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Thermochromic materials have garnered significant attention for their ability to change color in response to temperature fluctuations, offering innovative solutions for smart textiles, fashion, and functional clothing. This review provides a comprehensive overview of organic thermochromic materials and their potential in textile applications. It begins by explaining the fundamental principles and mechanisms of thermochromism, exploring various organic types such as leuco dyes, liquid crystals, and polymers, along with their advantages and limitations in textile applications. The paper delves into aspects such as synthesis methods, compatibility with textile substrates, durability, and washfastness. Recent advancements, including innovative manufacturing techniques and emerging materials, are highlighted, showcasing enhanced performance characteristics. The diverse applications of organic thermochromic textiles, from thermally responsive clothing for comfort and energy efficiency to visual indicators for temperature monitoring in industrial settings, are discussed. Finally, the review offers insights into future trends and prospects for organic thermochromic materials in textiles. This review serves as a valuable resource for researchers, textile engineers, and designers aiming to leverage organic thermochromic materials to create dynamic and functional textiles for the future. [ABSTRACT FROM AUTHOR]

The development of metal–organic frameworks for carbon dioxide (CO2) capture has drawn considerable interest among researchers with MIL-101(Cr) gaining significance owing to its high stability. This paper investigates the one-step synthesis of MIL-101-NH2(Cr) by using guanidine hydrochloride as a mediator under relatively mild conditions (aqueous phase, reaction temperature of 120 °C, and without the use of mineralization agents such as hydrofluoric acid). MIL-101-NH2(Cr) not only exhibited a high specific surface area with a Lewis-base site-rich ligand but also possessed a good CO2 adsorption capacity of 3.96 mmol/g at 1 bar. Furthermore, diethylenetriamine (DETA) was loaded into MIL-101-NH2(Cr) to design a new CO2 adsorbent DETA@MIL-101-NH2(Cr). The loaded material maintained the original structure and also displayed an improved adsorption capacity of 0.29 mmol/g under low (< 0.11 bar) CO2 partial pressure. The absorbents possessed good selectivity, stability, and recyclability which make them ideal candidates for CO2 capture. [ABSTRACT FROM AUTHOR]

In this paper, two hydrated double salts, whose chemical formulas are K2Mn0.15Co0.85(SO4)2(H2O)6 (KMn/Co) and K2Mn0.16Zn0.84(SO4)2(H2O)6 (KMn/Zn), were crystallized via solvent slow evaporation. The structural, thermal, and vibrational properties were explored and discussed. Furthermore, a study of geometric, electronic, and thermodynamic (entropy, enthalpy, and free energy) parameters was performed based on computational calculations. Single-crystal X-ray diffraction indicated that the compounds belong to the family of mixed Tutton salts with monoclinic symmetry, space group P21/c ( C 2 h 5 ), and occupancy factors of Mn0.15/Co0.85 (KMn/Co) and Mn0.16/Zn0.84 (KMn/Zn). Additionally, the intermolecular contacts and total empties in the unit cells were determined by Hirshfeld surfaces and crystal voids, respectively. The two crystals exhibited thermal stability around 333 K (Mn–Co) and 348 K (Mn–Zn). Above these temperatures, endothermic and exothermic events characteristic of dehydration, crystallization, solid–solid transition, and melting are recorded. Furthermore, KMn/Co and KMn/Zn exhibited significant energy densities, making them promising candidates for thermochemical energy storage systems. An energy band gap of 4.13 eV and 4.49 eV was predicted for KMn/Co and KMn/Zn, respectively. These findings are characteristic of insulating materials with major contributions from p orbitals in the valence and conduction bands. Using group theory and density functional theory (DFT), it was suggested that the two compounds have a total of 183 optical modes in the spectral region from 30 to 3600 cm−1. Furthermore, experimental and calculated Raman and infrared spectra showed a good correlation. Our data suggest that the KMn/Co and KMn/Zn salts present promising thermo-structural results, showing that they can be used in heat-storing thermochemical devices due to their low dehydration temperatures, high dehydration enthalpies, and good energy density. [ABSTRACT FROM AUTHOR]

The frequent outbreak of infectious respiratory diseases, such as the recent COVID-19 epidemic, raised the importance of indoor air quality. Removing microorganisms from indoor air is critical to improve indoor air quality. Numerous studies in recent years have been published on developing antimicrobial materials and technologies for antibacterial and antiviral applications. This study critically reviews the recent antimicrobial advances for improving indoor air quality. This paper provides a comprehensive analysis of the antimicrobial mechanisms, development of materials, and deployment strategies, as well as a performance evaluation of the antimicrobial implication for indoor air quality. Furthermore, the challenges and opportunities of future research directions are also highlighted. [ABSTRACT FROM AUTHOR]

Green and intelligent manufacturing has become the key direction of industrial production development. In-situ measuring and sintering simulation technologies play a key role in the modification of ceramic materials and the optimization of the sintering process. These two techniques can significantly alleviate the problems of wasted energy and resources in the ceramics production process, thus promoting the green development of the ceramics industry. Although both techniques have been widely used in the field of ceramic sintering, there is a lack of a comprehensive review of their applications. To better promote the application of these two technologies, this paper provides the first overview of the progress of the application of ceramic sintering in-situ measuring technology and systematically reviews the current research status of ceramic sintering simulation technology. Then it looks forward to the application prospect of these two technologies, synthesizes these two technologies, constructs the framework of digital twin ceramic sintering system for the first time, and analyzes the important role of these two technologies in the digital twin ceramic sintering system. [ABSTRACT FROM AUTHOR]

In this paper, the mechanical damage behavior is investigated based on the characteristic roughness on the surface and the orientation of superficial structures. The main goal is to explore the surface roughness on mechanically loaded copper conductors as a lifetime indicator. For this purpose, copper conductors are mechanically stressed in accordance with EN 50,396 and then examined metallographically and microscopically. The microstructure examination shows that the roughness is caused by material extrusion and cracks due to work hardening in the surface area. Using confocal microscopy, it is shown for the first time that significant formation of surface roughness takes place over the service life of copper conductors. The roughness increases monotonically, but not linearly with number of cycles, due to internal microstructural processes and can be divided into three sections. First inspections of the conductor surface over lifetime show a correlation between the intensity of structures orientated 45° to the loading direction and the roughness. This phenomenon, already known from microscopic slip lines, is thus also evident in macroscopic roughness formation and is well founded by the research theory on material extrusion along dislocation lines. In summary, a lifetime determination is possible based on its developing roughness which enables the utilization as a sensor element. [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]

Bacterial cellulose (BC) is a pure biopolymer with abundant sources. BC has been used in wound dressings, artificial blood vessels, bone tissue engineering, and other applications because of its microporosity, superior water retention, thermal stability, and biocompatibility. The tensile strength of pure BC in wet state is weak, and the water holding capacity is above 90%, which limits its application. However, the mechanical properties of dehydrated BC are excellent at the expense of toughness, which is not enough to meet the demand of high additional-value materials, such as high strength flexible electronic device substrate, wearable electronic devices, vibration film for microphone and earphone, and others. Therefore, it is of great importance to systematically investigate the strategies to improve the mechanical properties of BC. Herein, this paper demonstrates the intrinsic factors affecting the mechanical properties of BC, along with the strategies to enhance the mechanical properties. Compared with the well-known adhesion reinforcement and chemical modification, six strategies to enhance the mechanical properties were discussed thoroughly in this paper. In addition, layer-by-layer self-assembly and orderly arrangement of fibrils are proposed in this paper to improve the mechanical properties of BC, which have not been described in detail in previous literature. [ABSTRACT FROM AUTHOR]

In a typical electrochromic process of tungsten trioxide (WO3), the mismatch in conductive properties between electrons and ions tends to decrease the coloration efficiency and the cyclic stability. Recent studies lay emphasize on improving ionic kinetics, but few reports have focused on the control of electron injection to achieve charge balance for the electrochromic process. Therefore, a novel strategy is proposed in this paper, which is to insert polyvinylidene fluoride (PVDF) as an interlayer between WO3 and FTO substrate for interface modification. Through the modulation of its structure and morphology, WO3 grown on PVDF is found to have better capacity of ionic diffusion. Furthermore, electrical measurements indicate that the electron current can be effectively controlled by adjusting the PVDF film thickness. The adoption of PVDF interlayer can jointly achieve the improvement in ion dynamics and the control of electron injection. Compared with the pure WO3 film, the WO3/PVDF hybrid structure boosts the coloration efficiency from 34.9 to 75.7 cm2C−1, and the degradation in optical modulation after 1000 cycles is only 2.3%. This strategy based on a facile interface modification enriches the methodology of promoting electrochromic performance of WO3. [ABSTRACT FROM AUTHOR]

In the production of boxes, it is customary to align the flutes vertically, corresponding to a 0° flute angle. This configuration is widely believed to yield optimal compressive strength, despite existing evidence from corrugated flute boards and boxes that challenge this assumption. The present study investigates the hypothesis that non-vertical flute angles do not significantly compromise box compression strength and may potentially offer enhancements in other performance characteristics. Regular slotted container boxes (385 × 238 × 300 mm) constructed from single wall C-flute board were used in this study. Ten flute angles were selected for box level testing: 0°, 5°, 7.5°, 10°, 12.5°, 15°, 20°, 30°, 45° and 60°. Samples of converted board were subjected to edge crush testing (ECT) following TAPPI T-811 and four-point-bending following TAPPI T-820. Box crush testing (BCT) followed NZS 1301.800 2006 (New Zealand Standard). Component testing results were consistent with previous studies. Outcomes showed a general linear reduction in ECT with increasing flute angle, and nonlinear relationships between flute angle and bending force and stiffness. At the box level, peak load did not decline significantly between 0° and 45°, however 60° flute angles had significantly lower peak loads (α = 0.05). At certain angles, notably 10° and 30°, less variation in peak load was observed. BCT force and stiffness of the box significantly improved in terms of median and variation at 10° and 30°. Therefore, a flute angle of less than 45° does not significantly reduce compression strength. [ABSTRACT FROM AUTHOR]

The mechanical properties of the materials are determined by the size and morphology of fine microscopic features. Quantitative microstructural analysis is a key factor to establish the correlation between the mechanical properties and the thermomechanical treatment under which material condition has been achieved. As such, microstructural analysis is a very important and complex task within the manufacturing sector. Published standards are used for metallographic analysis but typically involve extensive manual interpretation of grain boundaries, resulting in measurements that are slow to produce, difficult to repeat and highly subjective. Computer vision and the evolution of artificial intelligence in the past decade can offer solutions to such problems. Deep learning and digital image processing techniques allow digital microstructural analysis to be automated using a fast and repeatable method. This paper proposes a novel boundary class semantic segmentation approach (BCSS) to identify each phase of the microstructure and additionally estimate the location of the grain boundaries. The BCSS is then combined with more traditional segmentation techniques based on the Watershed Transform to improve the identification and measurement of each feature within the microstructure using a new, hybrid automated digital microstructure analysis approach. The new method is validated on a published dataset of two-phase titanium alloy microstructure pictures captured using a scanning electron microscope. Measurements match the level of accuracy of accepted manual standards, and the method is demonstrated to be more reliable than other automated approaches. The influence of the subjective nature of manual labelling, required to train the proposed network, is also evaluated. [ABSTRACT FROM AUTHOR]

This review article focuses on the role of nanotechnology (NT) in the development of advanced organic and inorganic photodetectors and their potential applications in the coming decades. We initiate the article with an overview of NT and potential applications of Nanotechnology in the twenty-first century ranging from Semiconductor manufacturing to Medical Imaging to Renewable energy to Quantum computing to Opto-electronics. The second part of the article delved into specific details on the role of nanotechnology and nanomaterials in developing advanced Photodetectors (PDs) and specifically discussing the internal functioning of near-infrared (NIR) photodetectors. Subsequently we focused on the performance metrics of PDs and types of PDs namely Organic Photodetectors (OPD) and Inorganic Photodetectors (IPD). We continued our in-depth discussion on OPDs and IPDs elaborating their structural features, operation mechanisms, types, performance optimization and role of functional nanomaterials. The final part of this review focuses on key applications of photodetectors e.g., retinal implant, biomedical imaging, personalized health monitoring, telecommunication, and military applications etc. Finally, we concluded the review paper discussing future opportunities and challenges regarding applications of NIR photodetectors in the twenty-first century. [ABSTRACT FROM AUTHOR]

The resulting microstructure after the sintering process determines many materials properties of interest. In order to understand the microstructural evolution, simulations are often employed. One such simulation method is the phase-field method, which has garnered much interest in recent decades. However, the method lacks a complete model for sintering, as previous works could show unphysical effects and the inability to reach representative volume elements. Thus the present paper aims to close this gap by employing molecular dynamics and determining rules of motion which can be translated to a phase-field model. The key realization is that vacancy absorption induced motion of grains travels through a grain structure without resistance. Hence the total displacement field of a green body is simply the superposition of all grains reacting in isolation to local vacancy absorption events. The resulting phase-field model is shown to be representative starting from particle counts between 97 and 262 and contains the qualitative correct dependence of sintering rate on particle size. [ABSTRACT FROM AUTHOR]

Organic phase change materials (PCMs) have received increasing attention for their applications in the fields such as solar energy storage and thermal management. Low thermal conductivity is a major key issue that hinders their practical applications. It has become a research hotspot to investigate the three-dimensional (3D) network method to improve the thermal performance of organic PCMs compared with the traditional blending method. Thermally conductive fillers form a 3D network in the resin matrix, which can enrich the thermal conductive pathway and effectively enhance the thermal conductivity. This paper mainly summarizes the research progress, preparation methods and influencing factors of composite PCMs, focusing on the methods of constructing 3D thermal conductivity network. It is hoped to provide reference or suggestion for the preparation of novel PCMs. [ABSTRACT FROM AUTHOR]

Intermetallic compounds, due to their well-defined stoichiometry, arrangement of atoms and controlled crystal structure, are a promising alternative to expensive noble metal catalysts. In this paper, the catalytic properties of Al-13.5 at.% Cr and Al-13.5 at.% V alloys, corresponding to the quasicrystalline approximants Al45Cr7 and Al45V7, were investigated for the first time. The alloys in the form of fragmented brittle ribbons were produced by the melt-spinning. The microstructure of the ribbons, both in the as-spun state and after heat treatment (100 h at 600 °C), was characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. In the as-spun state, the ribbons showed a multiphase microstructure. In addition to the Al45Cr7 phase in the Al-Cr alloy and the Al3V phase in the Al-V alloy, they also contained α(Al) solid solution and icosahedral quasicrystalline phases. After heat treatment, the alloys became almost single phase, consisting mainly of stable monoclinic phases: Al45Cr7 or Al45V7. The catalytic performance of the phenylacetylene hydrogenation reaction was tested on as-spun and heat-treated alloys that had previously been pulverized and sieved to select a powder fraction of less than 32 µm. All the tested materials show high substrate conversion, above 80% after 1 h reaction, along with high activity rate. The homogenized powders demonstrated a slightly better properties in relation to as-spun materials. These results confirm the potential of intermetallic catalysts, including the tested alloys, in hydrogenation reactions and verify the possibility of using the metallurgical method to obtain catalytically active materials. [ABSTRACT FROM AUTHOR]

In this paper, the electrical response of a carbon black polylactic acid 3D printed polymer is characterised in detail by a combination of advanced experimental techniques at different scale lengths. The electrical properties as a function of the temperature become repeatable after the second heating cycle, exhibiting different trends as a function of the printing parameters. Joule heating and oven-heating techniques have been compared, showing the advantages of the Joule heating method to maintain electrical conductivity due to the lower thermal inertia. Small-Angle X-Ray Scattering has been employed to discern the underlying physics, showing the crucial role of crystallinity, filler dispersion and carbon black aggregates to form an effective segregated conductive network. This investigation provides guidelines to produce 3D-printed devices with a reliable electrical response and the governing equations to operate them with sufficient accuracy for engineering applications. [ABSTRACT FROM AUTHOR]

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]

Inconel 625 flux-cored wire is widely used in the repair of solar energy storage pipelines because of its excellent corrosion resistance. In the application environment of molten salt pipeline containing high-temperature chloride, the surface of the repaired pipeline is easy to deposit salt film, which leads to high-temperature hot corrosion. In this paper, in order to study the hot corrosion mechanism of Inconel 625 cladding metal. Inconel 625 cladding metal was prepared by MAG welding. The corrosion behavior of Inconel 625 cladding metal under isothermal (800 °C) and thermal cycle (600–800 °C) conditions in KCl-MgCl2 (60–40 mol %) molten salt environment was investigated. The results showed that the corrosion rate of Inconel 625 cladding metal was 12.39 μm/year under 72-h isothermal conditions, and the corrosion products mainly included MgO and NiCr2O4. Under the condition of 3 thermal cycles, the corrosion rate of the sample was 11.21 μm/year, and the corrosion products mainly included MgO, NiCr2O4 and Cr2O3. This was because the Cr2O3 protective shell dissolved and fell off under isothermal conditions. Besides, the hot corrosion path penetrated along the random HAGBs. The larger number of HAGBs increased the diffusion path of Cr element, which led to increased corrosion under isothermal conditions. Under the condition of thermal cycle, there was an intermittent cooling effect, and the corrosion time was less at the highest temperature, which improved the stability of the Cr2O3 protective shell. At the same time, it reduced the number of HAGBs and reduced the penetration path of hot corrosion. The diffusion coefficient of Cr element was reduced by 55.6%, which reduced the corrosion rate. [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]

Graphene oxide-based fire alarm sensors have received the most extensive research. Various organic and inorganic flame retardants and reducing agents as well as conductive fillers have been used to improve the temperature sensitivity of graphene oxide-based fire sensors. However, the effect of graphene oxide (GO) itself has sometimes been neglected by many researchers, since the synthesis of different structures of GO has received little attention. Here, we prepared two sensors, including the fire alarm based on GO synthesized at low temperatures (LGO) and the fire alarm based on GO synthesized by the conventional Hummers method (HGO). Compared with the HGO-based fire alarms, the improved temperature sensitivity of the LGO-based fire alarms is mainly due to the lower thermal decomposition temperature of the oxygen-containing functional groups in the LGO sheets. Interestingly, the LGO-based fire alarm has a response time of ~ 148 s at 150 °C, while the HGO does not respond. This finding will provide new ideas for the design of advanced GO-based fire alarm sensors. The low-temperature synthesized graphene oxide/nano-graphite (LGO/G) composite film can be applied as desirable smart fire early warning sensor material. [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]

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]

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]

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 past two decades, humidity actuators have received extensive attention from researchers due to their merits of simple stimulation, no pollution, programmable actuation behaviour, and simple structure. However, in order to perform more complex and difficult tasks, it is indispensable to enhance the response speed of the humidity actuators. Therefore, we mainly discuss the influence of materials and structure on the response speed of the actuators in this paper. In this review, the materials of the actuators include inorganic materials, polymers, biomaterials, hybrid materials, and structural materials. According to the structures, the actuators can be divided into monolayer film and multilayer film types. In addition, the applications of humidity-driven actuators in humidity detection, soft robot, self-power and medical equipment are introduced, providing a reference for the large-scale application of humidity actuators. Finally, this review also considers the practical challenges faced by humidity-driven actuators, summarizes how these challenges affect the potential applications of the actuators, and prospects for the future development trend of the actuators. [ABSTRACT FROM AUTHOR]