Table of contents

In this paper, the effects of glaze layer thickness on the color properties of copper glaze were investigated, and the related mechanism was also revealed. The results manifest that the glaze thickness would affect the color of copper glaze. The color properties of copper glaze are determined by the phase-separated structure, the distribution of elements and the valence state of copper species. Due to the heterogeneous distribution behavior of the elements, the copper glazes with all thicknesses have three phase-separated structures, which are spherical (top layer), worm-like (interlayer) and nano-porous network-like (bottom layer). Simultaneously, the copper glazes with all thicknesses have three colors, of which the bottom layer of all samples is red. However, the color of the top layer gradually changes from milk white (0.2 mm) to cyan (0.4–0.6 mm) and then to blue (0.8–1.0 mm) with the green body thickness increases. The color of interlayer is the result of the color mixing of the top and bottom layer. A thicker green body thickness (>1 mm) could be propitious for copper glaze to present a superior color performance. This work provides a new and an easily overlooked perspective for the investigation of copper glaze.

In recent years, with the continuous development of solar blind ultraviolet photodetectors, III-V compounds are widely used as semiconductor materials. The nanowire array structure has excellent 'light trapping effect'. However, if the distance of nanowire is too close, the secondary absorption problem of the nanowire will occur. If the distance of nanowire is too far, the number of photocarriers generated in the nanowire array per unit volume will be reduced. Meanwhile, the absorption capacity of the nanowire structure with different shapes is different. Based on this background, we studied the influence of the period and geometry of AlGaN nanowires with different Al components on the optical response properties. The finite time domain difference (FDTD) method was used to compare the quantum efficiency and collection efficiency of AlGaN nanowires with different Al components, we found that the quantum efficiency of the hexagonal nanowire array with Al component of 0.42 is as high as 45%, which is the highest in our structure. At the same time, its cutoff wavelength is at 280 nm, which has excellent solar blindness. Therefore, the study in this paper can provide some theoretical reference for the experiment and preparation of AlGaN photocathode.

A series of α-MoO₃-TiO₂ mixed oxides were prepared by calcining a mixture of the heteropolyacid H₃PMo₁₂O₄₀ and TiO₂ at temperatures ranging from 350 °C to 600 °C. The mixed oxides thus prepared were characterized and tested for the oxidation of cyclohexene by the oxidizing mixture H₂O₂/CO₂. FTIR and XRD characterizations showed that the Keggin structure of H₃PMo₁₂O₄₀ was preserved for calcination temperatures below 400 °C. Above 450 °C, Keggin's structure collapses. XRD analysis revealed that as the calcination temperature increased, more orthorhombic α-MoO₃ was formed. Analysis of the reaction mixture by GC-MS showed that oxidation by the H₂O₂/CO₂ mixture leads to 1,2-cyclohexanediol as the main product and to 2-cyclohexene-1-one and 2-cyclohexene-1-ol as minor products. Oxidation by H₂O₂/CO₂ mixture proved to be more effective than H₂O₂ alone and CO₂ alone. The conversion (69.4%) and the 1,2-cyclohexanediol selectivity (93.2%) obtained over α-MoO₃-TiO₂ mixed oxides, higher than that obtained with TiO₂ monoxide and α-MoO₃ monoxide, suggest a synergistic effect between TiO₂ and α-MoO₃. This efficient and stable catalyst after reuse can be developed for the synthesis of diols.

The energy-level alignment at hybrid organic-inorganic interfaces is decisive for the performance of (opto-)electronic devices. We use ultraviolet and x-ray photoelectron spectroscopy (UPS and XPS) to measure the energy-level alignment of vacuum-sublimed α-sexithiophene (6 T) thin films with HF-etched n-type Si(100) and with Si with a native oxide layer (SiO_x). The 6 T thin films induce a small (<0.1 eV) downwards band bending into both substrates as shown by XPS. The well-ordered growth of 6 T on Si leads to a relatively narrow density of states (DOS) distribution of the highest occupied molecular orbital (HOMO) as shown by UPS. Furthermore, the Fermi-level comes to lie at rather mid-gap position and, consequently, no energy-level bending occurs in the 6 T layer. Structural disorder in the 6 T thin film on SiO_x leads to a broad HOMO DOS distribution and to tailing states into the energy gap. Consequently, downwards energy-level bending (by around 0.20 eV) takes place in the 6 T layer.

In this study, the interface models and nanodroplets wetting models of base asphalt (BA), polyurethane modified asphalt (PU-MA) and polyurethane/graphene oxide composite modified asphalt (PU/GO-MA) with acidic and alkaline aggregates were constructed. The adhesion and debonding effects of modifiers on short-term aged asphalt mixtures were analyzed by molecular dynamics (MD) simulation. The moisture damage resistance of the mixture was evaluated by simulating the wetting characteristics of asphalt and water nanodroplets on the aggregate surface. The contact angle, adhesion work, debonding work and relative concentration distribution can effectively analyse the interface interaction behavior between asphalt and aggregate. The results show that the adsorption effect between aged asphalt and CaCO₃ was stronger, and short-term aging enhanced the interfacial adhesion of asphalt mixtures. Calcite was more hydrophilic, and its resistance to moisture damage was far less than quartz. The difference between the contact angle of water-aggregate and that of asphalt-aggregate can effectively analyze the water sensitivity of asphalt mixture. In addition, different components played different roles in the adsorption of asphalt and different aggregate surfaces. The synergistic analysis of the asphalt-aggregate interface and the asphalt nanodroplet-wetting aggregate surface can more comprehensively reveal the variation principle of asphalt parameters and nanoscale properties of asphalt mixtures.

Developing lubricants with good electrical conductivity and good tribological properties is necessary for the power equipment. Here, niobium selenide (NbSe₂) and boron nitride (BN) were employed to act as additives to fabricate the lubricating greases with superior electrical conductivity and tribological properties. The lubricating grease containing different concentrations of additives were synthesized and their conductivities were measured by a volume resistance meter at the room temperature of about 25 °C. The tribological properties of the lubricating greases were also investigated and the worn surfaces were characterized in detail by scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS) and Raman spectroscopy to analyze the lubrication mechanism after friction test. The results showed that NbSe₂ could effectively reduce the volume resistivity by ten times as compared with the base grease. Tribological tests showed that when the concentration of NbSe₂ was 2 wt%, it could reduce the COF and wear scar width by 23.5% and 12.8% under 150 N and 5 Hz, indicating 2 wt% NbSe₂ doped lubricating grease exhibited the outstanding tribological properties. In addition, based on the analysis of the wear surfaces, the superior tribological properties of NbSe₂ grease were attributed to the effective lubricating film generated on the friction surface, which played a key role in reducing friction and anti-wear.

Co-cure adhesive joints are preferred by various industries, namely, automobile, marine and aerospace, to join two surfaces in structural applications, as a useful replacement for mechanical fastenings. The present work focusses on the mechanical properties and free vibration behaviour of co-cured glass fiber compositesreinforced with glass powder. In the course of the experimentation, the adhesive is being reinforced concurrently with glass powder in four different weight percentages, such as 0%, 0.5%, 1%, 1.5% and 2%. The mechanical testing results reveal that the addition of 1.5% of glass powder to the epoxy could relatively help in increasing the tensile strength and flexural strength of the co-cured glass fiber composites respectively to the degree of 11.68% (364.29 Mpa) and 24.75% (256.16 Mpa). The Single lap shear results show that the 0.5% glass powder reinforcement significantly increases the shear strength of the cocured glass fiber composites by 20.91% (19.31 Mpa). Furthermore, the free vibrational study of 1.5% co-cured composites shows that they have a higher fundamental natural frequency than the glass powder reinforced co-cured composites that have a lower weight percentage. Furthermore, the addition of glass powder to the co-cured composites helps in increasing the damping factor of the composites due to the glass powder agglomeration. Neat and glass powder reinforced co-cured samples are further analysed afterwards, using the mechanical and shear test by scanning electron microscopy.

The dispersion and orientation of three different montmorillonite clay nanoparticles embedded in nitrile-based nanocomposites were examined in the current study. Maleic anhydride was grafted onto a nitrile structure for the purpose of enhancing compatibility, and the resulting nanocomposites were investigated. The grafting of maleic anhydride seemed to have a pronounced effect, leading the structure to a near-exfoliation state. Using energy dispersive x-ray spectrometer, the state of distribution of layered silicate clusters in the nanocomposite was assessed, and it was observed that maleic anhydride provided a reduction in the size of agglomerations and enhanced the homogeneity of the system. The intercalation and delamination of the layered silicates over grafting were validated by transmission electron microscopy. Inter-lamellar spacing measurements were found to correlate perfectly with x-ray data. On the other hand, the alignment of the clay nanoparticles was examined by small angle x-ray scattering. A 3D-orientation approach was developed based on the scattering stereographs.

Composite sandwich structures are widely used in a multitude of fields owing to their excellent properties, such as light weight and high strength. In this study, a series of hexagonal-core sandwich panels were integrally fabricated by three-dimensional (3D) printed continuous fiber reinforced thermosetting epoxy composites. The influence of the scaling effects that is, the side length and layer thickness on the compression performance of these structures was studied. The experimental results showed that the specific strengths of three different hexagonal-core sandwich panels with different side lengths of 5 mm, 10 mm and 20 mm side lengths is roughly maintained at 0.018 MPa/(kg m⁻³). In addition, doubling the wall thickness of the hexagonal core increases the compressive strength by only 38.9%. The performance characteristics of these hexagonal-core sandwich panels, which change with size, can provide a reference for designers and can be used for the preliminary prediction of the structural strength.

This paper investigates the bubble deformation in bubble growth using a self-made in situ visual injection molding device. The results show that the deformation degree of independent bubbles is kept within 0.015. Under the frame rate of 25 frames per second (FPS), it is found that adjacent bubbles with the same average diameter simultaneously pass through the deformation critical point, while adjacent bubbles with different average diameters can't pass through the critical deformation point at the same time. The interaction in the process of adjacent bubble growth is simulated by finite element software, radial migration of bubbles is suppressed, the hoop stretch of bubbles is enhanced, and the deformation sequence of adjacent bubbles is determined by bubble radius and bubble pressure. On the basis of the bubble influence zone model and the bubble deformation model, a bubble deformation response model is established, used to reflect adjacent bubbles' deformation response speed.

Polymer-infiltrated zirconia-ceramic composite (PIZC) comprises a pre-sintered zirconia-ceramic matrix and a polymer. In this work, pre-sintered zirconia-ceramic was infiltrated with varied amounts of methacrylate-based polymer. Therefore, this paper reports the effect of polymer amount on the mechanical behavior of PIZC at 1100 °C–1300 °C pre-sintering temperatures. Conventional mechanical tests were performed to obtain the elastic modulus and fracture toughness while Vickers micro-indentations were employed to extract the Vickers hardness. Advanced mechanical behaviour analysis was characterized by plastic deformation resistance, elastic and plastic deformation components and brittleness index. Increasing the amount of polymer from 0 to 42% led to the corresponding decrease in elastic modulus, hardness and fracture toughness by at least 78, 85 and 75%, respectively. As the temperature was increased, both elastic modulus and hardness increased while the fracture toughness initially increased but decreased at higher temperature. Mechanical properties and polymer amount were well modelled by connected-grain models which usefully explained the densification process occurring at higher temperatures. Plastic deformation resistance and component and brittleness index confirmed better plastic properties for PIZC at higher polymer amounts and lower temperature. Therefore, in order to utilize the plastic properties of PIZC during the CAD/CAM process, these findings recommended the processing of PIZC at not-lower-than 26% polymer amount and 1100 °C, which could greatly facilitate its precision ductile machining mode realization. Finally, the results provide a technical guidance for the selection of appropriate polymer amount when fabricating dental restorations from this novel ceramic-composite.

Healthcare-associated infection through transmission of pathogenic bacteria poses a huge threat to public health. One of the main transmission routes is via contaminated surfaces, including those of medical devices, and therefore significant efforts are being invested in developing new surface decontamination strategies. This includes visible light-based approaches, which offer improved compatibility with mammalian cells but lower germicidal efficacy with respect to UV-light. This study investigates the potential to enhance the antimicrobial efficacy of 405 nm light for surface decontamination through use of a photocatalytic TiO₂-doped elastomer, elastomers being selected due to their wide use in biomaterials. Poly(dimethylsiloxane) (PDMS) was doped with TiO₂ nanoparticles and the surface elastomer etched to expose the embedded nanoparticles. As etching results in increased surface roughness, samples with control nanoparticles (SiO₂ and Fe₃O₄) were also investigated to decouple the effects of roughness and photoinactivation upon bacterial attachment and inactivation. Characterisation by SEM, AFM and contact angle analysis confirmed that etching produced a rougher (39.3 ± 15.3 versus 5.11 ± 1.29 nm RMS roughness; etched versus unetched TiO₂-PDMS), more hydrophobic surface (water contact angle of 120 ± 2.5° versus 110 ± 1.0°; etched TiO₂-PDMS versus native PDMS). This surface, rich in exposed photocatalytic TiO₂ nanoparticles, allows direct contact between contaminating bacteria and nanoparticles, enabling ROS generation in closer proximity to the bacteria and consequent enhancement of visible light treatment. Incorporating TiO₂ into PDMS significantly improved the photoinactivation efficacy (mean bacterial count for light-treated samples normalised to untreated samples of 0.043 ± 0.0081) compared to PDMS alone (0.19 ± 0.036), when seeded with Staphylococcus aureus and exposed to 405 nm, 60 J cm⁻² light. However, photoinactivation efficacy was significantly (p < 0.001) enhanced by etching the TiO₂-PDMS surface (0.015 ± 0.0074), resulting in greater photoinactivation than that obtained for etched (47.0 ± 14.5 nm RMS roughness), non-photocatalytic SiO₂-PDMS (0.10 ± 0.093). Results suggest this doping and etching strategy shows significant potential for facilitating decontamination of elastomer-based biomaterials.

Providing better biodegradable materials for medical applications has always been an important premise for improving the therapeutic effect of clinical diseases. The Poly (butylene succinate) (PBS) and Sodium alginate (SA) composites were prepared using melt blending technique. Fourier transform infrared spectroscopy (FTIR), scanning electron microscope-energy dispersion spectrum (SEM-EDS), mechanical properties, water contact angle, thermal properties, and in vitro degradation and cytotoxicity tests were determined to evaluate the properties of the composites with a varied SA proportion of 5%, 10%, 15%, and 20%. The FTIR and SEM-EDS results confirmed the successful preparation and microphase distribution of the composites. With the increasing in SA loading, the distribution of the filler became unevenly gradually from evenly, the Young's modulus increased first and then decreased, the tensile strength and elongation at break decreased gradually, the hydrophilicity, in vitro biodegradability increased, thermostability decreased, and the Tm, Tg, and crystallinity of the composites did not change significantly. The composite with 10% SA loading has uniform dispersion of the filler, the highest Young's modulus (1091.21 MPa), mild hydrophilicity (θ = 88.40°), an adequate thermal processing temperature range (110 °C–200 °C), and has good biodegradability and biocompatibility with no significant deleterious impact on the cell membrane, lysosomal membrane, cell proliferation, cell apoptosis, cytoskeleton, or intracellular reactive oxygen species levels. It can be used as a biodegradable material for medical applications such as suture anchors.

The current research explores the possibility of reinforcing massively available, less utilised, low-cost agro-residue fibres in an epoxy matrix to create a new tribo-material. This study focuses on determining the three-body abrasive wear behaviour (volume loss and specific wear rate (SWR)) of natural cellulosic pigeon pea (PP) stalk fibre reinforced epoxy composites. Further, abrasive wear characteristics of untreated and treated E/PP20 (20 wt.% PP stalk fibre-reinforced epoxy) composites were analysed using Taguchi and ANOVA techniques. Untreated and treated biocomposite specimens were developed using the hand lay-up (open mould) technique. At 11.77 N, 23.54 N, and 47 N loads, the SWR of untreated E/PP20 composite was reduced by almost 5.03%, 3.68%, and 22.30% compared to epoxy specimens. Results of the untreated E/PP20 composite showed that the applied load was the main contributing parameter (54.72%), followed by sliding distance (21.82%) and sliding speed (15.31%). Results of the treated E/PP20 composite showed that the applied load was the main contributing parameter (48.96%), followed by sliding speed (26.24%) and sliding distance (20.78%). The regression model predicted the SWR with a pooled error ranging from 2.37% to −17.77% for untreated composite and 9.87% to −11.49% for treated composite, respectively. The alkali-treated E/PP20 composite exhibited better abrasive resistance than the untreated E/PP20 composite. Scanning electron microscopy images of the treated composites showed good fibre adhesion with the matrix. In addition, the surface of the treated composite showed no fibre pullout or ploughing compared to that of the untreated composite. Surface topography revealed the formation of more craters on the surfaces of the untreated composites and small-sized dispersed craters on the treated composites.

The Chevrel phase (CP) (Mo₆S₈), which is used as an electrode material in Mg rechargeable batteries, has a capacity limit owing to ion insertion and trapping. To address this problem, we modify the wire structure of the CP. Mo₆S₃I₆ nanowires, in which iodiene is substituted for Mo₆S₉ nanowires as infinite CP structures, can be synthesized in various ways. When synthesizing stoichiometrically, an unwanted secondary phase may appear. We solved these problems by reducing the synthesis time. Electrochemical analysis was performed using these nanowires as an active material in Mg batteries.

In order to endow pavement materials with environmental protection properties such as automobile exhaust purification, an environmentally friendly micro-surfacing material with exhaust purification was prepared. Functional materials with photocatalytic activity were prepared by sol-gel method. The best preparation scheme of composite modified asphalt was determined by comparative test. The mix proportion of micro-surfacing mixture was designed to determine the optimal preparation process of micro-surfacing. Based on rutting test, wet wheel wear test and pendulum test, the road performance of protective environmental micro-surfacing with exhaust purification function is studied. An exhaust gas purification test equipment is improved to determine the test method and analyze the exhaust gas purification performance of protective environmental micro-surfacing materials. The results showed that when the molecular weight ratio of Ti : N : Fe was 1 : 0.7 : 0.005, the photocatalytic performance of the prepared environmental functional material with tail gas purification effect was the best. The availability of photocatalytic materials is increased, and the photocatalytic performance is the optimum. When 3% functional materials and 5% SBR latex are used as composite modifier of emulsified asphalt, the consistency, cracking resistance and high temperature performance of composite modified emulsified asphalt are the optimum. The micro-surfacing mixture prepared with 7% oil-stone ratio and 6%–7% external water has good high temperature stability, water stability and skid resistance. When the molecular weight ratio of Ti : N : Fe is 1 : 0.7 : 0.005, the HC purification efficiency reaches 12%, the CO purification efficiency reaches 15%, and the NO_X purification efficiency reaches 30%, which has good road performance and exhaust purification effect.

In this paper, Mg(OH)₂ was prepared by the diaphragm electrolysis method using bischofite (MgCl₂·6H₂O). The influence of electrolysis process conditions such as current density, electrolysis temperature and electrolyte concentration on powder particle size is discussed. The electrolytic product Mg(OH)₂ powder was characterized by laser particle size analysis, XRD, SEM, BET, XRF, and DSC-TGA. The results show that the particle size of Mg(OH)₂ powder first increases and then decreases with increasing current density and reaches a maximum D50 value of 20.1 μm at a current density of 0.04 A cm⁻². The Mg(OH)₂ powder particle size first decreases, then increases and then decreases with increasing electrolysis temperature, at an electrolysis temperature of 60 °C and 70 °C, the particle size reaches a maximum D50 value of 23.8 μm and a minimum D50 value of 7.7 μm, respectively. The Mg(OH)₂ powder particle size first increases and then decreases with increasing electrolyte concentration and reaches a maximum D50 value of 22.3 μm at an electrolyte concentration of 0.7 mol l⁻¹. The Mg(OH)₂ powder prepared at a current density of 0.3 A cm⁻², electrolyte concentration of 0.3 mol l⁻¹ and an electrolysis temperature of 30 °C shows an average particle size of 13.8 μm, a purity higher than 98.66%, and a sheet-like structure. The surface area is 58 m² g⁻¹. The Mg(OH)₂ powder can be decomposed at 300 °C–400 °C and calcined at 400 °C for 2 h, through SEM and Scherrer formula calculation, the calcined product is nano-MgO powder with good crystallinity.

Metal-organic framework MIL-101(Fe) was deposited successfully on g-C₃N₄ templates under solvothermal treatment. The results of XRD, FT-IR, and SEM measurements revealed the growth of MIL-101(Fe) crystals on g-C₃N₄ to fabricate the g-C₃N₄/MIL-101(Fe) hybrid. The photocatalytic ability of g-C₃N₄/MIL-101(Fe) was examined through the photodegradation performance of paracetamol in an aqueous solution under visible light irradiation. Among the samples, 0.5CN-M, standing for 0.5 g of g-C₃N₄ used for fabrication of g-C₃N₄/MIL-101(Fe), showed the best photocatalytic ability when degraded about 34% of paracetamol in water. The effective photocatalytic performance of g-C₃N₄/MIL-101(Fe) than that of MIL-101(Fe) might result from the high surface area of MIL-101(Fe) and the formation of heterojunction layer between this MOF and g-C₃N₄.

The characterisation of dielectric-semiconductor interfaces via Kelvin probe surface voltage and photovoltage has become a widespread method of extracting the electrical properties influencing optoelectronic devices. Kelvin probe offers a versatile, contactless and vacuum-less technique able to provide useful insights into the electronic structure of semiconductor surfaces. Semiconductor theory has long been used to explain the observations from surface voltage measurements, often by making large assumptions about the characteristics of the system. In this work I report an updated theoretical treatment to model the results of Kelvin probe surface voltage and photovoltage measurements including four critical mechanisms: the concentration of charge stored in interface surface states, the charge stored in different locations of a surface dielectric thin film, the changes to effective lifetime and excess carrier density as a result of charge redistribution, and the non-uniformity of charge observed on most large scale thin film coatings used for passivation and optical improvement in optoelectronic devices. A full model is drawn and solved analytically to exemplify the role that these mechanisms have in surface voltage characterisation. The treatment in this work provides crucial understanding of the mechanisms that give rise to surface potential in semiconductors. As such this work will help the design and development of better optoelectronic devices.

This paper mainly investigates the area-dependent gain and noise characteristics of mid-wavelength infrared (MWIR) Hg_0.7Cd_0.3Te planarelectron avalanche photodiodes (e-APDs) operated at 80 K. The 10-μm-radius diode exhibits low dark current in the magnitude of 10^–13 A below −5.5 V, high gain up to 1270 at −10 V, and low excess noise factor between 1 and 1.2. The optimal performances are compromised by tunneling current, which should be further suppressed. Studies on variable-area diodes show that larger diodes have a reduced gain due to a smaller contribution from edge gain, as well as an increased 1/f noise and corner frequency due to higher defect density. From the gain and noise perspectives, HgCdTe e-APDs with smaller junction areas are more suitable for focal plane array (FPA) applications.

We fabricated organic resistive random-access memory (RRAM) devices using a low-cost solution-process method. All the processes were performed at temperatures below 135 °C under ambient atmospheric conditions. The RRAM resistive switching layer was formed from a polymer-fullerene bulk heterojunction using poly(3-hexylthiophene-2,5-diyl) (P3HT) and (6,6)-phenyl C61 butyric acid methyl ester (PCBM). The fabricated organic RRAM device exhibited typical nonvolatile bipolar resistive switching behavior with an ON/OFF ratio of ∼40, but it provided a low endurance of 27 cycles. Therefore, for enhanced stability, simple UV–Ozone (UVO) treatment was applied to the P3HT:PCBM organic bulk heterojunction layer. The organic RRAM device with UVO treatment exhibited an enhanced performance with an ON/OFF ratio of ∼400 and an endurance of 47 cycles. In addition, complementary resistive switching behavior was observed. The conduction mechanisms of the organic RRAM device were investigated by fitting the measured I–V data to numerical equations, and Schottky emission and Ohmic conduction were the main conduction mechanisms for the high-resistance and low-resistance states for the RRAM device with or without UVO treatment.

CdSe single crystal with good optic properties is great candidates for optical devices. In this paper, CdSe single crystal was grown by the modified vertical unseeded vapor sublimation method with the diameter of 36 mm and the length of 40 mm. The quarter wave plates of CdSe single crystal with size of 20 mm × 20 mm × 3 mm was cut along the (001) orientation. The transmittance of the CdSe wave plate was about 69% in the range of 8–14 μm, where the absorption coefficient was about 0.04 cm⁻¹. The phase delay was 90.71176° at 12.4 μm, which less than 5%. This work disclosures a high-quality and large size wave plate of CdSe single crystal, such wave plate has wide application prospects in mid-infrared.

This paper addresses the problem that the microstructure model of magnetorheological fluid established by traditional single-chain or multi-chain dense rows is unable to accurately describe the rheological behavior and the sudden change of macroscopic mechanical properties under the action of an applied magnetic field, and analyzes the stable cluster-like structure formed by a specific volume fraction of magnetorheological fluids in a micro-narrow channel under the action of external magnetic field and extrusion pressure. This paper also establishes the equations of motion and dynamics of magnetic particles under the action of external magnetic field, analyzes the dynamic evolution of particle microstructure, performs numerical simulations of two-dimensional chaining using Matlab, and establishes a microscopic observation test bench for comparison and verification; and it establishes a model of complex cluster-like structure of magnetorheological fluids body-centered cubic, and analyzes the system energy, stability and force of the body-centered cubic structure based on the minimum system energy theory and Hertzian contact theory; and further establishes a shear yield stress model based on the body-centered cubic microstructure to analyze the macroscopic mechanical properties of magnetorheological fluids, thereby enriching the theoretical system of extrusion strengthening of magnetorheological fluids in the microscale.

In response to the inadequacy of experimental methods to explore the effect of doping modification on the performance of AgNi contact materials, the Ag/Ni interface simulation model was established based on the first-principles density functional theory to study the interfacial stability and electronic structure of Ag/Ni with Co-doped and Mo-doped. The stability at the interface can directly affect the anti-melt welding performance of AgNi contact materials. The doping can enhance the interfacial bonding stability of Ag/Ni, the hybridization of Ag and Ni orbitals and the bonding strength of Ag-Ni metal bonds, among which the Mo-doped Ag/Ni has the best stability. The contact materials were prepared by powder metallurgy method. Wettability test and electrical contact performance test were conducted on AgNi contacts before and after doping. It was found that Co and Mo doping improved the anti-melt welding performance and anti-arc erosion performance of the intrinsic contact materials, which verified the simulation conclusions. The doping of Mo in AgNi contacts resulted in a substantial reduction of melt welding force and a significant reduction of material loss, which had the most obvious improvement effect on the contact materials.

This research aims to develop films from natural materials to be used as seasoning packaging for instant noodles. Natural materials such as bananas and konjac are used as raw materials for film-forming. There were 27 formulations of film-forming, including 9 formulas from the banana starch film, 9 formulas from banana starch blended with konjac powder 0.5% w/w, and 9 formulas from banana starch blended with konjac powder 1.0% w/w. The mechanical and physical properties of various formulation films were tested. When selecting a formulation film that meets the packaging requirements for 2 formulations by selecting one banana starch film and one banana starch film blended with konjac powder, it was found that the film formula B4Gly20 (banana 4% W/V and glycerol 20% V/V) and formula K05/4Gly20 (konjac 0.5% W/V blended with banana 4% W/V and Glycerol 20% V/V) have the best fit. They had properties close to specifications such as thickness and water permeability, not significantly different at 0.05%, and high tensile strength of 4.015 and 5.172 N.mm⁻². The flexibility was 27.67 and 22.22 percent, and the water vapor permeability was 0.0063 and 0.0021 g. hr⁻¹.cm ^-2, respectively., resistance to acidic solutions, and can be formed into strong packaging film, etc. When applying these two film formulas to the seasoning packaging of instant noodles, it was found that both film formulations did not prevent moisture in the air. The film formula B4Gly20 effectively prevented oil leakage. And also, B4Gly20 was more resistant to oxygen penetration into the cooking oil than K05/4Gly20 formulation film, but film formulation B4Gly20 was dissolved in hot water 100 ± 10 °C slower than K05/4Gly20. The results showed that the film formulation B4Gly20 was suitable for application in the seasoning packaging of instant noodles.

In recent years, many scholars have paid attention to wear-resistant coatings for shield machine cutterheads due to their very high consumption rates. Among these coatings, nickel-based tungsten carbide (Ni-based WC) is one of the best, showing both corrosion resistance and wear resistance. However, to further improve the wear resistance of such coatings, there are still numerous issues that need to be resolved. Herein, a new method, distinct from conventional methods, is presented. Specifically, the brittle phase W₂C is not widely regarded as the main wear-resistant phase, but we were surprised to find that careful adjustment of its rigid structure can yield satisfactory results. Experimental results and first-principles simulations have indicated that the friction coefficient and weight loss of a coating with a suitable distribution of W₂C are only half of those of a traditional Ni-based WC coating (about five times higher than those of the substrate), which can mainly be attributed to the excellent thermal expansion coefficient and hardness of the W₂C phase. As we expected, the surface morphology of the material after wear revealed that the suitable W₂C layer has a well-defined friction morphology. We hope to provide new ideas for the study of Ni-based WC coatings in shield machine cutterheads.

The transparent InGaZnO (IGZO) film was fabricated on the surface of PZT film by photochemical sol-gel method, hence more UV light can penetrate IGZO film reaching the IGZO/PZT junction and produce photo-induced charge carrier to obtain a high photocurrent. To decrease the crystalline temperature of PZT film, and simplify the fabrication process, the UV photochemical treatment of IGZO and PZT happened at the same time. During photochemical process, the organic agents of both IGZO and PZT gel film were decomposed greatly, forming an active metal-oxygen bond, which facilitate crystallization at a low temperature. The obtained IGZO film show a uniform surface with homogeneous particles, the obtained Pt/IGZO/PZT/LNO hetero-structure shows a good photoelectric property.

Metal oxide nanoparticles were fabricated by membrane emulsification using alumina through-hole membranes with different hole size uniformity. Hole size of alumina through-hole membrane used for membrane emulsification and the size of obtained nanoparticles were evaluated by SEM observation, and the relationship between the uniformity of hole size and the size distribution of the obtained nanoparticles was investigated. As a result, nanoparticles with higher size uniformity were obtained when the RSD (relative standard deviation) of hole size was 3.8%. This indicates that the hole size uniformity of the emulsification membrane is important for the fabrication of droplets and nanoparticles of uniform size by membrane emulsification.

To investigate the impact of initial cracks on the fatigue performance of single lug and yoke joints, fatigue testing was performed for defective welding joint models. The crack extension behaviors were investigated based on the theories of fracture mechanics using ANSYS-FRANC3D interactive technology, and the effects of the initial crack location, morphology pattern, and surface angle on fatigue performance were determined. The results showed a fatigue failure mode in which the crack extended along the welding line for single lug and yoke joints. The fatigue life was shorter when the initial crack was in the corner of the single lug plate. Moreover, the crack growth rates during the early stage of crack extension varied significantly with different initial crack morphology patterns. However, the crack growth rates during the later stages were similar to one another. The remaining fatigue life increased with the shape ratio for the same crack depth. Finally, the crack growth rate was the fastest, and the remaining fatigue life was the shortest when the initial crack surface angle was inclined toward the stress concentration area.

Alloy steel components can be subjected to serious damage from a variety of conditions during the industrial production procedures, such as wear and fracture failure. Therefore, the preparation of gradient-reinforced layers on the surface of the alloy steel was considered an effective technique to improve the performance. Along these lines, a 40Cr alloy steel, which was commonly used in industry, was systematically investigated in this work. The nano TiC ceramic material was selected in the hard phase. In this work, continuous-wave laser was used to fabricate gradient reinforced layers, which provided a technical reference for the development of protective reinforcement layers for alloy steels with excellent mechanical properties. A dense structure was formed inside the nano TiC gradient reinforced layer, which has a lower friction coefficient (0.25) and wear loss weight (23 mg). The height of the surface material loss under a heavy load wear environment (187 μm) was lower than that of a bare 40Cr alloy steel sample (1116 μm). The impact energy of the nano TiC gradient reinforced layer (75.27 J cm⁻²) was higher than that of a bare 40Cr alloy steel sample (15.25 J cm⁻²). Both the wear behavior and impact toughness strengthening mechanism of the nano TiC gradient reinforced layer were revealed.

Ultrafast nanocalorimetry, in combination with high-speed IR thermography, is used to measure the interfacial thermal conductance (ITC) of the thermal contact of metal microdroplets with a solid during fast melting (including laser heating). IR thermography and membrane nanocalorimetry were used to measure the temperature difference at the membrane/sample interface during the melting and crystallization of aluminium alloy (AA7075) microdroplets (20 μm in diameter) over a wide range of heating and cooling rates (up to 10⁵ K s⁻¹). This is the first time ITC has been measured at such high heating and cooling rates with this new method. We found that the interfacial temperature difference reaches about 80 K during the solidification of microdroplets during laser heating. This result is significant for understanding various industrial laser-assisted processes. It has been established that ITC measured for AA7075 microdroplets gradually increases by an order of magnitude during melting in the range from the solidus temperature to the liquidus temperature of the alloy. This unusual behavior of ITC during melting can be important for understanding and optimizing laser-assisted additive manufacturing processes.

Wear under high temperature is one of the mechanisms of die failure. Therefore, wear resistance at high temperature is an important parameter for selecting die materials. In this work, the wear resistance of SDHA austenitic steel (6Mn14Cr3Mo2Si1V2 steel) and 4Cr5Mo2V martensitic steel at 400 °C–700 °C was investigated using a friction and wear tester. The wear behaviour and oxide type were investigated using a scanning electron microscope (SEM) and by X-ray diffraction (XRD), respectively. The results show that the oxides on the worn surface at the test temperatures are Fe₂O₃ and Fe₃O₄. With increasing test temperature, from 400 °C to 700 °C, the wear volume of the two steels initially decreases and then increases. Between these two temperatures, the wear volume of SDHA austenitic steel increased from 29.7 mm³ to 81.2 mm³, a 173.4% increase. The wear volume of 4Cr5Mo2V martensitic steel increased from 34.7 mm³ to 134.7 mm³, a 267.4% increase. Hence, SDHA austenitic steel has better wear resistance than 4Cr5Mo2V martensitic steel. This is attributed to excellent hardness stability at high temperature. The coarse M₇C₃ carbides in 4Cr5Mo2V martensitic steel cause peeling and delamination of the oxide layer, reducing wear resistance at 700 °C.

In this study, Mg+B wires were prepared by powder in tube method using Nb and Cu tubes as barrier and sheath, respectively, followed by cold drawing. Microstructural, textural, and mechanical properties of the Nb barrier at different drawing strains (ε_d) were investigated. The results showed that the Nb barrier demonstrated a saturation hardness of 159.4 HV. The microstructure of the Nb barrier became elongated along the drawing direction increasing ε_d. Sub-grains existing inside the deformed grains rotated from low-angle grain boundaries to high-angle grain boundaries and developed into new grains. The main textural components of the Nb barrier were {111} γ-fiber and {hkl}〈110 〉 α-fiber. Recrystallized grains exhibited a low maximum orientation distribution function intensity, weak {100}〈110 〉 α-fibers, and strong {111}〈110 〉 γ-fibers as compared to those of the deformed grains. The relationship between the microstructure evolution and mechanical properties of the Nb barrier and the changes in the cross-sectional area fractions of the materials constituting the Mg+B composite wire are discussed. The current study provides details about the misorientation profile inside deformed grains and continuous dynamic recrystallization mechanism of the cold-drawn Nb barrier.

Anisotropic deformation of colloidal particles was investigated under ion irradiation with 4 MeV Cu ions. In this study, 0.5 μm-diameter colloidal silica particles, 0.5 μm-diameter Au-silica core–shell particles, and 15 nm-diameter Au colloids embedding in a planar Si/SiO₂ matrix were irradiated with 4 MeV Cu ions at room temperature and normal incidence. In colloidal silica particles, ion beam irradiation causes dramatic anisotropic deformation; silica expands perpendicular to the beam and contracts parallel, whereas Au cores elongate. Au colloids in a planar SiO₂ matrix were anisotropically transformed from spherical colloids to elongated nanorods by irradiating them with 4 MeV Cu ions. The degree of anisotropy varied with ion flux. Upon irradiating the embedded Au colloids, dark-field light scattering experiments revealed a distinct color shift to yellow, which indicates a shift in surface plasmon resonance. A surface plasmon resonance measurement reveals the plasmon resonance bands are split along the arrays of Au colloids. Our measurements have revealed resonance shifts that extend into the near-infrared spectrum by as much as 50 nm.

This paper proposed the double-pass compression thermal/force simulation experiment to in situ analyze the phase transformation of continuous casting billet during the controlled rolling and controlled cooling process. The genetic relationship between the central segregation of the billet and solute element distribution of the steel plate, and also the genetic relationship of microstructure and mechanical properties between them were experimentally studied. The results show that the microstructure and mechanical properties between the billet and corresponding batch of steel plate have the genetic relationship, and the link of the relationship is central segregation. The phase transformation of supercooling austenite will be affected by the central segregation of Mn and C elements, and the granular bainite abnormal segregation band is the transformation product of Mn and C element segregation region.

Aluminium matrix composites have gained interest recently because they are more efficient, lighter, and less expensive. The purpose of this current study was to examine the effects of various casting operating conditions, including stirring temperature, stirring time, and stirring speed, on the casting process. Determining the optimum processing parameters to achieve significant outcomes could be the most daunting problem while casting a specimen. Box-Behnken design based on response surface methods was used to investigate the effects of stir casting factors on the mechanical properties of AA6063%–4% TiB₂ composites. The response's real value, which includes hardness before heat treatment, hardness after heat treatment, and tensile strength, is reflected in the surface plot created by statistical software. F-ratio is often used in an ANOVA table to examine how operational variables affect properties of the material. Dispersion of the reinforcements mixture has been studied and characterized under scanning electron microscope and x-ray diffraction spectrometer. The optimum temperature, time, and rotational speed were 823.662 °C, 15 min, and 300 rpm. Composite materials made from aluminium 6063 are extensively used in the fabrication of lightweight aircraft components like ribs and fuselages.

Evolution of microstructure and the globularization mechanism of α lamellar for TC21 titanium alloy during multi-directional forging (MDF) were analyzed with the help of OM, SEM, EDS and TEM techniques, FE simulation was also used to observe the above process. The main conclusions are as follows: With the increase of temperature, forging cycle and single pass strain, the fraction of globularization of α lamellar gradually improved. The volume fraction of globularization of α lamellar achieves a high value about 85%, the average grain size of TC21 titanium alloy can be refined to 2 μm through MDFed at 910 °C with strain of 0.69 in 3 cycles. Forging cycle is the most key factor to obtain the ideal microstructure. Increasing temperature and MDFed pass can not only promote the fraction of DRX (dynamic recrystallization), but also achieve uniformity of deformation. The error between simulation and experiment is below 14%. DRX is the major globularization mechanism of the α lamellar during MDF. In the early stage of MDF process, the globularization mechanism is boundary splitting accompanied by CDRX (continuous dynamic recrystallization) and DDRX (discontinuous dynamic recrystallization), which is formed by the β phase into α lamella along the sub-grain boundaries. In the later stage of the process, the globularization mechanism is termination migration, which is caused by elements diffusion due to variant curvature of different position of α lamellar, while a slow process for globularization.

Al₂O₃p/high-manganese steel-matrix composites were successfully fabricated by gravity casting infiltration, with iron powder added in the preforms to adjust the Al₂O₃p fraction. The effects of the iron powder content (38, 48, and 55 wt%) on the microstructures and mechanical properties of the composites were investigated. With the increase in the iron powder content in the preform, the Al₂O₃p fraction decreased (57–38 vol%), while the hardness and compressive strength of the composite gradually increased. The highest compressive strength was 1000.3 MPa (55-wt% iron powder). The highest work hardening rate (55-wt% iron powder) well reflected the synergistic effect between the matrix and reinforcement to prevent dislocation movement. The water glass binder formed thick interface layers between Al₂O₃p and matrix, which transformed the Al₂O₃/metal interface bonding from mechanical bonding to metallurgical bonding. A too thick interface layer deteriorated the mechanical properties of the composites.

Selective laser melting (SLM) technology was employed to manufacture Zn-3%Mg alloy and the effects of the addition of Mg elements on the density, microstructure, mechanical property and corrosion behavior of Zn-based alloy additively manufactured parts was investigated. Experiment results demonstrate that the density of pure Zn-based additively manufactured parts under optimal parameters can be up to 96.7%. With the same parameters, Zn–3Mg alloy was prepared by SLM additive manufacturing technology to obtain additively manufactured parts of Zn–3Mg alloy with the density of 96.0%. Compared with pure Zn, the average grain size in horizontal sections of additively manufactured parts added with 3 wt% Mg reduces from about 21.1 μm to about 2.1 μm and columnar crystals in vertical sections are transformed into equiaxed crystals. The microhardness of Zn–3Mg alloy is 2.6 times higher than that of pure Zn and tensile strengths in both the horizontal and vertical directions of Zn–3Mg alloy are twice as high as that of pure Zn. Moreover, the yield strength of Zn–3Mg alloy under compressive load is more than three times higher than that of pure Zn. After immersing pure Zn and Zn–3Mg alloy in simulated body field (SBF) for 7 days, their corrosion rates tend to be stable, i.e. about 0.13 and 0.09 mm·year⁻¹ respectively, that is, the corrosion rate of Zn–3Mg alloy is about 70% that of pure Zn.

Hole defects are very common in metal plates. The propagation of cracks in engineering structural members will be affected by the holes of the members, which will not only change the propagation direction of cracks, but also have the ability to limit the growth of cracks. Therefore, the study of material fracture crack propagation caused by the distribution of holes and other factors under loading conditions has become a problem that needs to be considered in structural design. The cohesive zone model (CZM) can effectively avoid the singularity problem of crack tip stress when simulating crack growth, and at the same time can clearly show the crack growth path. Based on exponential CZM, the finite element analysis of tensile test for metallic materials with hole defects was carried out. The crack propagation law under constant load was obtained. It was proved that CZM could simulate the crack propagation in metallic materials with holes more accurately. The influence of the pore size, shape, distribution on the crack propagation is discussed. The results show that the smaller the distance difference between holes, the greater the supporting reaction force. The smaller the radius of the hole, the higher the fracture toughness and the maximum supporting reaction force of the metal plate. And it also can be seen that as the number of holes increases, the maximum supporting reaction force and fracture toughness of the metal plate decrease. The use of staggered holes distribution has greater supporting force and better toughness. The research results of this paper provide a theoretical basis and reference for investigating the propagation and propagation of cracks in the process of damage and failure of materials and for structural design and performance evaluation of engineering materials.