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The present paper investigates the effect of carbon nanofibers (CNFs) on the microstructure and mechanical properties of Carbon fiber reinforced carbon and silicon carbide binary matrix (C/C–SiC) composite prepared by using the reactive melt infiltration technique. The CNFs used in this paper were generated through in-situ reaction in the pores of C/C preforms using the chemical vapor deposition. Results indicate introducing additional carbon sources in the form of CNFs in the C/C preform can remarkably improve the permeability of molten Si, resulting in higher density and more uniform microstructure of the RMI-deriver C/C–SiC composites. Consequently, the in-situ formation of CNFs reduces the residual Si content by 64.71% and increases the mechanical strength and modulus at room temperature by [22.31% and 17.89%] and after heat treatment at 1500 °C by [35.6% and 47.48%] with respect to no-CNF containing composites due to a lower amount of residual Si content and additional reinforcement effect of the unreacted CNFs. [ABSTRACT FROM AUTHOR]

The 2319-Al alloy is widely used in aviation industry. The crack-free 2319 alloy thin-walled sample was fabricated utilizing the laser-CMT composite additive manufacturing technique, achieving a material utilization rate of 96.43%. The impact of deposition parameters and deposition height on the microstructure and mechanical properties was studied. The microhardness of the additive manufacturing samples exhibited a gradual decrease from construction direction, with values reaching 90 HV, 78 HV, and 72 HV, respectively. The tensile property also exhibited a gradual decrease from the bottom to the top; the highest tensile strength was 296 MPa. The grain size along the construction direction of the deposited sample gradually increased, exhibiting respective sizes of 34.7 um, 36.6 um, and 45.7 um. With the increase in the height of the second phase, the segregation at the grain boundary is intensified, and as the size inside the grain increases, the corresponding density decreases. The good laser-CMT composite additively manufactured 2319 aluminum alloy samples could be obtained under the optimized deposition parameters. [ABSTRACT FROM AUTHOR]

Based on advanced first-principle calculations driven by density functional theory, our study used fusion casting techniques to incorporate minute quantities of In into the conventional Pb-56Bi eutectic alloy. Detailed examination identified the critical parameters of the prepared materials, including melting point, phase formation and microstructure. The initial Pb56Bi alloy had a melting point of 125°C, while the inclusion of In yielded Pb-56Bi-XIn (X represents the percentage of In element) and decreased the melting temperature to 85.7°C–119.7°C. [ABSTRACT FROM AUTHOR]

A set of novel (AlTiCrVTa)N x coatings are synthesized by DC magnetron sputtering to methodically investigate the effect of nitrogen content on the microstructure, mechanical and tribological properties and oxidation behavior of the coatings for the first time. As the nitrogen content increases, the coating structure transitions from amorphous to a simple fcc structure, accompanied by a change of preferred orientation from (200) to (111) and an enhancement in crystallinity. The coating morphology changes from featureless glassy to columnar crystals. The highest nanohardness of 38.1 GPa and the best wear rate of 4.9 × 10−7 mm3/Nm are achieved at 43.3 at.% nitrogen content. The friction coefficient exhibits a downward trend with rising nitrogen content, reaching the lowest value of 0.47 at 49.8 at.% nitrogen content. The oxidation tests reveal that the oxidation resistance deteriorates with increasing nitrogen content, caused by the looser structure and large-sized grain boundaries. [ABSTRACT FROM AUTHOR]

High entropy carbide ceramics have attracted much attention because of their high hardness and chemical inertness, but the relatively low fracture toughness limits their actual industrial applications. In this work, high entropy (MoTaTiVW)C 5 ceramics reinforced with silicon carbide whisker (SiC w) were fabricated with spark plasma sintering. The effects of SiC w contents and sintering temperatures on the microstructure and mechanical properties of (MoTaTiVW)C 5 have been studied. The outcomes show that by optimizing the sintering temperature, a dense microstructure with intact SiC w were obtained which could fully utilize the toughening effect of the SiC w and thus exhibits an enhanced mechanical property. Additionally, the presence of solid solution oxide particles in the sintered bulks is also beneficial for the improved toughness. The sample with 5 wt% SiC w sintered at 1700 °C exhibited higher hardness of 19.63 GPa and fracture toughness of 6.26 MPa m1/2, which is attributed to the combined toughening effects (crack deflection, crack bridging, and whisker/particle extraction) of SiC w and oxide particles. The findings contribute to the development of advanced ceramic materials with improved mechanical properties for various applications. [ABSTRACT FROM AUTHOR]

In this paper, the workability, mechanical, ion leaching, and drying shrinkage properties of alkali-activated concrete with recycled coarse and fine aggregates were studied, and the pore structure and micro-morphology of different alkali-activated recycled aggregate concretes (AARACs) were characterized by using the mercury intrusion method and scanning electron microscopy, respectively. The experimental results showed that with the increase in the replacement rate of the recycled fine aggregate (RFA), the flowability showed a decreasing trend. Adding a certain amount of RFA improves the mechanical properties of the AARAC. The compressive strength at a curing age of 28 days was 65.3 MPa with 70 wt% RFA replacement. When the replacement rate of the RFA was 100 wt%, the maximum splitting tensile strength (4.5 MPa) was obtained at a curing age of 7 days. However, the addition of the RFA had little effect on the flexural strength of the AARAC. As an extension of the curing age, the splitting tensile strength, flexural strength, tension-to-compression ratio, and flexure-to-compression ratio all showed an increasing trend at first and then a decreasing trend. At a curing age of 7 days, the tension-to-compression ratio and flexure-to-compression ratio were both high (except for those of R100), indicating that the ductility and toughness of the specimen were improved. The addition of the RFA increased the drying shrinkage of the AARAC. At a curing age of 120 days, compared to the specimen without the RFA, the drying shrinkage rate of the specimen with the addition of 70 wt% RFA increased by 34.15%. As the curing age increased, the microstructure of the reaction products became denser, but the proportion of large-diameter pores increased. This study evaluated the application of RFA in AARAC. The experimental results showed that the RFA-based AARAC had acceptable mechanical and durability properties. [ABSTRACT FROM AUTHOR]

AlN ceramics exhibit good physical and chemical properties and are ideal materials for the dielectric layer of electrostatic chucks. However, they cannot generate a strong J−R-type electrostatic adsorption force because of their high resistivity. Therefore, adding other substances is necessary to regulate the electrical properties and enable their application. In this study, AlN ceramics were prepared using hot-pressed sintering with 0.2 wt% CaO as an additive at a sintering temperature range of 1700–1900 °C. The effects of CaO doping on the phase composition, microstructure, electrical properties, and thermal conductivity of the AlN ceramics were systematically investigated. The addition of CaO not only enhanced the sintering process of the AlN ceramics, but also significantly reduced the electrical resistivity and increased the thermal conductivity. The relative density of CaO-doped AlN ceramics reached 98.88 % at 1700 °C, with a thermal conductivity of 81.51 W m−1•K−1. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and AC impedance spectroscopy were used to analyse the impurities and defects in the AlN ceramics. The lattice parameters and fitting grain resistance indicated that the CaO-doped AlN presented a higher lattice oxygen concentration, increasing the concentration of Al vacancies and electrons. Moreover, the level of dissolved oxygen could be controlled by altering the sintering temperature, resulting in AlN ceramics with electrical resistivity ranging from 8.1 × 106 to 1.7 × 1012 Ω cm. Further research was conducted to investigate the effect of the electrical resistivity of AlN ceramics on the J−R-type electrostatic adsorption force, and it was found that AlN ceramics with a specific resistivity of 109 Ω cm exhibited the highest electrostatic adsorption of 351.7 g/cm2. [ABSTRACT FROM AUTHOR]

This research focuses on the evolution of mechanical behavior of bimodal mixtures undergoing compaction and diametrical compression. The clusters were built and discrete element method (DEM) was used to investigate the densification process and micromechanics of bimodal mixtures. Additionally, a more comprehensive investigate of the respective breakage of the bimodal mixtures has been carried out. On this basis, qualitative and quantitative analysis of the compressive force, force chain, contact bonds and density field evolution characteristics of the clusters are investigated during the compression process. The entire loading process of the clusters is divided into three stages: rearrangement, breakage and elastic–plastic deformation. Additionally, there are differences in the evolution of micromechanics behavior of different particles in the bimodal mixture, with pregelatinized starch breakage and deformation occurring before microcrystalline cellulose. With the tablet deformation, the fragmentation process of the tablet started at the point of contact and extended toward the center, and the curvature of the force chain increased. This approach may potentially hold a valuable new information relevant to important transformation forms batch manufacturing to advanced manufacturing for the oral solid dosage form. [ABSTRACT FROM AUTHOR]

The aim of this work was to investigate the impacts of MgO on the crystalline behaviors, microstructure, and properties of CaO–B 2 O 3 –SiO 2 (CBS) glass-ceramics. In the study, the CBS samples with various MgO contents were developed via the melting and quenching route. Subsequently, a CBS casting tape and a multi-layered LTCC microcircuit module were created by using the tape casting method. Results indicated that MgO could break the glass network and promote the formation of liquid phase during the sintering process. A suitable amount of MgO additive promoted densification during firing process and improved the properties of the CBS materials. The CBS sample with 1.5 wt% MgO fired at 875 °C exhibited outstanding properties, including a dielectric constant (ε r) of 6.5 (at 10 GHz), a dielectric loss (tan δ) of 8 × 10−4, a flexural strength of 167 MPa, a coefficient of thermal expansion (CTE) of 6.8 ppm/°C, and a thermal conductivity (λ) of 2.2 W/mK. In addition, this LTCC material demonstrated good co-firing compatibility with silver electrodes and superior temperature stability, showing its great potential for microelectronic applications. [ABSTRACT FROM AUTHOR]

Summary: Rice glutelin is poorly soluble which restricts its potential food application. Succinylation is a chemical modification that improves the solubility of proteins by derivatising the ɛ‐amino group of lysine residues. In this study, rice glutelin was modified by succinic anhydride at different succinic anhydride concentrations (10%, 20%, 30%, 40%, and 50%). The succinylated rice glutelin samples showed enhanced solubility, reduced particle size, and increased absolute zeta potential values. The emulsifying and foaming properties of succinylated rice glutelin were also significantly improved. Moreover, SEM revealed that the surface of succinylated rice glutelin had small pits and protrusions. These results suggest that succinylation can effectively improve the functional properties of rice glutelin, which will facilitate its application in the food industry. [ABSTRACT FROM AUTHOR]

Compacted graphite iron (CGI) is an engineering material with the potential to fill the application gap between flake- and spheroidal-graphite irons thanks to its unique microstructure and competitive price. Despite its wide use and considerable past research, its complex microstructure often leads researchers to focus on models based on representative volume elements with multiple particles, frequently overlooking the impact of individual particle shapes and interactions between the neighbouring particles on crack initiation and propagation. This study focuses on the effects of graphite morphology and spacing between inclusions on the mechanical and fracture behaviours of CGI at the microscale. In this work, 2D cohesive-zone-element-based models with different graphite morphologies and spacings were developed to investigate the mechanical behaviour as well as crack initiation and propagation. ImageJ and scanning electron microscopy were used to characterise and analyse the microstructure of CGI. In simulations, both graphite particles and metallic matrix were assumed isotropic and ductile. Cohesive zone elements (CZEs) were employed in the whole domain studied. It was found that graphite morphology had a negligible effect on interface debonding but nodular inclusions can notably enhance the stiffness of the material and effectively impede the propagation of cracks within the matrix. Besides, a small distance between graphite particles accelerates the crack growth. These results can be used to design and manufacture better metal-matrix composites. [ABSTRACT FROM AUTHOR]

The (W,Mo,Ta,Nb,Ti)(C,N) high-entropy carbonitride powders were synthesized by the carbothermal reduction nitridation method, utilizing equimolar proportions of either graphite or carbon black. The subsequent utilization of these pre-synthesized powders yielded carbonitride ceramics after spark plasma sintering. The choice of carbon source played an important role in the microstructure, phase compositions and mechanical properties. By employing carbon black with its fine particle size and high reactivity, the synthesized powder maintained finer size, narrow powder size distribution (350 ± 12 nm) and have less free-carbon (∼0.032 wt%), which contributed to the high hardness (26.8 ± 1.4 GPa) of the sintered ceramic. Conversely, utilizing graphite with its larger particle size and lower reactivity would increase the fraction of free-carbon, leading to the deterioration of the ceramic's performance. [ABSTRACT FROM AUTHOR]

Two BaZr 0.1 Ce 0.7 Y 0.2 O 3-δ (BZCY) powders prepared by solid-state reaction (BZCY(sr)) and sol-gel (BZCY(sg)) methods and three NiO powders (two commercial NiO with large (NiO(L)) and small (NiO(S)) particles and one prepared by solution-infiltration method (NiO(I)) are used to study the effect of the particle sizes of BZCY powder and NiO sintering aid on the sinterability and conductivity of sintered BZCY electrolytes for protonic ceramic fuel cells (PCFCs). The BZCY and NiO powders are examined by X-ray diffraction and scanning electron microscopy (SEM). The microstructures of the six BZCY-NiO mixtures sintered at 1500 °C in air for 6 h, named as sr-L, sr-S, sr-I, sg-L, sg-S, and sg-I, are characterized by SEM to compare their pore morphology and grain size, and their conductivities from 550 to 800 °C in a 5 vol% H 2 –N 2 atmosphere are measured using the four-probe and impedance spectroscopy methods, respectively. The results show that sr-L and sg-L are not fully dense with large pores, most of them are at the grain boundaries; sr-S and sg-S have a much denser microstructure; sr-I and sg-I have the highest density with fine pores. The average grain size, the conductivity, and the grain-boundary resistance follow the orders of sr-L (8.16 μm) ≈ sg-L (8.53 μm) < sr-S (10.59 μm) ≈ sg-I (10.65 μm) < sg-S (14.07 μm) < sg-I (26.08 μm), sr-L < sg-L < sr-S < sg-S ≈ sr-I < sg-I, and sr-L > sg-L > sr-S > sg-S ≈ sr-I > sg-I, respectively. The above results indicate that both the density and grain size affect the conductivity critically, and sg-I with the small-particle BZCY and fine and uniformly distributed NiO sintering aid has the highest sintered density and the biggest grains (fewest grain boundaries) and in turn the highest conductivity (0.039 S cm−1 at 800 °C). A cell with the sg-I electrolyte demonstrates electrochemical performance 1.8 times higher than that with the sr-L electrolyte. • Finer BZCY powder with smaller-particle NiO powder as a sintering aid leads to a higher sintering activity. • Sg-I has the biggest grains and highest conductivity. • A cell with the sg-I electrolyte demonstrates electrochemical performance 1.8 times higher than that with the sr-L. [ABSTRACT FROM AUTHOR]

The development of materials has coincided with the development of human civilization. In recent years, high-entropy alloys (HEAs) have been extensively applied to structural and functional materials owing to their unique physical and chemical properties. Therefore, HEAs have emerged as a promising materials. This review summarizes recent research progress on HEAs for hydrogen storage. First, the history and basic concepts of HEAs are systematically introduced. Furthermore, recent developments in the field of HEA-based hydrogen storage are reviewed and discussed. The preparation process, design methods, microstructures, and hydrogen-storage performance of HEAs are systematically compared and summarized. Other hydrogen-related applications are also presented. Finally, the shortcomings of the HEAs currently used in hydrogen-storage applications are highlighted, and future development directions are outlined. • The research status of high-entropy hydrogen storage alloys is reviewed. • The advantages of high-entropy alloys in hydrogen storage performance are shown. • The shortcomings of high-entropy hydrogen storage alloys are pointed out. • The development direction in the future is outlined. [ABSTRACT FROM AUTHOR]

In the present work, the microstructures and mechanical properties of Cu-foam-(graphene, LiAlSiO 4 and graphene/LiAlSiO 4) and a CoCrNiFeCuSn high-entropy alloy as a composite interlayer for brazing Zr and silicon carbide (SiC) ceramics are explored. Further, the effects of graphene, LiAlSiO 4 , and graphene/LiAlSiO 4 on the mechanical properties and microstructure of the SiC/Zr joint are investigated. The results of the data analysis reveal a good connection between SiC and Zr at 1040 °C for 20 min using the different composite interlayers, Cu-foam-graphene, Cu-foam-LiAlSiO 4 , or Cu-foam-graphene-LiAlSiO 4 , with shear strengths of 122, 147, and 235 MPa, respectively. Particularly, the Cu-foam-graphene-LiAlSiO 4 brazed joint demonstrates the highest shear strength. Furthermore, the dispersion of LiAlSiO 4 in the joint reduces the coefficients of thermal expansion of difference between the brazing materials and ceramics, as well as the residual stress in the joint. Moreover, the synergistic effect of the solid-solution phase, Zr(s, s), with excellent plastic deformation, and enhanced Zr(Cr, Fe) 2 phase further improves the strength and plasticity of the joint. [ABSTRACT FROM AUTHOR]

In recent years, high entropy alloy (HEA) matrix composites have undergone rapid development. In this work, the effects of different WC contents (10 wt.%, 20 wt.%, and 30 wt.%) on the microstructure, mechanical properties, and wear resistance of FeCoCrNi HEA matrix composites prepared by spark plasma sintering (SPS) were studied. The results show that the WC–HEA composites are mainly composed of an FCC matrix phase (Ni, Fe) and carbide phases (Cr7C3, Co3W3C, WC, etc.). The hardness of the 30 WC–HEA composites was the highest at 459.2 HV, which is 71.2% higher than the 268.3 HV of the pure matrix material. Similarly, the compressive yield strength of the 30 WC–HEA composite was the largest, reaching 1315.1 MPa, which is 112.1% higher than that of the pure matrix material. However, the compression deformation rate of the 30 WC–HEA composite significantly decreased to 16.6%. Under the same dry friction conditions, the addition of an appropriate amount of WC particles can reduce the friction coefficient of the HEA matrix. The wear volume of the composites decreased rapidly with the increase of WC content. The wear volume of 30 WC–HEA was the lowest, only 3.17% of that of the pure matrix material. [ABSTRACT FROM AUTHOR]

Zn coatings on Mg alloy substrate were prepared by in-situ micro-forging-assisted cold spraying with different stainless steel shot additions. Phase, microstructure, mechanical properties and corrosion resistance of Zn coatings were investigated. The results show that the shot addition enhanced the ZnO formation and increased the full width at half maximum of the Zn phase in the Zn coatings. Plastic deformation of Zn particles was enhanced with the coating densities. Microhardness of Zn coatings was increased due to work hardening, grain refinement and densification by the hammering effect of shots. Bond strength was increased and fracture surfaces showed both metallurgical bonding and mechanical interparticle interlocking in Zn coatings. Zn coatings effectively improved the corrosion resistance of the Mg alloy substrate, and the shot addition made a small contribution to the corrosion resistance. The corrosion behavior of Zn coatings was discussed in terms of corrosion products and microstructures after immersion. [ABSTRACT FROM AUTHOR]

In this study, the functional properties of a mixture consisting of Tremella aurantialba powder (TAP) and wheat flour were investigated. Further, the effects of adding 0%, 1%, 3%, 5%, and 10% TAP on the physical properties of bread, as well as its glucose release, microstructure, and rheology during in vitro simulated digestion were studied. The water‐holding, oil‐holding, and swelling capacities of wheat flour were significantly enhanced (p < 0.05) with the increase of TAP. The addition of TAP increased the hardness, chewiness, gumminess, and moisture content and darkened the color of the bread. Sensory evaluation showed that adding the 3% of TAP could produce bread that satisfies the requirements of consumers. Furthermore, adding TAP could inhibit the release of glucose from the digesta into the dialysis solution, especially the addition of 10% TAP reduced the release of bread glucose by 23.81%. This phenomenon might be related to the increased viscosity of the digesta and the smooth physical barrier on the surface of starch granules during simulated in vitro digestion of bread. Therefore, as a natural food, T. aurantialba has great potential in improving the functional properties of bread and the application of starch matrix products. [ABSTRACT FROM AUTHOR]

Bulk metallic glasses (BMGs) display excellent strength, high hardness, exceptional wear resistance and corrosion resistance owing to its amorphous structure. However, the manufacturing of large-sized and complex shaped BMG parts faces significant difficulties, which seriously hinders their applications. Laser powder bed fusion (LPBF) is a typical additive manufacturing (AM) technique with a cooling rate of up to 108 K/s, which not only allows for the formation of amorphous structures but also solves the forming problem of complex-shaped BMG parts. In recent years, a large amount of work has been carried out on the LPBF processing of BMGs. This review mainly summarizes the latest progress in the field of LPBF additively manufactured BMGs focusing on their mechanical properties. We first briefly review the BMG alloy systems that have been additively manufactured using LPBF, then the mechanical properties of LPBF-fabricated BMGs including the micro- and nano-hardness, micropillar compressive performance, and macro-compressive and tensile performance are clarified. Next, the relationship between the mechanical properties and microstructure of BMGs produced via LPBF are analyzed. Finally, the measures for improving the mechanical properties of LPBF-fabricated BMGs are discussed. This review can provide readers with an essential comprehension of the structural and mechanical properties of LPBF-manufactured BMGs. [ABSTRACT FROM AUTHOR]

AISI 1045 steel has the characteristics of high strain rate, large strain, and sharp rise in temperature during high-speed deformation process, resulting in a concentrated deformation band and fine structure. In this work, the microstructure of submicron-sized grains in AISI 1045 steel material formed under 106 s–1 during a high speed cutting process was examined. To reveal the dynamic evolution mechanism of the AISI 1045 microstructure, the continuous dynamic recrystallization theory was introduced. The results show a high dislocation density which favor the formation of small angle grain boundaries during the high speed cutting process. Kinetics calculations that use continuous dynamic recrystallization mechanisms prove that the recrystallization size is constant when the strain rate increases from 10³ s–1 to 106 s–1, and the transition time is reduced from 6×10–5 s to 4×10–8 s. The recrystallization grains were gradually formed during the deformation of the material, not generated after the deformation. [ABSTRACT FROM AUTHOR]

Vanadium-based hydrogen storage alloys have been widely investigated; however, alloys in the cast state are typically coarse-grained. In this study, an as-cast V 45 Fe 15 Ti 20 Cr 20 medium-entropy alloy was prepared by arc melting, and microstructural analysis revealed that the alloy was composed of nanocrystals. The initial pretreatment temperature of the alloy was approximately 100 K lower than that of the as-cast coarse-grained alloy. At room temperature, the time required for the alloy to reach 90% saturation was only 140 s, indicating excellent hydrogen absorption kinetics. The alloy is fully activated after two hydrogen absorption/desorption cycles. The phase transformation of the alloy in the early hydrogenation stage was investigated using X-ray diffraction, and the results showed that the BCC phase was completely transformed into the BCT phase when hydrogen uptake was performed for 6 s. Furthermore, the apparent activation energy of dehydrogenation in the present alloy calculated using the Kissinger method was 69.8 ± 0.8 kJ/mol. The pressure-composition-isotherms tests showed that the hydrogen absorption capacity of the alloy at 295 K was 2.12 wt%. The hydrogenation/dehydrogenation enthalpy change of the alloy was calculated by the Van't Hoff equation, which was 30.90 ± 1.47 and 33.95 ± 0.41 kJ/mol, respectively. The present work demonstrates that nanostructured vanadium-based hydrogen storage alloys can be fabricated using traditional casting techniques. Our study also enriches the understanding of the microstructures of medium-entropy alloys, which may provide positive guidance for the design of novel vanadium-based hydrogen storage alloys. • An as-cast V-based medium entropy alloy has a nano-scale microstructure. • Nanostructured alloys have very good kinetic properties at room temperature. • The phase transformations during absorption were studied. [ABSTRACT FROM AUTHOR]

Aluminum alloy adhesive bonding joint widely appears in many industrial products. Improving the mechanical performances of aluminum alloy bonding joints has been attracting much effort. To acquire more excellent bonding strength, this paper focused on the effects of different surface treatments, including laser ablation and milling superposed by phosphoric acid anodizing (PAA). The treated surfaces were characterized by roughness and contact angle, and the effects of the geometric parameters of microstructures on wettability, failure mode, and shear strength were examined. The results indicate that those surfaces where the spacing is smaller than the diameter present a hydrophilic property and the corresponding specimens are mainly subject to cohesive failure, and vice versa. Additionally, laser ablation with a properly designed dimple pattern can greatly improve the bonding strength, and the maximum average shear strength of specimens with a thickness of 50 μm reaches 32.82 MPa, which is an increase of 28.15% compared with the original milling specimen. Moreover, fabricating groove or grid patterns on the surfaces and applying PAA treatment can also significantly enhance the bonding strength, reaching up to 36.28 MPa. [ABSTRACT FROM AUTHOR]

During the construction and operation of a geological repository, with the infiltration of groundwater, highly compacted bentonite blocks hydrate and swell freely to fill up technological voids and gradually turn to hydrate under a constant-volume condition. Additionally, these processes are inevitably influenced by the pore chemistry of the groundwater. Therefore, it is necessary to investigate the hydration process of compacted bentonite under the combined influences of chemistry and technological voids. In this study, hydration tests were conducted on compacted GMZ bentonite with artificial annular gaps with infiltration of deionized water, 1 M NaCl, and 1 M CaCl2 solutions, respectively. Variation of swelling pressure and hydraulic conductivity with time was measured during hydration. The distribution of dry density, water content, and microstructure feature in the specimens was determined. Results show that sealing of the technological voids resulted in a heterogeneous distribution of dry density and water content of the barrier formed. Compared to that of deionized water, infiltration of salt solutions weakened swelling capacity and increased the permeability, leading to more significant heterogeneity in dry density distribution. During hydration, the specimen could be divided into swelling and compression zones according to variations of dry density with time. The boundary between the swelling and compression zones moved with hydration time. Evolutions of microstructure features were also affected by solutions. For specimens infiltrated with NaCl, more macro-pores and meso-pores were observed, while for CaCl2 infiltration, more undetectable pores and less meso-pore pores could be detected. After the tests, all the specimens were still in non-homogeneous states. [ABSTRACT FROM AUTHOR]

Poor interfacial contacts of Li mental/solid‐state electrolytes (SSEs) cause high impedance and induce lithium dendrite growth, which hinders the practical viability of solid‐state batteries (SSBs). Optimizing the surface chemistry of SSEs has been widely adopted for improving the Li/SSE interfacial contact. Their surface's microstructure, another critical factor influencing the actual performance of SSBs, however, has seldom been paid attention to; and the corresponding mechanism remains unclear. Addressing this issue, the authors herein propose a "surface microstructure optimization" strategy that can significantly enhance the Li/SSE interfacial contact, and in the meantime, quantify the correlations between SSB's performance and SSE's surface roughness regarding the interfacial resistance, current focusing, critical current density (CCD), and lithium deposition. Based on these fundamental understandings, a low‐surface‐roughness SSE is developed, which shows extremely small interfacial impedance (1.7 Ω cm2) and ultra‐long stable cycling life (4500 h at 0.2 mA cm−2). This work not only comprehensively demonstrates the fundamental relationship between the surface microstructure of SSEs and their battery performance but also presents a new insight into the modulation of surface kinetics of ceramic SSEs toward achieving dendrite‐free SSBs. [ABSTRACT FROM AUTHOR]

This work is motivated by the fact that the microstructures of nickel-based alloy forged parts influenced by hot deformation have a great impact on the mechanical properties of their final parts. In this paper, a simplified 2D half-symmetry FE model embedded with the JMAK model is developed to predict the deformation characteristics and microstructure behaviors of an IN718 aeroengine drum in hot forging procedure and then verified by experiments. Moreover, based on two evaluation indexes, the distribution uniformities and general levels of effective strain, strain rate, temperature, dynamic recrystallization, and grain size within the forged IN718 alloy drum are analyzed quantitatively. The results suggest that unlike strain rate and grain size, the maximum values of effective strain, temperature, and dynamic recrystallization volume fraction are located at the internal wall of the forged drum, and their distribution uniformities become worse with the increment of forging strokes. Besides, the Xavg and davg show an opposite evolution trend as increasing forging strokes, which are mainly related to the increments of εavg and Tavg as well as the grain refinement of dynamic recrystallization. [ABSTRACT FROM AUTHOR]

Nanoscale recombination between carbon nanomaterials (CNs) and polymers has been proposed for a variety of industrial and scientific applications. Composite energetic materials consisting of CNs with novel laser ignition property and tunable combustion performance have attracted people's attention. Here, reported is the novel manufacturing process of uniform nitrocellulose (NC)/graphene oxide (GO) nanocomposite propellant and the micro‐structure, laser ignition and isovolumetric burning features of the propellants introduced by GO. The results of microstructure tests indicated that GO (0.25–2 wt%) was stripped and dispersed homogeneously and dense nanocomposite propellants were prepared successfully through water ultrasonic dispersion, twin‐screw mixture, as well as compression molding. The crystallization of NC was forbidden by doping GO, meanwhile, the thermal stability and thermal conductivity of the composite propellants increased slightly with the addition of GO. The results of laser ignition combustion experiments showed that GO was an efficient additive to shorten the ignition delay time from more than 2000–14 ms when 2 wt% of GO was doped, however, the combustion flame intensity was also weakened due to the addition of GO. The combustion tests in a closed bomb vessel were conducted, and the results showed that GO would not affect the stable combustion of NC at high combustion pressure, moreover, the burning rate and dynamic vivacity of the composite propellants decreased with the increase of GO content. [ABSTRACT FROM AUTHOR]

The interface characteristics and formation mechanism of explosive welded waveform structures still lack a detailed and in-depth research. Thus, a combination of advanced characterization and numerical simulation methods were performed in this study to investigate the phase constitution, texture distribution, 3D interface morphology and wave formation mechanism of Sn/Cu explosive welded interface. The microstructure analyses indicated that the typical waveform structures composed of fine crystal band and elongated grains zone were formed at the Sn/Cu joining interface. The dynamic recrystallized structures and local high strain at the waveform were attributed to severe rheological deformation and rapid solidification of liquid metals. In addition, the S, copper, brass and fiber deformation textures and the cube and gross recrystallization textures were found. The CT results indicated the 3D Sn/Cu joining interface morphology presents a regular convex waveform feature, which is related to periodic pulse load caused by explosive detonation. Furthermore, based on the simulation results, the 2D joining interface presents similar experimental waveform structure, and the 3D interface evolution characteristic was consistent with the shock wave propagation characteristics on the flying plate to some extent, which was in good agreement with the experimental results. [ABSTRACT FROM AUTHOR]

Ni-based alloys were prepared at different sintering temperatures in this study. The effects of sintering temperature on the volume fraction, morphology, and distribution of precipitates in Ni-based alloys, and its impact on mechanical properties were studied. The results show that the microstructure contains γ-Ni, Ni 3 Si, M 7 (B, C) 3 , M 23 (B, C) 6 , and a Si-rich multi element phase. The morphology of M 7 (B, C) 3 particles undergoes an evolution of small particles → mainly strip shape → mainly small block shape and nearly spherical shape, accompanying with the dissolution-reprecipitation process of M 7 (B, C) 3 particles caused by the diffusion of Cr element with the increasing of sintering temperature. Meanwhile, the M 23 (B, C) 6 particle is keeping aggregating and growing. The relative density, microhardness, and bending strength of Ni-based alloys also increase. Especially these properties are found to be increase quickly between 1025 °C and 1050 °C. The increase in microhardness and bending strength is attributed to the reduction in the number of residual sintering pores and the increase in the volume fraction and size of precipitates. In addition, the transition of fracture morphology from intergranular fracture mode to a combination of intergranular and partially transgranular fracture mode also contributes to the rise in bending strength. • γ-Ni, Ni 3 Si, M 7 (B,C) 3 , M 23 (B,C) 6 , and a Si-rich multi element phase. • Morphology of M 7 (B,C) 3 particles relates to dissolution-reprecipitation process. • Mechanical properties with residual sintering pores and boron carbide. [ABSTRACT FROM AUTHOR]

• The Fe-Cr-Ni based composite coating was prepared using laser cladding method. • The addition of rare earth elements makes the cladding layer more dense and more refined. • Increased tensile strength, increased yield strength and increased impact value. Laser cladding technology was used to prepare Fe314 coating with added CeO 2 and La 2 O 3 on the surface of EA4T steel. The microstructure and structure of the coating were analyzed using scanning electron microscopy, electron probe microanalyzer, and X-ray diffraction. The mechanical properties of the coating were tested using a microhardness tester, universal testing machine, and pendulum impact testing machine. The results show that the addition of rare earth elements makes the cladding layer more dense and more refined; at the same time, compared to the base material, the tensile strength of the repaired specimen increased by 12.9 %, the yield strength increased by 23.3 %, and the impact value increased by 43.6 %. [ABSTRACT FROM AUTHOR]

Ni–tungsten carbide (WC) composites were prepared using cast WC as hard particles. In this study, the thermal damage behaviour of cast WC particles and its effects on the microstructure and mechanical properties of Ni–WC composites were investigated. Results show that cast WC particles undergo edge dissolution and particle disintegration at 1600 °C and 1800 °C, respectively. The degree of thermal damage to cast WC particles increases from 30.55% to 48.84% when the melting temperature increases from 1600 °C to 1800 °C. In this process, the Ni-based melt gradually erodes the cast WC particles from the edge towards the centre. This leads to severe dissolution of the W 2 C phase, while the WC phase only dissolves partially. Notably, the degree of thermal damage to cast WC directly correlates with the W content in the melt. An increase in the W content enhances the volume fraction and nano-hardness of the M 23 (B, C) 6 compound, improving the wear resistance of the composites. • Elevated temperature rises thermal damage degree of cast WC particle. • Ni-based melt invades from particle edge towards its center during thermal damage process. • High nano-hardness and volume-fraction of block-like M 23 (B,C) 6 compound • Thermal damage behaviour improves wear resistance of composite. [ABSTRACT FROM AUTHOR]

The balance between strength and toughness is of great importance. In this paper, the microstructure and properties of laminated composites in X-Y direction were characterized and analyzed. The effect of the content of α-Al2O3w and MWCNTs on the laminated structure and properties was analyzed, and strengthening mechanisms and toughening mechanisms of the material were discussed. The laminated structure of traditional Cu matrix composites was designed by a combination of flake powder metallurgy and SPS sintering. Compared with spherical Cu, flake Cu can increase the interface contact between matrix and reinforcement phase, which is conducive to the formation of self-assembly of laminated structure in SPS sintering process. The strength and compressive elongation of 1.0 wt.% MWCNTs-1.0 wt.% α-Al2O3w/Cu hybrid laminated composites were the best, reaching 453.43 MPa, 50%, respectively. This is mainly due to the composites containing MWCNTs less than 1.0 wt.% had uniform microstructure and good interfacial bonding, and the loads were effectively transferred from Cu matrix to MWCNTs and α-Al2O3w. At the same time, the large grain size in the plane is favorable for dislocation movement, while the interlayer interface and nanocrystals hinder the combination of dislocation movement perpendicular to the plane to achieve a balance of strength and toughness. [ABSTRACT FROM AUTHOR]

As anode material for sodium ion batteries (SIBs), biomass-derived hard carbon has attracted a great deal of attention from researchers because of its renewable nature and low cost. However, its application is greatly limited due to its low initial Coulomb efficiency (ICE). In this work, we employed a simple two-step method to prepare three different structures of hard carbon materials from sisal fibers and explored the structural effects on the ICE. It was determined that the obtained carbon material, with hollow and tubular structure (TSFC), exhibits the best electrochemical performance, with a high ICE of 76.7%, possessing a large layer spacing, a moderate specific surface area, and a hierarchical porous structure. In order to better understand the sodium storage behavior in this special structural material, exhaustive testing was performed. Combining the experimental and theoretical results, an "adsorption-intercalation" model for the sodium storage mechanism of the TSFC is proposed. [ABSTRACT FROM AUTHOR]

TiB 2 composite ceramics containing different amounts of Ti and TiC were fabricated via spark plasma sintering (SPS), and effects of their addition contents on the microstructure and mechanical properties were discussed. The newly formed phases of TiB with a cubic lattice structure in the composite ceramics were observed. At a relatively low temperature of 1510 °C, pressure of 50 MPa, and holding time of 5 min, the TiB 2 composite ceramic with 30 wt% TiC and 10 wt% Ti additions acquired an excellent strength of 727 MPa and a high toughness of 7.62 MPa m1/2. The improvement in strength and toughness was attributed to the mixed fracture mode, second phase strengthening, and increased energy consumption for crack propagation caused by the newly formed phases and fine TiC particles. In addition, the significant effects of the Ti and TiC addition contents on the densification temperature and mechanical properties of the composite ceramics were determined using analysis of variance (ANOVA). [ABSTRACT FROM AUTHOR]

Protein enriched snacks market is growing extensively due to the increasing demand for healthier and convenient food options. Extrusion cooking is the most common and commercially viable technique to manufacture protein enriched puffed snacks. However, the challenge lies in producing such snacks with uncompromised physical appeal. The present review summarizes the expansion, microstructure, and texture of extruded snacks produced at different protein levels to explain the role of protein content during extrusion and the effects of protein addition on final product quality, demonstrating the aforementioned challenge. Physical blowing agent (PBA)-assisted extrusion cooking is a recent modification to conventional food extrusion that enables better control and a certain degree of improvement to product physical quality. This review provides a detailed overview of the effects of various physical blowing agents on different phases in extrusion (e.g., melt expansion and melt shrinkage), and therefore the expansion, microstructure, and texture properties of the resultant snack products. Promising results were highlighted regarding the key improvement of physical properties, along with the additional benefits on nutritional qualities, presenting the great potential of this novel processing method. In order to provide some insights for future studies, the review further revealed the knowledge gap of PBA-assisted extrusion in food processing regarding the lack of studies focusing on how different PBA types, extrusion conditions, and feed formulas interact to affect extrudate expansion. Finally, the limited research in the applications of PBAs in manufacturing a broader range of extruded products, such as plant-based meat analogs, is identified. • Addition of protein to extruded snack formulas often impairs their physical quality. • The effects of different physical blowing agents in extrusion are explained. • Advantages of novel physical blowing agent-assisted extrusion cooking are stated. • Future work should focus on various blowing agents for broader applications. [ABSTRACT FROM AUTHOR]

In this study, a novel high‐entropy carbide‐based ceramic cutting tool was developed. The cutting performance of three kinds of high‐entropy carbide‐based ceramic tools with different mechanical properties for the ISO C45E4 steel were evaluated. Although the pure (Ti0.2Zr0.2Nb0.2Ta0.2Mo0.2)C0.8 ceramic cutting tool exhibited the highest hardness of 25.06 ± 0.32 GPa, the cutting performance was poor due to the chipping and catastrophic failure caused by the low toughness (2.25 ± 0.27 MPa m1/2). The (Ti0.2Zr0.2Nb0.2Ta0.2Mo0.2)C0.8–15 vol% cobalt cutting tool with highest fracture toughness (6.37 ± 0.24 MPa m1/2) and lowest hardness (17.29 ± 0.79 GPa) showed the medium cutting performance due to the low wear resistance caused by the low hardness. The (Ti0.2Zr0.2Nb0.2Ta0.2Mo0.2)C0.8–7.7 vol% cobalt cutting tool showed the longest effective cutting life of ∼67 min due to the high wear resistance and chipping resistance caused by the high hardness (21.05 ± 0.72 GPa), high toughness (5.35 ± 0.51 MPa m1/2), and fine grain size (0.60 ± 0.15 μm). The wear mechanisms of the cobalt‐containing (Ti0.2Zr0.2Nb0.2Ta0.2Mo0.2)C0.8 ceramic cutting tools included adhesive wear and abrasive wear and oxidative wear. This research indicated that the high‐entropy carbide‐based ceramics with high hardness and high toughness have potential use in the field of cutting tool application. [ABSTRACT FROM AUTHOR]

MnZn ferrite homogeneous fibers were synthesized via a simple solvothermal method and they were used as a reinforcing phase to prepare homogeneous-fiber-reinforced MnZn ferrite materials. The effects of MnZn ferrite homogeneous fibers (0 wt% to 4 wt%) doping on the microstructure, magnetic, and mechanical properties of MnZn ferrite materials were studied systematically. The results showed that MnZn ferrite homogeneous fibers exhibited high purity, good crystallinity, and smooth 1D fibrous structures, which were homogeneous with MnZn ferrite materials. Simultaneously, a certain content of MnZn ferrite homogeneous fibers helped MnZn ferrite materials exhibit more uniform and compact crystal structures, less porosity, and fewer grain boundaries. In addition, the homogeneous-fiber-reinforced MnZn ferrite materials possessed superior magnetic and mechanical properties such as higher effective permeability, lower magnetic loss, and higher Vickers hardness compared to ordinary MnZn ferrite materials. In addition, the magnetic and mechanical properties of homogeneous-fiber-reinforced MnZn ferrite materials first increased and then gradually decreased as the homogeneous fiber content increased from 0 wt% to 4 wt%. The best magnetic and mechanical properties of materials were obtained as the fiber content was about 2 wt%. [ABSTRACT FROM AUTHOR]

Correlations among the laser process, microstructure, porosity-related defects, and mechanical properties for selective laser melted AlSi10Mg alloy were investigated through experiments. A series of samples were produced with various laser parameters, and the porosity-related defects and microstructure were characterized by using X-ray computed tomography and scanning electron microscope. A model is proposed based on the energy density to reflect the evolution of the sample density with changing laser parameters; the optimal energy density level is evident when the sample density reaches 99.5%. Furthermore, the model has good applicability for both the volumetric energy density and deposited energy density parameters. In addition, defect evolution with increasing energy density, namely, the transition from lack of fusion defect domination to pore defect domination, is identified by considering anisotropy and sphericity factors simultaneously. The results also indicate that the porosity and Al-Si eutectic microcell have different effects on the mechanical properties. The negative correlation between the cell size and microhardness is built. The tensile strength highly depends on the porosity while the yield strength is mainly associated with the Al-Si eutectic structure. [ABSTRACT FROM AUTHOR]

The Cu/Al composite tube has been shown to significantly increase heat exchange capacity and reduce production costs which are extensively used in condensers, evaporators, refrigeration equipment, and so on. In this work, a Cu/Al composite tube was successfully fabricated by explosive welding technique. The interface morphology and grain information in the radial-axial direction (RD-AD) and radial-tangential direction (RD-TD) sections were investigated by optical microscopy (OM), scanning electron microscopy (SEM), and electron backscattered diffraction (EBSD). The results showed that the Cu/Al composite tube had a well-welded bonding interface without obvious defects. A flat wavy structure composed of fine grains was generated at the bonding interface in the RD-TD section while a small wavy structure was formed in the RD-AD section. In addition, the phase transformation occurred in both bonding regions which produced mainly CuAl and Khatyrkite metallic phases. Furthermore, the distinct impact pressure and plastic deformation patterns in the two sections lead to different dynamic recrystallization structures and texture distributions. [ABSTRACT FROM AUTHOR]

The cruciform welded joint is a weak position of filter press to cause fatigue failure under cyclic conditions. In this study, cavitation jet peening (CJP) treatment is proposed to improve the fatigue life of SAF2205 cruciform welded joints. The effects of different CJP treatment positions on the residual stress, microstructure, and microhardness were studied. The results show that different CJP treatment positions have different on residual stresses and fatigue life. The order of the residual stress in fracture position from large to small is the fully treated specimen, untreated specimen, one‐sided treated specimen, and diagonal treated specimen, which is exactly opposite to the order of fatigue life from large to small. After the diagonal CJP treatment, the fatigue life is increased by up to 242.19%, and the residual stress at the weld toe is reduced by more than 80%. A strengthening layer with thicknesses of about 400 μm is formed. [ABSTRACT FROM AUTHOR]

A new strategy was proposed to prepare in situ W 2 C particle reinforced (Ti,Ta,Nb,Zr,W)(C,N) high-entropy ceramics by the low chemical affinity between tungsten and nitrogen elements. High-entropy ceramics were prepared by in situ carbothermal reduction-nitridation and spark plasma sintering at elevated temperatures. The inferior chemical affinity between tungsten and nitrogen resulted in the formation of the W 2 C second phase in high-entropy carbonitrides during the reaction of metal oxides, carbon powder and nitrogen. The diffusion of tungsten and uniformly distributed W 2 C particles in the high-entropy carbonitride matrix enhanced the mechanical properties due to the high-entropy effect and dispersion strengthening mechanism. The high-entropy ceramic sintered at 2000 °C demonstrated a high hardness of 23.46 GPa at 9.8 N and an excellent fracture toughness of 4.59 MPa m1/2. The proposed technique was applicable to various carbonitride ceramic systems to prepare high-performance ceramic materials. [ABSTRACT FROM AUTHOR]

High-cycle fatigue (HCF) is a critical property of metastable β Ti alloys in aerospace applications. In this work, the HCF behavior and corresponding microscale deformation mechanisms of a metastable Ti-5Al-5Mo-5V-1Cr-1Fe (Ti55511) alloy with a basket-weave structure were investigated. HCF and its deformation mechanisms of a Ti55511 alloy were systematically studied in the deformed condition by using a scanning electron microscope (SEM), a transmission electron microscope (TEM), and electron backscatter diffraction (EBSD). It was found that the Ti55511 alloy exhibited an excellent HCF strength (107 cycles, Kt = 1, R = 0.06) of 738 MPa. The fractographic investigation demonstrated that fatigue striations and secondary cracks were the main features in the crack initiation zone. Dislocation analyses indicated that the HCF deformation of the basket-weave microstructure was mainly affected by the dislocation slipping of the primary α (αp) phase. In addition, the dislocation pile-up at the αp/βtrans interface led to crack initiation. EBSD analyses indicated that the prismatic type slip system of the αp phase was preferentially activated during the HCF deformation process of the Ti55511 alloy, followed by the basal type and pyramid type systems. [ABSTRACT FROM AUTHOR]

Recycled clay brick powder (RCBP) was used to replace partially cement to prepare composite cementitious materials, and the hydration kinetics and microstructure evolution of the composite cementitious materials were investigated by measuring the types of hydration products, hydration heat and microstructure. The results show that RCBP has little effect on the types of hydration products. However, at the later stage of cement hydration, the pozzolanic reaction occurs between RCBP and Ca(OH)2. Meanwhile, RCBP promotes the dispersion and dissolution of cement and provides many nucleation sites for C–S–H gel, increases the effective water-binder ratio and accelerates the heat release of cement hydration, however, the cumulative heat release decreases with the dosage of RCBP. In addition, RCBP can increase porosity at early stage of hydration, but the pozzolanic reaction between RCBP and Ca(OH)2 at the later stage of hydration would produce more hydration products, filling the pores, refining the pore diameter and improving the pore structure. Furthermore, RCBP affects the formation and microstructure of C–(A)–S–H gel, and promotes the formation of spherical C–(A)–S–H gel. [ABSTRACT FROM AUTHOR]

In this study, strontium (Sr) contaminated zeolite was sintered at 1500 °C for 1 h, and the radionuclide was fixed into the glass matrix. The phase evolution, microstructure, morphology, mechanical property, and chemical durability were investigated. The results exhibited that the solid solubility limit of the glass solidified body could reach up to 72 wt%. Compared with other solidified forms of radioactive wastes, the glass matrix synthesized in this study has good mechanical properties and chemical durability. Therefore, high-temperature sintering is a potential method for disposing of the radioactively contaminated zeolite waste. [ABSTRACT FROM AUTHOR]

Lithium aluminosilicate glass-ceramics are well known for good transparency, high fracture toughness, low thermal expansion, and good ion exchange ability. In this study, new transparent Li2O-Al2O3-SiO2 (LAS) glass-ceramics with petalite and β-spodumene solid solution as the major crystalline phases were invented for favorable mechanical properties and potential for application in the hollowware, tableware, container, and plate glass industries. Crystal phases are mainly influenced by the ratio of Al2O3 to SiO2 concentrations. The concentration of SiO2 required to form specific crystalline phases in the glass-ceramics is higher than that inferred from the ternary phase diagram. Al2O3 content is required to be sufficiently high for the formation of crystals, instead of balancing excess amounts of Li2O in the glass. The average transmittances of 2.0 ± 0.1 mm thickness samples in visible light regions (400–700 nm) can reach more than 80% with crystal sizes of 20–40 nm. Transmittance is significantly decreased for heat treatments around 710◦C, due to the high growth rate of β-spodumene solid solution crystals. Vickers hardness, indentation toughness, and crack probabilities of transparent LAS glass-ceramics are significantly improved compared with standard soda lime silicate glass, due to the crack bridging and deflection of crystal grains. [ABSTRACT FROM AUTHOR]

Vanadium-based alloys (VBAs) occupy a prominent position in the field of hydrogen storage materials due to their many advantages, including the ability to absorb/desorb hydrogen with high capacity under moderate conditions. However, the kinetic and thermodynamic properties of these alloys must be improved to expand the range of their practical applications. In this work, we systematically studied the influence of La doping on the microstructure and hydrogen storage performance of multicomponent VBAs. It was found that the as-cast multicomponent V 48 Fe 12 Ti 30 Cr 10 alloy prepared by arc melting contained micrometer/nanometer-sized crystals, which differed from the microstructure of traditional coarse-grained VBAs fabricated in the past decades. After the alloy was doped with La metal, its grains were refined into nanocrystallites with remarkable hydrogen absorption properties. This indicates that nanostructured VBAs can be realized by casting techniques, which is a traditional, low-cost, and engineering approach. The hydrogen storage capacity of the alloys first increased and then decreased with increasing La content. Furthermore, La doping considerably increased the alloy cycling stability. These findings can be used to develop novel hydrogen absorption materials for fuel cells with superior kinetic and thermodynamic properties. [Display omitted] • A multicomponent V-based alloy has a micron/nano-scale coexisted microstructure. • Doping La facilitates alloy grain refinement. • La-doped alloys exhibit excellent hydrogenation kinetics. • The phase transformation during dehydrogenation were studied in detail. • Doping La significantly improves the cycling stability of V-based alloys. [ABSTRACT FROM AUTHOR]

The microstructural evolutions of both uncarbonated and carbonated cement pastes subjected to various high temperatures (30 °C, 200 °C, 400 °C, 500 °C, 600 °C, 720 °C, and 950 °C) are presented in this study by the means of mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM). It was found that the thermal stabilities of uncarbonated cement pastes were significantly changed from 400 to 500 °C due to the decomposition of portlandite at this temperature range. More large pores and microcracks were generated from 600 to 720 °C, with the depolymerization of C-S-H. After carbonation, the microstructures of carbonated cement pastes remained unchanged below 500 °C and started to degrade at 600 °C, due to the decompositions of calcium carbonates and calcium modified silica gel. At 950 °C, both uncarbonated and carbonated cement pastes showed a loosely honeycombed microstructure, composed mainly of β-C2S and lime. It can be concluded that carbonation improves the high-temperature resistance of cement pastes up to 500 °C, but this advantage is lost at temperatures over 600 °C. [ABSTRACT FROM AUTHOR]

Microstructure evolution and hardening effect of pure tungsten and Wâ€"1.5%ZrO2 alloy under carbon ion irradiation are investigated by using transmission electron microscopy and nano-indentation. Carbon ion irradiation is performed at 700 °C with irradiation damages ranging from 0.25 dpa to 2.0 dpa. The results show that the irradiation defect clusters are mainly in the form of dislocation loop. The size and density of dislocation loops increase with irradiation damages intensifying. The Wâ€"1.5%ZrO2 alloy has a smaller dislocation loop size than that of pure tungsten. It is proposed that the phase boundaries have the ability to absorb and annihilate defects and the addition of ZrO2 phase improves the sink strength for irradiation defects. It is confirmed that the Wâ€"1.5%ZrO2 alloy shows a smaller change in hardness than the pure tungsten after being irradiated. From the above results, we conclude that the addition of ZrO2 into tungsten can significantly reduce the accumulation of irradiated defects and improve the irradiation resistance behaviors of the tungsten materials. [ABSTRACT FROM AUTHOR]

Here we report for the first time that Magnéli phase Ti 4 O 7 electrode with super performance is successfully prepared by hot-pressed sintering of single-phase submicron Ti 4 O 7 powders. The microstructure, mechanical properties, electrical conductivity and electrochemical performance of the Ti 4 O 7 electrodes were also investigated. Results show that the compact and homogeneous bulk Ti 4 O 7 without evident defects such as pores and cracks is achieved when the submicron Ti 4 O 7 powder was sintered at 1200 °C for 0.5 h. As a result, the bulk density of the Ti 4 O 7 reaches its theoretical value (4.323 g cm−3). Additionally, it has excellent physical and chemical properties, including the mean values of hardness and Young's modulus of 15.20 ± 0.42 and 247.40 ± 6.70 GPa, respectively, the Vickers-hardness of 1165.5 ± 9.5 HV, the highest known conductivity of 1252.5 S cm−1, and the widest known electrochemical stability window of 4.19 V in 1 M NaCl solution. [ABSTRACT FROM AUTHOR]

In this paper, we report successful fabrication of a 30-filament 150 m-length Nb3Al superconducting wire with very high critical current density (Jc) based on our second-generation reel-to-reel rapid heating and quenching (RHQ) heat-treatment equipment. The manufacturing process of 30-filament Nb3Al precursor wire and the effect of RHQ heat-treatment on the microstructure and Jc of Nb3Al superconducting wires are discussed. We have fabricated two wires with varying diameter such as 1.3 mm and 0.72 mm. For the Dia. of 1.30-mm Nb3Al wire, the critical current, Ic at 4.2 K and 12 T reaches 1078 A with optimized RHQ heat-treatment conditions. For the wire of finer Dia. 0.72 mm, it has the layer and non-Cu Jc of up to 3770 and 924 A/mm2 at 4.2 K and 12 T, respectively. Considering the excellent strain–stress tolerance of Nb3Al, along with competitive superconducting properties, Nb3Al superconductor is an attractive candidate for the large-scale superconducting magnet applications. [ABSTRACT FROM AUTHOR]

Coal gasification ash (CGA) is a solid waste produced by coal gasification. It can be used to produce autoclaved building materials because tobermorite, the main hydration product in such materials, can be formed from CGA and calcium oxide (CaO). In this study, tobermorite was prepared through the hydrothermal treatment of CGA. Given that residual carbon is usually present to some degree in CGA, its effects on the formation of tobermorite were specifically studied using X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and nitrogen adsorption–desorption tests. The results showed that tobermorite can be prepared from a CGA/calcium oxide mixture at 160°C without additional alkaline material. However, residual carbon can retard the transformation of calcium silicate hydrate into tobermorite and thus increase the required formation temperature while prolonging the formation time. With an increase in the residual carbon content, the morphology of the resulting tobermorite changes from needle-like and plate-like to irregular, which may also have a detrimental effect on the mechanical properties of the material. [ABSTRACT FROM AUTHOR]