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To enrich the use of protein-polysaccharide complex gel as texture assistance, we introduced a soy protein fibrils-chitin nanowhiskers complex gel system. Firstly, a stable positively charged chitin nanowhiskers (CNW) suspension and amyloid-like soy protein fibrils (SPF) were fabricated. We found that the self-assembled SPF and CNW formed complex with each other at pH 5.0–8.0 due to attractive interactions caused by their carrying opposite electrical charges. Then, the MTGase-induced SPF-CNW complex gel were formed and investigated by instrumental analysis. The results showed that the presence of CNW significantly increased the β-Sheet structure in complex gel and the rheological modules of complex gel were pH-dependent and showing G' > G" at all pHs. The SPF-CNW complex gel showed a strong and elastic textural property during compression test at pH 6.0. Meanwhile, the frequency scan showed that the SPF-CNW system is less dependent on the frequency and belonged to the typical physical gel. According to the results of SEM and CLSM images, the SPF, CNW and complex gel presented spherical shape, rod shape and linear alignment microstructure, respectively. We inferred that the CNW provided a framework for gel formation and introduced rigidity to the SPF gel. Thanks to the attractive interactions, the SPF molecules were attached to the growth of CNW to form a longer fiber structure. After the gelation process, the aggregates further interacted with each other and finally form complex gel with linear, ordered and compact microstructure. [Display omitted] • Self-assembled SPF and CNW formed complex due to attractive interactions. • SPF-CNW complexes exhibited strong colloidal behavior and strong springiness. • The rheological modules of gel was pH-dependent and showing G' > G" at all test pH. • CNW provided a framework for gel formation and introduced rigidity to the SPF gel. [ABSTRACT FROM AUTHOR]

This study investigates the damping properties of Cu–Al–Mn shape memory alloys (SMAs) with various chemical compositions and the effects of the addition of quaternary alloying elements Ag and Nb on the microstructure, martensitic transformation behavior, and damping capacity of SMAs. Compared to other Cu–12Al– x Mn (x = 4–7 wt%) SMAs, Cu–12Al–5Mn has a more significant inherent and intrinsic internal friction (IF PT + IF I) peak above room temperature. The addition of Ag or Nb to Cu–12Al–5Mn reduced the grain size, thereby increasing the hardness of the alloys; however, the damping capacity and temperature of the IF PT + IF I peak decreased simultaneously. The addition of Ag to Cu–12Al–5Mn significantly reduced the damping capacity (IF PT +IF I peak) because of the notable decrease in the amount of transformed martensite. Moreover, the addition of Nb to Cu–12Al–5Mn caused the AlNb 3 phase to precipitate, limiting the mobility of the martensite variant interfaces and slightly decreasing the damping capacity (IF PT + IF I peak). Among the Ag- and Nb-doped Cu–12Al–5Mn SMAs, Cu–12Al–5Mn–1 Nb showed not only a significantly higher hardness but also a higher IF PT + IF I peak, with tan δ exceeding 0.01 at approximately 50 °C. [Display omitted] • In Cu-based SMAs, damping capacity depends on microstructure and the volume fraction of the transformed martensite. • Alloying elements with different mechanisms affect the damping performance of Cu-based SMAs. • In Cu-based SMAs, both damping capacity and mechanical strength improve by optimizing chemical composition. [ABSTRACT FROM AUTHOR]

Abstract: The solidified structure of ZK60 magnesium alloys in the presence and absence of electromagnetic stirring during the solidification process was compared, and the precipitates of ZK60 magnesium alloys were analyzed after a solution heat treatment using optical microscopy, micro-hardness analysis, X-ray diffraction and scanning electron microscopy. The results showed that the microstructure of cast alloys under a low-frequency alternating magnetic field (LFAMF) was mainly composed of a primary crystalline Mg matrix and a non-equilibrium eutectic structure (Mg+MgZn+MgZn2). In comparison with the microstructure observed in the absence of the electromagnetic field, the eutectic network structure on the grain boundary under low-frequency alternating magnetic field was finer and exhibited a more uniform grain distribution. The grains under the LFAMF were refined in comparison with those under no electromagnetic field before the solution heat treatment, and the former grain distribution was more uniform than the latter after the solution heat treatment. The more uniform grain distribution is because the solution heat treatment is conducive to the dissolution of the second phase particles. The hardness exhibited a downward trend with increasing solution heat treatment time. Under the same solution heat treatment, the hardness value of the samples prepared under the LFAMF was lower than those prepared in the absence of the electromagnetic field. In contrast, the mechanical properties of alloys prepared under the LFAMF were better than those prepared in the absence of the electromagnetic field. [Copyright &y& Elsevier]

Abstract: A phase field dynamic model was developed and used to investigate the effects of dislocations and applied strain on the precipitation behavior and microstructure evolution of model binary alloys. The simulations show that the local microstructure depends not only on the relative magnitude of the dislocation stress and the stress induced by the applied strain, but also on the composition and magnitude of the stress. Its also shown that the applied strain makes the phase decomposition quickly. The results suggest that the microstructure of an alloy and its evolution may be controlled by finding suitable combination between dislocation, applied strain and composition, and the theoretical calculations are helpful in predicting what those combinations should be. [Copyright &y& Elsevier]

Abstract: Coordination polymers [Hg(L 2 )Cl2] n (1) and {[Hg2(L 2 )Cl4](DMF)} n (2) have been assembled from Hg(II) chloride and a novel tripyridyltriazole tecton 3,4-bis(2-pyridyl)-5-(4-pyridyl)-1,2,4-triazole (L 2 ) in different solvent media. Both complexes have been characterized by IR, microanalysis, powder X-ray diffraction, and thermogravimetric analysis. Single crystal X-ray diffraction indicates that the L 2 ligands take the (η3, μ2) and (η4, μ3) binding modes in 1 and 2, respectively, which connect the Hg(II) centers to afford linear and ladder-like 1D arrays. Interestingly, complex 1 exhibits strong solid state fluorescent emission at room temperature due to the intraligand transitions, whereas complex 2 is non-fluorescent. [ABSTRACT FROM AUTHOR]

Abstract: This work firstly presents detailed evidence of the fcc-type miscibility gap in the Cu–Ni–V system at temperatures between 1000°C and 1100°C. The phase equilibria, phase transformation behavior and microhardness of the (Cu0.5Ni0.5)100−xVx (at.%) (x=2, 4, 6, 8, 10, 12) alloys have been investigated by electron probe microanalysis, X-ray diffraction, differential scanning calorimetry and Vickers hardness tester, confirming that the fcc-type miscibility gap exists in the Cu–Ni–V system at temperatures between 1000°C and 1100°C. The obtained results will not only help to well understand the strengthening mechanisms in the Cu–Ni–V alloys at high temperatures, but also to effectively develop new high-temperature spinodal-hardened Cu–Ni–V base alloys in the future. [ABSTRACT FROM AUTHOR]

Abstract: (Pb0.87Ba0.1La0.02)(Zr0.68Sn0.24Ti0.08)O3 anti-ferroelectric ceramics with various amounts of excess PbO have been fabricated by the conventional solid-state reaction process and the hot-press sintering method, and the dependence of microstructure, ferroelectric and dielectric properties on sintering approaches and lead volatilization conditions has been studied. When an appropriate quantity of excess PbO is added, the lead volatilization effect can be compensated and the content of pyrochlore phase is decreased. Hot-pressed anti-ferroelectric ceramics exhibit much higher densities than conventionally sintered samples. The spontaneous polarization and maximum dielectric constant of the AFE ceramics decrease when the hot-press sintering method is used. The dielectric loss can be obviously reduced by using the hot-press sintering method and adding a proper amount of excess PbO. The systemic investigation of the lead volatilization effect and the hot-press sintering method will contribute to the development of high properties of anti-ferroelectric ceramics in practical applications. [Copyright &y& Elsevier]

Abstract: The phase equilibria in the Co–W–V ternary system were experimentally investigated by optical microscopy (OM), electron probe microanalysis (EPMA) and X-ray diffraction (XRD) on the equilibrated alloys. Three isothermal sections of the Co–W–V ternary system at 1100°C, 1200°C and 1300°C were determined, and no ternary compound was found in this system. In addition, a novel phenomena induced by the liquid phase separation in the Co–W–V alloys was firstly discovered, suggesting that a stable liquid miscibility gap exists in the Co–W–V ternary system. The newly determined phase equilibria and firstly discovered phase separation phenomena in the Co–W–V system will provide important information for the development of Co–W based alloys. [Copyright &y& Elsevier]

Abstract: A statistical second-order two-scale (SSOTS) method is established in a constructive way for predicting the thermomechanical properties of statistically inhomogeneous materials. For this kind of composite materials, the complicated micro-characteristics of inclusions, including their shape, size, orientation, spatial distribution, volume fraction and/or material properties and so on, lead to changes of the macroscopic thermomechanical properties, such as stiffness, coefficient of thermal expansion and strength of material. In this paper, a statistical model at an arbitrary position of the composite material is defined to represent the microstructure of the statistically inhomogeneous media at first. And then, the statistical second-order two-scale analysis formulation is derived. Finally, the numerical results for some statistically inhomogeneous composites are calculated by SSOTS algorithm, and compared with the data by experimental and theoretical methods. [Copyright &y& Elsevier]

The design and fabrication of devices that based on adaptive soft matter with the autonomous transduction of environmental and field signals is an interesting area of material science and device engineering. Additive manufacturing, also known as 3D printing, has gained great attention as it allows the creation of complex 3D geometries with precisely prescribed microarchitectures, which enable new functionalities or improved performance. Here, we report on poly(ethylene glycol) diacrylate hydrogel microstructures with excellent humidity responsiveness by 3D printing of two-photon photopolymerization. The voxels of fabricated hydrogel microstructures have controllable crosslinking density because adjusting fabrication parameters, therefore controllable humidity-driven swelling ability can be achieved. Using the proper parameters, we present an array of microstructures which can realize the function of nano-interconnected network and a hydrogel microstructure with pores to mimic the open and close of the stomata of plants. Based on a flexible two-steps fabrication method and the combination of active and inert materials, binary encoding micropillar arrays and joint-like cantilever microstructure have been easily fabricated. The humidity-responsive actuation of hydrogel microstructures is repeatable and stable over 10000 cycles. This kind of composite hydrogel microstructures may lead to great promise for the diverse applications such as sensors, actuators or construction of soft robots. [ABSTRACT FROM AUTHOR]

The influence of Gd element and solution treatment on the microstructure of AZ31 alloy was investigated in this paper. The microstructure and phase composition were characterized by OM, SEM, EDS and XRD. The results indicate that Mg 17 Al 12 eutectic phase, scattered along the grain boundary, is suppressed effectively with Gd addition and the acicular Al 2 Gd superlattice with lamellar distribution is formed. Furthermore, the grain size of AZ31 alloy is also refined with Gd addition. In the subsequent process of solution, the migration and growth of Al 2 Gd phase conforms to Ostwald Ripening Theory. The morphology of Al 2 Gd phase becomes granular and scatterd in matrix uniformly after solution for 16 h at 813 K. [ABSTRACT FROM AUTHOR]

• Annealing at different temperatures was used on cold rolling fe-13cr-4al-2mo thin-walled tubes. • The microstructure and axial tensile properties of the samples before and after annealing were measured. • The annealed samples were embrittled by aging, and the enhanced particles and hardness were characterized. • The strengthening mechanism of FeCrAl alloy at room temperature and failure mechanism at high temperature were investigated. FeCrAl alloy has great application potential to replace traditional zirconium alloy as an accident-tolerant fuel (ATF) candidate material. In this study, Fe-13Cr-4Al-2Mo-0.65Nb-0.4Ta alloy was prepared into a thin-walled tube with a diameter of 9.5 mm and a wall thickness of 0.35 mm by cold rolling. The effects of different annealing temperatures on the microstructure morphology, texture growth direction, and mechanical properties of FeCrAl alloy were studied., alloy underwent recovery and recrystallization with increasing annealing temperature, and the grain size increased. The theoretical calculation showed that the pinning action of Fe2Mo4C and Fe2Nb increased the dislocation density, and the interaction with the dislocation increased the room temperature strength. The addition of Ta led to the formation of more second-phase precipitates at the grain boundary, which hindered the growth and refined grains. The high-temperature stable second phase provided sufficient temperature strength for the alloy. [ABSTRACT FROM AUTHOR]

Abstract: The precision of orientation to target placement during invasive therapy is mainly influenced by tool–tissue interaction. In this study, we aim to investigate a transparent Poly (vinyl alcohol) (PVA) hydrogel as tissue-equivalent material which is used in accurate surgical insertion research. The PVA hydrogel with specified formula was prepared by means of physical and chemical crosslink. The effects of chemical composition and synthesis technique on the biomechanical property, density and micro-structure morphology of PVA materials have been investigated in detail. It can be concluded that when PVA concentration is 8g/dl, the NaCl concentration is 4wt.%, with mix water/DMSO solvent, prepared under 7 freeze/thaw cycles, the material has the most similar properties with kidney tissue. Experimental results demonstrate that this tissue-equivalent material could be used in the ex vivo insertion accuracy test for robot-assisted percutaneous intervention and surgical training in minimally invasive surgery (MIS). [Copyright &y& Elsevier]

Abstract: Pb(Zr0.9Ti0.1)O3 pyroelectric thick films adding various amounts of the sintering aids Bi2O3–Li2CO3 have been deposited on the substrates Al2O3 by the screen-printing process, and the dependence of microstructure, dielectric and pyroelectric properties on the content of sintering aids has been studied. When the amount of Bi2O3–Li2CO3 increases from 0wt% to 5.4wt%, the sintering temperature of the thick films decreases from 1100°C to 900°C, and the grain size and the lattice constant decrease either, but the density and the dielectric constant increase. The Pb(Zr0.9Ti0.1)O3 thick film with 5.4wt% of Bi2O3–Li2CO3 sintered at 900°C has the maximum pyroelectric coefficient 10.51×10−8 C/cm−2 K−1 and the highest figure-of-merit 10.58×10−5 Pa−0.5. [Copyright &y& Elsevier]

Abstract: Micrometer Li1.05Mn1.95O4 has been synthesized by solid state reactions with the nano-Mn3O4 as a precursor. X-ray diffraction, scanning electron microscopy and laser particle sizer are employed to investigate the structures, morphologies and particle size distributions of the powder. The micrometer Li1.05Mn1.95O4 exhibits good rate performance at room temperature with a specific capacity of 98.4mAhg−1 at 5C. The Li1.05Mn1.95O4/Li half cell also shows good cycling performance at elevated temperature with 90.5% of its initial capacity retained after 100 cycles at 1C. At −20°C, the Li1.05Mn1.95O4 delivers a stable cycling performance with a specific capacity of 84.5mAhg−1, being 84.1% of the capacity at room temperature. The cyclic voltammetry (CV) and rate performance measurements illustrate an increasing polarization with decreasing the temperature. In addition, the diffusion coefficients of lithium ions in Li1.05Mn1.95O4 at various temperatures (25, 0, −10 and −20°C) are determined to be in the magnitude of 10−10 to 10−12 cm2 s−1 by cyclic voltammetry (CV) method. [Copyright &y& Elsevier]

T-joints of an α titanium alloy were successfully welded by friction stir welding, and the evolution of microstructure, texture and mechanical properties were investigated. Results show that dynamic recrystallization occurs in the stir zone, and the grain morphology depends on whether the welding temperature exceeds β transus. The microhardness of the welded joint shows a W-shaped profile, with the highest values in the stir zone and the lowest ones in the heat-affected zone. The joint tensile strength in the skin direction is significantly higher than that in the stringer direction. As the rotation speed or the welding speed increase, the tensile strength of the joint increases to a maximum, followed by a drop in both the skin and stringer directions. Similarly, the joint impact toughness increases first and then decreases with the increase of rotational speed or welding speed. The impact fracture of the typical joint with 850 rpm-50 mm/min is ductile dominated by dimples. In addition, the corrosion resistance of welded joint is improved compared to that of the base material. • The welding temperature plays a decisive role in the final microstructure of the T-joint. • The stir zone is textured due to the dynamic recrystallization and shear action of the FSW tool. • With the increase of rotation speed, the microhardness of the joint decreases gradually. • As the rotation speed increasing, the tensile strength of the T-joint has a maximum value. • The impact toughness of the T-joint is sensitive to the rotation speed and welding speed. [ABSTRACT FROM AUTHOR]

Fracture toughness of friction stir welded titanium alloy joints was investigated using Compact tension (CT) toughness specimens. The fracture toughness slightly decreases to about 90% of the fracture toughness of base metal. The fracture surface was mainly ductile fracture mechanism with a large number of dimples. The crack propagation path was straight and mixed with intergranular and transgranular fracture. The stir zone of joint has a large number of fine ɑ grains with some dislocations. For texture, the stir zone has hard orientation {0002} <11 2 ¯ 0>, the directions of cylinder and plate thickness are parallel. The reduction of fracture toughness in the stir zone is mainly related to microstructure and texture. [ABSTRACT FROM AUTHOR]