 V versus Li/Li+. Moreover, electrochemical impedance spectroscopy, cyclic voltammetry and galvanostatic intermittent titration technique results verify porous structure can decrease the charge transfer resistance and boost the Li+ diffusion coefficient in CuF2. The method proposed in this work could be potentially used to synthesize other metal fluorides for high-performance lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Fiber-reinforced polymer (FRP) composites are expected to serve as reinforcement materials for coastal and island infrastructure due to their high strength, lightweight, and good corrosion resistance. However, the performance of FRP bars as reinforcement materials in long-term service in the marine environment is also subject to deterioration. Therefore, for improving the durability performance of FRP bars, it seems necessary to understand their degradation behavior. This paper first analyzes the deterioration mechanisms of the fibers, resins, and fiber–resin interfaces that make up the FRP bars under the action of seawater/salt solution, seawater sea-sand concrete pore solution/alkali solution, and stress-marine corrosive environment coupling, respectively, and further investigated the mechanical property degradation of FRP bars under the action of various factors, including interlaminar shear strength, tensile strength, and bond strength with concrete. The degree of degradation of FRP bars exposed to the offshore environment was found to be more sensitive to the magnitude of alkalinity and stress levels; GFRP bars were more resistant to seawater corrosion than BFRP bars. Moreover, the long-term mechanical properties of FRP bars were predicted, and the predicted result is more conservative than the field data. Based on the summarized and analyzed results of this review, recommendations for future work are presented, also for a comprehensive and better understanding of the degradation behavior of FRP bars. [ABSTRACT FROM AUTHOR]

Diamond has been widely used as reinforcing phases in diamond tools and thermal management materials owing to its high hardness and thermal conductivity. However, the surface inertness of diamond inhibits the formation of tight bonding between diamond and matrix, leading to performance of diamond-reinforced composites significantly declined. However, the formation of carbide coatings with good wetting on the diamond may serve as a bridge for optimizing the interfacial bonding of composites. Accordingly, Mo2C coatings were prepared by the molten salt method. Key parameters influencing the coating quality were investigated systematically to shed light on the growth mechanism. Using Mo powder as the Mo source, triangular and square etching pits were formed on diamond (111) and (100) surfaces, serving as nucleation sites for carbides. Mo2C grains nucleated and grew to gradually fill the pits. After simultaneous etching and growth, Mo2C coatings completely covered the surface of the diamond, with thicknesses estimated to 410–420 and 550–600 nm for (111) and (100) surfaces, respectively. Features like the growth rate of carbide, as well as the structure of the etching pits and Mo2C coatings, were found all crystal orientation dependent. The thermal shock and oxidation tests confirmed the effectiveness and affinity of as-prepared Mo2C coatings. The paper provides novel insights into the growth mechanism of Mo2C coating on the diamond from Mo powder source, promising for future syntheses. [ABSTRACT FROM AUTHOR]

During the induction heating process, carbon fiber-reinforced polymer (CFRP) exhibits anisotropic magnetic and thermal properties due to changes in fiber arrangement, which affect the variation of the temperature field distribution on the material's surface and reduce the magnetic field utilization rate. Therefore, this paper adopts the CFRP induction heating finite element microanalysis model to improve the heating efficiency of the material and regulate the temperature field distribution reasonably. The study investigates the coupling relationship between the magnetic field's spatial state and the magnetocaloric properties of the fiber texture, analyzing the mapping relationship between the magnetic field state and the material's calorific value and temperature field distribution. The intrinsic correlation between the magnetic field state and the material's magnetocaloric properties on the temperature field distribution is characterized, providing a theoretical analysis basis for designing and optimizing the temperature and magnetic field distribution during the induction heating process of CFRP. The study aims to achieve effective control of temperature field distribution during the CFRP heating process. [ABSTRACT FROM AUTHOR]

Numerous catalysts have been studied and developed to catalyze the decomposition of methane and in this paper, an iron slab is selected as the catalyst to obtain stable Fe3C and C2 during the decomposition of methane. We combine ReaxFF MD simulations and laboratory work to investigate methane decomposition and carburization of carbon atoms. The analysis of XRD and TEM confirms the Fe3C formed after the reaction and demonstrates its microscopic morphology. Simulations reveal that the iron slab accelerates the primary decomposition of CH4 in the meantime promotes the synthesis of hydrogen molecules and the whole carburizing reaction mechanism has been characterized by the formation of Fe3C and diffusion of C atoms which has been described with carburizing depth. Finally, the influence of methane concentration is explored and the result shows that an appropriate enhancement accelerates the carburizing reaction while the excessive increase will inhibit it. [ABSTRACT FROM AUTHOR]

Recent research has demonstrated that the CuFeTe2 compound has interesting physical properties. However, less research effort has been afforded to the study of the stable non-stoichiometric Cu1.1Fe1.2Te2 structure and electronic properties. In this paper, we report the synthesis and electronic properties of the non-stoichiometric (Cu, Fe) co-doped CuFeTe2 (Cu1.1Fe1.2Te2) with a stable single phase. The temperature-dependent resistance and magnetic susceptibility measurements showed an obvious phase transition from a semiconductor to metal when the temperature reached 360 K, revealing a spin-density-wave (SDW)-like state existing in the as-grown Cu1.1Fe1.2Te2, which has a higher SDW transition temperature than that of CuFeTe2. Interestingly, a spectral weight evolution of the angle-resolved photoemission spectroscopy in the study of the electronic structure of Cu1.1Fe1.2Te2 is observed at the same temperature of 360 K. Our work provides a scheme for exploration of novel physical phenomena related to SDW in two-dimensional materials. [ABSTRACT FROM AUTHOR]

The trend toward miniaturized and highly integrated chip packaging has created a pressing need for lead-free solders with high strength, toughness, and conductivity. In this paper, we designed a scheme of Al2O3-modified nanomaterial-reinforced low silver Sn1.0Ag0.5Cu (SAC105) solder matrix. To begin with, a novel amorphous carbon and nickel core–shell structure plating modified on Al2O3 (C/Ni/Al2O3) were prepared by the electroless plating method. Then, the nano-C/Ni/Al2O3 particle as reinforcement phase was mixed into the matrix solder alloy by ultrasonic vibration stirring. Finally, the morphology and relationship between coated carbon, deposited nickel and original solder interface were analyzed. The microstructure and main properties of the modified solders were also investigated. The experimental results suggested that amorphous carbon and nickel film were prepared on the surface of Al2O3 by electroless plating method. The outer layer of nano-Al2O3 was coated with non-uniform thickness of nickel and carbon coatings. The mass percentage of amorphous carbon was about 3.50%. Adding C/Ni/Al2O3 (0–0.5%) into the SAC105 solder matrix resulted in a gradual increase in conductivity and wettability. The strength and toughness of the modified solder alloy improved as well with the adjunction of reinforced phase. The tensile fracture surface exhibited from a mixture of ductile and brittle, characterized by dimples and cleavage surface, to a purely ductile mode consisting mainly of dimples. [ABSTRACT FROM AUTHOR]

In this paper, we proposed rapid laser-induced synthesis of copper micropatterns on the surface of oxide glass from deep eutectic solvents (DESs) consisting of choline chloride, citric or tartaric acid, and copper acetate as the copper plating solutions. It was shown that upon the 532-nm continuos wave laser irradiation, it is possible to increase the deposition rate of copper and create micropatterns with a resistance close to the value of pure metal together with high adhesion to the substrate surface. This metallization method is favorable for the practical use of copper patterns, including in the production of new printable microelectronic devices. Thus, we demonstrated the possibility of copper deposition on arbitrary three-dimensional surfaces. Moreover, the resulting copper micropatterns were tested as working electrodes for non-enzymatic glucose. Finally, the proposed technology can be successfully used for the design and development of sensor platforms for the electrochemical analysis and microelectronic devices. [ABSTRACT FROM AUTHOR]

A new evaporative crystallization method was used to plate copper on water-soluble NaCl particles. Cu(NO3)2·3H2O was crystallized on NaCl particles by the heated ethanol volatilization, and then thermally decomposed to obtain CuO coating which was finally reduced to Cu coating. The affecting factors of coating effect and the influence of copper-plated NaCl particles on the pores structure of infiltrated AlSi12 foam were studied. The thermal oxidation pretreatment of NaCl particles increased the number of oxygen-containing functional groups and the uniform distribution of thermal etch pits, which improved the bonding strength between NaCl particles and Cu(NO3)2·3H2O coating. The addition of Tween-60 and PEG-6000 inhibited the micro-dissolution of NaCl particles in ethanol and promoted the formation of complete CuO coating. Infiltrated AlSi12 foam prepared from copper-plated NaCl particles had a more homogeneous pore structure and smaller pore size deviations than infiltrated AlSi12 foam obtained with uncoated NaCl particles, indicating that copper plating significantly improved the wettability of NaCl particles and AlSi12 alloy melt. This paper presents a new and low-cost surface treatment method, which provides a useful reference for the surface modification and application of water-soluble particles. [ABSTRACT FROM AUTHOR]

Nitrogen doping is an effective way to improve the electrical and catalytic properties of graphene. Here, we used a non-thermal plasma technique with AC rotating arc to prepare nitrogen-doped graphene. This method does not need catalyst and can produce nitrogen-doped graphene in the atmospheric environment by large scale. CH4 as the carbon source and N2 as the nitrogen source, nitrogen-doped graphene was obtained by plasma direct synthesis. The nitrogen content in the product was analyzed by X-ray photoelectron spectroscopy and the doping level was about 1.19 at.%. It was found that H2 and CO2 as carrier gases can change the nitrogen doping type and content. When there was only N2, pyrrolic N and graphitic N were the main forms in the graphene. The addition of H2 improved the selectivity of pyridinic N and pyrrolic N, but decreased the nitrogen doping content. CO2 significantly increased the selectivity of pyrrolic N and increased the nitrogen doping content. In addition, the formation mechanism of nitrogen-doped graphene was briefly described in this paper. The key in this plasma production technology is to understand the effect of carrier gas on nitrogen doping, which is also instructive for mass production in industry. [ABSTRACT FROM AUTHOR]

In the present paper, V2O5-TeO2 glass was prepared by the melt-quenching technique. Crystallization of glass with a vanadium content higher than 35%mol results in an increase in electrical conductivity by a few orders of magnitude and a decrease in activation energy from ~0.40 to ~0.12 eV. In this work, a critical review of existing charge transfer models was presented on the example of V2O5-TeO2 glass and glass–ceramics. Schnakenberg's and Friedman-Triberis' charge transfer models were found to be applicable to both glass and glass–ceramics. Optical phonon frequencies obtained from Schnakenberg's model are in agreement with FTIR studies. Values of activation energies obtained from the Schnakenberg model decrease after crystallization. Friedman-Triberis' model shows an increase in the density of states near the Fermi level from 1019 eV−1 cm−3 in glass, to 1021 eV−1 cm−3 in glass ceramics. Structural studies show that the main crystallizing phase is Te2V2O9 which occurs with the V2O5 shell in glasses with compositions 50–50%mol and 45–55%mol. It is concluded that crystallization results in the reduction of vanadium ions in the remaining glass matrix which leads to an increase in the V4+/V5+ ratio and therefore, an increase in electrical conductivity. [ABSTRACT FROM AUTHOR]

The prediction accuracy of current mainstream machine learning (ML) models depends on regulating many hyperparameters. In this paper, a deep forest (DF) model with a few hyperparameters and a non-excessive dependence on super parameter regulation was applied to the prediction of glass-forming ability (GFA) of bulk metallic glasses (BMGs). Compared with these of the mainstream ML models, including Support Vector Regression (SVR), random forest (RF), gradient boosted decision trees (GBDT), k-nearest neighbor (KNN), and eXtreme gradient boosting (XGBoost), the tenfold cross-validation shows that the determination coefficient (R2) of our suggested DF model is improved by 10.4%–74.2%. Moreover, the parameter Φ obtained by the SHapley Additive exPlanations (SHAP) method analysis can be used to guide the design and development of BMGs. Finally, a design and development of scheme process for BMGs that meets the expected requirements is given via parameter Φ and the constructed DF model. [ABSTRACT FROM AUTHOR]

In recent years, biodegradable porous Zn-based scaffolds employed as bone tissue engineering scaffolds to treat large bone defects have attracted attention of many researchers. Although porous Zn-based scaffolds have acceptable biocompatibility in vivo and more reasonable degradation rates than degradable Mg-based and Fe-based scaffolds, there is still a certain distance between the porous Zn-based scaffolds that have been developed and the ideal bone tissue engineering scaffolds. In this paper, the methods that had been used to prepare porous Zn-based scaffolds were summarized, and the advantages and disadvantages of each method were analysed. The mechanical properties of porous Zn-based scaffolds were reviewed, and the compressive, tensile, and fatigue behaviors of the scaffolds were also discussed. The degradation properties of porous Zn-based scaffolds in vitro were summarized, and the degradation rules were found. Comparing the degradation properties of bulk Zn-based materials and porous Zn-based scaffolds, the degradations of porous Zn-based scaffolds were more deeply understood. In addition, the degradation behaviors of porous Zn-based scaffolds in vivo were also reviewed. The antibacterial properties of porous Zn-based scaffolds were summarized. Reviewing the experimental results of the biocompatibility of porous Zn-based scaffolds in vitro and in vivo, the main factor affecting the biocompatibility was identified, and the reasons for the large gap between the biocompatibility results in vivo and in vitro were discussed. At last, the problems faced by the current porous Zn-based scaffolds used as bone tissue engineering scaffolds were proposed, and the potential solutions to these problems were also suggested. [ABSTRACT FROM AUTHOR]

AA6101 Al alloy is widely used as a high-strength conductive aluminum alloy, and the contents and existence of Mg and Si can influence its electrical conductivity and mechanical properties obviously. In this paper, experiments were conducted to find the optimal Mg, Si additions and Mg/Si ratio and then combined with heat treatment to improve the EC and mechanical properties at the same time. Firstly, considering the proper Mg/Si ratio, two optimal Mg and Si additions were determined: Al–0.7Mg–0.5Si and Al–0.4Mg–0.7Si with EC of 51.5%IACS and 51.4%IACS, and through homogenization treatment, their EC improved to 57.0%IACS and 55.7%IACS, respectively. Then, appropriate Fe was added to further control Si to achieve the balance of EC and mechanical properties. Results showed that for AA6101 Al alloy the ideal Mg/Si mass ratio was 1.4 and high Mg and low Si can obtain good EC and mechanical properties. Besides, it can be found that at low Mg/Si ratio, the alloy conductivity takes longer to reach its peak hardness. So the best performance Al–0.7Mg–0.5Si–0.2Fe alloy was obtained within the range of AA6101 national standard. The EC of Al–0.7Mg–0.5Si–0.2Fe can reach 56.3%IACS, and hardness is 91.3 Hv. Based on the study, a schematic diagram was drawn to analyze the influence mechanisms of Mg, Si and Fe on EC and hardness of AA6101 Al alloy. [ABSTRACT FROM AUTHOR]

The effect of Ru on microstructures, coating texture changes, mechanical properties improvement, and cutting performance enhancement in CVD TiN-TiCN-Al2O3 coated cemented carbide was investigated in this paper. The results show that with the increasing amount of Ru, the mean grain size of the matrix decreases from 1.28 to 0.95 μm. The microstructural refinement of the matrix creates more nucleation sites for coating growth, which further reduces the grain size of the coating. Moreover, the Ru, diffusing from the matrix into the coating, changes the growth direction of partial grains. The coated cemented carbide with 1.5wt% Ru shows the largest hardness of 17.8GPa, which results from the combined influence of the reduction in coating grain size and the decrease in the concentration of TiCN coating {111} texture. In the process of turning 17-4PH stainless steel, due to the improved hardness and plastic deformation resistance of the composite coating, as well as enhanced (104) texture of Al2O3 coating, the flank wear of the coated tool with 0.5wt% Ru is 31.25% lower than that without Ru, which exhibits the best cutting performance. [ABSTRACT FROM AUTHOR]

Selective electron beam melting (SEBM) has been recently employed for additive manufacturing (AM) Al alloys but showing comparatively low hardness and strength. In this work, SEBM technique was employed to additive manufacture an in-situ TiB2 particle reinforced AlSi10Mg composite. With optimized processing parameters, the SEBM TiB2/AlSi10Mg composite showed good surface quality and a high relative density. The as-printed composite exhibited a refined equiaxed grain structure with an average size of 27.7 µm. The eutectic Si phase was mostly spherical and uniformly distributed in the Al matrix, while the nano-sized TiB2 particles were partly agglomerated. The resultant microstructure was associated with the combined effect of the rapid solidification and annealing-like process during SEBM. Additionally, TiB2 particles facilitated grain refinement by enhancing the heterogeneous nucleation and retarding grain growth. The SEBM TiB2/AlSi10Mg composite presented a yield strength (YS) and ultimate tensile strength (UTS) of 103.6 MPa and 165.4 MPa, respectively, with an appreciable elongation of 15% at as-printed state. After a T6-like treatment, the YS and UTS of the composite were further improved to 225 MPa and 316 MPa, respectively, and an elongation of 12% was maintained. This paper shows the potency of SEBM in AM metal matrix composites (MMCs) with both agreeable strength and ductility. [ABSTRACT FROM AUTHOR]

This paper describes the fabrication of biopolymer foams from aqueous solutions of carboxymethyl cellulose (CMC), as well as effective methods for stabilizing CMC foams in aqueous environments so as to prevent their conversion to gels that results from pore collapse. CMC foams were produced easily by lyophilization of aqueous solutions of high molecular weight CMC, but the considerable hydrophilicity of this anionic polyelectrolyte led to rapid pore collapse and gelation of the material upon its contact with liquid water. However, the porous structure of the CMC foam was stabilized in the presence of aqueous solutions of CaCl2. Mechanical measurements showed the foams to be stiffer in the presence of higher salt concentrations. In addition, CMC foams crosslinked with poly(acrylic acid) (PAA), via the residual hydroxyl groups on the CMC scaffold, were stable in liquid water. When covalent crosslinking was combined with the presence of CaCl2, and/or cellulose additives, the resultant CMC foams exhibited excellent aqueous stability for months or longer and withstood multiple compression cycles without loss of mechanical performance (i.e., by maintaining their porous foam structure). These hydrophilic foams absorbed many times their own weight of water (> 30 g of liquid water per gram of foam) and were amenable to ion exchange, absorption/desorption of organic substances and heavy metals, and water uptake at levels that make them attractive materials for applications in water recovery. [ABSTRACT FROM AUTHOR]

The mechanism of microstructure evolution during rapid solidification and the proactive regulation of phase constitution to optimize the micromechanical properties of multicomponent alloys have been the focus of research in recent years. In this paper, the evolution of microstructural growth kinetics and the formation of amorphous phase in CoCrFeNiZr0.5 alloy were achieved by melt spinning technique and electrostatic levitation coupled melt quenching. According to the theory of transient nucleation, the nucleation incubation time of Laves, FCC, Fe23Zr6 and BCC phases with undercooling during rapid solidification of the alloy was calculated. And based on this, the mechanism of phase transition in the process of regular eutectic → anomalous eutectic → nanocrystalline → amorphous composite → complete amorphous structure was discussed and explained. The growth behavior of primary and eutectic phases solidified at different undercoolings was investigated. Combined with melt quenching, the alloy melts were quenched in the superheated state, liquidus, undercooled state and recalescence process. Multiple microstructures, including amorphous structure, amorphous plus nano-eutectic, gradient nano-eutectic and composite structure of primary Laves phase, along with primary eutectic plus secondary quenched eutectic structures were obtained, respectively. Moreover, the shear band and free volume theory were applied to explain the deformation behavior and the discrepant mechanical performance between amorphous composites and amorphous structures. The formation of quenched nano-eutectic and amorphous structure not only improves the hardness of the alloy, but also enhances the fracture toughness. [ABSTRACT FROM AUTHOR]

In this paper, the waterborne aluminum pigments with intelligent anticorrosion properties and bright colors were prepared by encapsulating multifunctional composite layers, which were composed of zeolitic imidazole framework (ZIF) and silica. With the results of the micropores and microcracks generated in the silica layer, the penetration of acidic corrosion into the inner layer caused the ZIF layer to release the linker as the corrosion inhibitor and construct a new barrier on the metal surface due to the high corrosion inhibitor content in ZIF. After the pH response, the highest impedance of the aluminum pigments was up to 4.35 × 105 Ω cm2. The aluminum pigments with the multifunctional composite layers (Al@ZIF-B@SiO2) could maintain stability at pH = 1. Meanwhile, the excellent adsorption and porosity of ZIF were applied to sorb the dye, which endowed the aluminum pigments with bright colors. The functional composite layers on the aluminum pigments eliminated the hydrogen emission, which proved the excellent chemical stability of the prepared samples. The sensitive pH responsiveness of Al@ZIF-B@SiO2 was also testified. [ABSTRACT FROM AUTHOR]