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In this study, the High Velocity Oxygen Fuel (HVOF) technology was utilized to fabricate HEA coatings composed of Al x CoCrFeNi (x = 0.4, 0.7, 1.0), followed by subsequent vacuum annealing conducted at temperatures spanning 500, 700, 900, and 1100 ℃. The microstructure, phase compositions and mechanical properties of HVOF-sprayed Al x CoCrFeNi HEA coatings before and after vacuum annealing were analyzed. Our findings indicate that the HVOF-sprayed Al x CoCrFeNi HEA coatings demonstrate a single solid solution phase (either FCC or BCC). As the Al content rises, the phase structure of the HEA coating shifts from FCC to BCC, resulting in increased hardness, H/E ratio, and H3/E2 ratio. After undergoing vacuum annealing at 500℃, the Al x CoCrFeNi HEA coatings retain the identical microstructure and phase composition as the as-sprayed state. With increasing annealing temperature, the BCC phase to FCC phase transformation occurs and the microstructure coarsens. After vacuum annealing at 500℃, the hardness, H/E and H3/E2 values of the coatings are most significantly enhanced due to the grain boundary dislocation source strengthening. At 700 and 900℃, the mechanical properties of the coatings are also improved as a result of the existence of the σ phase. However, at 1100℃, the mechanical properties of the coatings decline due to phase transformation and grain coarsen. This indicates that HVOF technology and appropriate annealing process may be a new strategy for designing high-performance HEA coatings, which has potential applications in aerospace, geological drilling, marine ships and other fields. • Appropriate annealing post-treatment might be a novel strategy for designing AlxCoCrFeNi HEA coatings with high performance. [ABSTRACT FROM AUTHOR]

In this study, a series of CoCrFeMnNiC x (0–0.8 at% C) high-entropy alloys (HEAs) were prepared by vacuum arc melting and subsequently vacuum annealed at 800°C or 1000°C for 120 h. The aim was to investigate the microstructure evolution and corrosion behavior of the as-cast and annealed CoCrFeMnNiC x alloys in a neutral corrosion solution. Experimental results revealed that the addition of C can refine the as-cast dendrite structure, with an optimal C content of 0.4 at%. Annealing treatment led to a decrease in C solubility in the face-centered cubic (FCC) phase, resulting in the precipitation of carbides. In a 3.5 wt% NaCl neutral solution, the as-cast alloy containing 0.4 at% C exhibited the highest corrosion resistance. After annealing at 1000°C, the alloy's pitting potential and corrosion resistance were further improved. The corrosion behavior of both the as-cast and annealed CoCrFeMnNiC x alloys was primarily composed of pitting and intergranular corrosion, although the dominant mechanism varied among these alloys. This study establishes a correlation between microstructure evolution and corrosion behavior, providing insights for the design of high-entropy alloys with superior corrosion resistance. • Dendrite structure evolution of CoCrFeMnNiC x alloys is characterized. • The precipitation of carbides is related to the carbon content and annealing temperature. • Intergranular corrosion phenomenon was clearly observed. • The relationship between microstructure evolution and corrosion resistance was clarified. • Slight changes in grain boundaries and grains can lead to different corrosion behaviors. [ABSTRACT FROM AUTHOR]

Difficulty in shaping and deformation impedes the application of 60NiTi alloy showing high hardness and high corrosion resistance. To promote the application of 60NiTi alloy, a 60NiTi film was deposited on 316 stainless steel substrate by magnetron sputtering. The results showed that a 60NiTi film with excellent adhesion property and excellent thermal-shock resistance could be prepared by sputtering at 1.5 A and then annealing at 500 °C. The hardness of annealed 60NiTi film was comparable to bulk 60NiTi alloy, and its corrosion resistance was much better than that of the bulk 60NiTi alloy. [ABSTRACT FROM AUTHOR]

Nanocrystalline Ti/AZ61 magnesium matrix composite, prepared by mechanical milling, was annealed in the temperature range of 573–723 K for various durations. During annealing treatment, diffusion of Al and Ti elements, formation of precipitates and grain growth behavior were observed and the evolution of hardness was obtained. Based on microstructural evolution, the mechanism for the precipitating of Ti and Al from magnesium matrix was analyzed. And the corresponding schematic illustration of microstructural evolution model was proposed. By the observation from high-resolution transmission electron microscopy, it was found that dispersing nanometer sized particulates, precipitated from Ti and Al supersaturated Mg solid solution, pined up magnesium grain boundaries. During annealing treatment, the nano-scaled precipitates together with original submicron Ti particulates hindered the movement of grain boundaries. Thus, the thermal stability for magnesium grains was improved. After annealing treatment at 723 K for 600 min, this magnesium matrix composite with the average grain size of ∼93 nm was still nanocrystalline. In addition, influence of temperature and time on hardness was investigated. After annealing treatment at 723 K for 600 min, the hardness of annealed Ti/AZ61 composite is approximately 116 HV, presenting outstanding thermal stability. [ABSTRACT FROM AUTHOR]

Novel high-entropy alloys (HEAs) coatings deposited using physical vapour deposition technique are potential candidates of protective coatings due to their excellent performance. However, the correlation between properties and microstructure of HEAs coatings has not been completely established and the hardening mechanism remains unclear. In this paper, the AlCrNbSiTi HEA coatings were deposited under different bias voltages by radio-frequency magnetron sputtering. The morphology, chemical composition, structure, mechanical properties and thermal stability are discussed in detail. All coatings exhibit smooth surface without obvious elemental segregation and the columnar structure tends to densify with increasing bias. The coatings possess a nanocomposite structure of amorphous-nanocrystalline silicides, in agreement with the results calculated based on three phase prediction parameters (ΔH mix : enthalpy of mixing, δ: atomic size difference and Ω: ratio of entropy of mixing ΔS mix to ΔH mix). The coating deposited at bias of − 50 V presents optimal mechanical properties with nanohardness of ∼15.2 GPa, scratch crack propagation resistance of 1042 N2 and wear rate of 5.4 × 10−8 mm3N−1m−1. Annealing treatment further unravels that the presence of hard silicides is the hardening mechanism of coatings with super-hardness of ∼24 GPa. The results indicate that the AlCrNbSiTi coating is a promising protective coating with broad industrial application prospects. • Structure of coatings is a nanocomposite of amorphous-nanocrystalline silicides. • Annealing unravels hardening mechanism of coatings is presence of hard silicides. • Coating deposited at − 50 V exhibits a super-hardness of 24 GPa after annealing. • Wear mechanism of coatings is revealed with a lowest wear rate of 5.4 × 10−8 mm3/Nm. [ABSTRACT FROM AUTHOR]

In the present work, a Ti-40Zr-12Ta (in atom percent, at%) alloy with the spinodal decomposition was designed based on the isothermal section of the Ti-Zr-Ta ternary phase diagram. The alloy was first solid solution treated at 1000 °C and then cold rolled with a thickness reduction of 70% at room temperature. After that, the as-rolled samples were annealed at the temperatures ranging from 500 °C to 900 °C, and the effects of annealed temperature on the microstructure and mechanical properties were investigated. It is found that the spinodal decomposition occurred in the alloy at the temperature ranging from 500 °C to 700 °C, leading to the formation of the periodically distributed Ta-rich (β 1) and Ta-lean phases (β 2). The as-rolled Ti-40Zr-12Ta alloy exhibited a relative high strength due to the work hardening and solid solution strengthening. Annealing treatment at 500 °C promoted the strength of the alloy but significantly decreased its plasticity due to the formation of nano-scale isothermal ω phases. The sample annealed at 700 °C exhibited good tensile mechanical properties, and the modulated structure introduced by spinodal decomposition and TRIP effect contribute to the improvement of its strength and plasticity. • Ti-40Zr-12Ta with the spinodal decomposition was designed according to isothermal section of the phase diagram at 727 °C. • The spinodal decomposition occurred in the alloy during annealing at the temperatures ranging from 500 °C to 700 °C. • Stress-induced martensitic phase transformation occurred in the alloy at 700 °C, which contributed to the plasticity. • The formation of the nanoscale periodically distributed β 1 and β 2 by spinodal decomposition contributed to the strength. [ABSTRACT FROM AUTHOR]

FeSiAl soft magnetic composites (SMCs), which are widely used in electromagnetic applications, can be described as FeSiAl particles surrounded by electrical insulating layers. In general, good insulation is required to minimize eddy currents within SMCs in high frequency applications. In this work, FeSiAl-based SMCs with uniform single insulation layer of AlN/Al 2 O 3 were prepared by high-temperature selective nitridation and oxidation. For comparison, SMCs with double layers of phosphate-resin or phosphate-silane were produced by traditional chemical process. Their magnetic properties were systematically studied. The results revealed that the core insulated by AlN/Al 2 O 3 with high electrical resistivity had much better stability in the real part of permeability μ′ than double layer insulated cores with respect to frequency in the range of 100 kHz to 28 MHz. In addition, the FeSiAl-AlN/Al 2 O 3 core had higher quality factor Q at higher frequency than other cores. The investigation of the effects of annealing process up to 600 °C on the cores indicated that the magnetic properties of FeSiAl-AlN/Al 2 O 3 cores were strongly improved in terms of μ′, Q, total core loss P tot and coercivity H C mainly on account of the hysteresis loss reduction by stress relaxation and defects elimination. By contrast, annealing treatment had less positive effects on the properties of the cores with double insulating layer. In addition, the microstructure, composition and thermal stability of the AlN/Al 2 O 3 insulated particles were characterized by Scanning Electron Microscopy, Transmission Electron Microscopy, X-Ray Diffraction, X-ray Photoelectron Spectroscopy and Derivative Thermogravimetric Analysis, respectively. [ABSTRACT FROM AUTHOR]

The effects of Fe content and annealing temperature on the microstructure, thermal stability and soft magnetic properties of Fe-rich Fe 83.5+ x B 15- x Cu 1.5 (x = 0.5, 1.0, 1.5, 2) alloys were investigated. The results show that when the Fe content is going up to 85%, alloys still have the capability of forming a single amorphous phase. After that, glass-forming ability (GFA) is weakened and crystalline phase appears. In terms of thermal stability of alloys, the increase in Fe content is beneficial to obtain a larger crystallization temperature interval (Δ T x = 144.4 ℃), which is conducive to the process of heat treatment and the preparation of amorphous/nanocrystalline soft magnetic materials. The optimum annealing treatments (430 ℃×10 min) can yield the high saturation magnetization (M s) of 208 emu/g, which is comparable to the one of alloy Fe-Si 3 wt%. • When the Fe content increase to 85 at%, alloys still have the GFA of forming a single amorphous phase. • T x1 increase with the increase of Fe content, T x2 almost stay still with increase of Fe content. • The soft magnetic properties M s and H c of 208 emu/g and 35 A/m are achieved in Fe 85 B 13.5 Cu 1.5 alloy. [ABSTRACT FROM AUTHOR]

We report on the influence of the annealing temperature on the crystal structure phase change, effective anisotropy energy and magnetization reversal of electrodeposited Fe 3 Ga nanowires (NWs) with diameter of 80 nm. Scanning transmission electron microscopy (STEM) energy-dispersive X-ray (EDX) spectroscopy technique for the elemental mapping of Fe 3 Ga NWs showed clearly the homogeneous distribution of Fe and Ga. These NWs are highly aligned to each other and exhibits high geometrical aspect ratio. The crystal structure of these nanowires shows strong dependence on the sintering temperature. X-ray diffraction reflects the highly textured A2-disorderd phase with precipitates of DO 3 and L1 2 phase for as-synthesized Fe 3 Ga NWs. As the annealing temperature increases, the intensity of strong disordered phase A2 or short range order phase DO 3 suddenly decreases and grains are textured along the stable L1 2 phase with small precipitates of DO 3 phase. As a result of these structural changes, magnetization reversal mode switches from transverse to a combination of transverse and vortex modes. Angular magnetic response at room temperature is employed to identify the magnetization reversal modes for Fe 3 Ga NWs. Temperature dependent coercivity response can be understood in terms of thermal activation over an energy barrier with a 3 2 – power dependence on the field. [ABSTRACT FROM AUTHOR]

Hexagonal SrFe 12-x Al x O 19 (x = 0, 0.2, 1, 2, 4) powders were prepared via mechanochemical activation and subsequently calcined at different temperatures (between 900 °C and 1300 °C). Afterwards the powders were milled by high energy milling and annealed at 1000 °C in NaCl to obtain ultrafine nano-particles. The particle size, measured by scanning electron microscopy (SEM), varied between 50 nm and few micrometers depending on Al 3+ substitution and calcination temperature. Average crystallite size, determined by X-ray diffraction (XRD), decreases from 330 nm ± 30 nm (x = 0) to 70 nm ± 10 nm (x = 4) by substitution of Fe 3+ by Al 3+ for optimized calcination temperature of 1100 °C. Furthermore coercivity measured by SQUID magnetometry increases from 420 kA/m (x = 0) to 970 kA/m (x = 4). A maximum saturation magnetization of 74 Am 2 /kg (x = 0) was observed. With substitution of Fe 3+ by Al 3+ saturation magnetization decreases monotonously to 28 Am 2 /kg (x = 4). Annealing in NaCl matrix at lower temperatures compared to calcination temperatures leads to a further increase of coercivity. At the same time saturation magnetization increases for SrFe 12-x Al x O 19 (x = 0, 1) by NaCl annealing treatment. Additionally, we discuss the initial magnetization curves of SrFe 12 O 19 and SrFe 8 Al 4 O 19 after different processing steps with respect to the specific reversal mechanism of hexaferrites. The here proposed processing route enables a simultaneous enhancement of coercivity and saturation magnetization as compared to conventional ceramic method [1,2] . The presented processing route can solve challenges of conventional manufacturing steps towards single domain grains in rare earth free SrFe 12-x Al x O 19 for higher coercivity and could enable an improved industrial production process. [ABSTRACT FROM AUTHOR]

La 1 − x Pr x MgNi 3.6 Co 0.4 ( x = 0–0.4) alloys are prepared by vacuum induction melting. The phase composition and microstructure of the as-cast alloys is characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The gaseous hydrogen absorption capacity of the alloys was measured by an automatically controlled Sieverts apparatus. The results indicate that the as-cast alloys consist of two phases of LaMgNi 4 and LaNi 5 . The maximum gaseous hydrogen storage capacity of the La 1 − x Pr x MgNi 3.6 Co 0.4 ( x = 0–0.4) alloys is 1.768, 1.745, 1.721, 1.681 and 1.653 wt%, respectively, under 3 MPa H 2 at 373 K. But the hydrogen storage capacity after 20 cycles decays off to 0.746, 0.843, 0.947, 1.003 and 1.10 wt%, respectively. In order to reveal the mechanism of rapid degradation of the capacity, the structures of the alloys before and after hydrogen absorption/desorption cycle were analyzed. SEM observation displays that the micro-cracks can be clearly seen on the surface of the alloy particles after 20 cycles. XRD detection finds that the repeated hydrogen absorption/desorption cycles give rise to a obvious broadening of the diffraction peaks of the alloys, exhibiting a typical amorphous structure, which is termed as hydrogen-induced amorphization. The La 1 − x Pr x MgNi 3.6 Co 0.4 ( x = 0–0.4) alloys after 20 cycles were annealed at 623 K for 8 h, finding that the hydrogen storage capacity of the alloys recovers to 1.348, 1.365, 1.50, 1.485 and 1.30 wt%, respectively, under 3 MPa H 2 at 373 K. [ABSTRACT FROM AUTHOR]

The as-cast Ti 1.02 Cr 1.1 Mn 0.3 Fe 0.6 alloy for hybrid hydrogen storage vessel application was annealed at different temperatures (873 K, 973 K, 1123 K, 1173 K) for 2 h, and annealed at 1123 K for different time (2, 5, 8 h) respectively, and their microstructure and hydrogen storage properties were investigated systematically. The results show that the as-cast alloy has a single C14 Laves phase, and all annealed alloys consist of a C14 Laves main phase and a secondary phase. After annealing at different temperatures for 2 h, the hydrogen absorption pressure at 298 K decreases, however, the maximum hydrogen storage capacity and desorption pressures at 318 K decrease slightly too. As the annealing time extends, the hydrogen absorption plateau pressure at 298 K and hydrogen desorption plateau pressure at 318 K increase, and the hydrogen desorption capacity increases first and then decreases, which reaches the highest desorption capacity of 1.721 wt.% at the annealing time of 5 h. Among the studied alloys, the alloy annealed at 1123 K for 5 h has the best overall properties for hybrid hydrogen storage application, its hydrogen absorption plateau at 298 K is 29.09 MPa, its hydrogen desorption plateau pressure at 318 K is 45.12 MPa, its hydrogen storage capacity is 1.721 wt.% and its dissociation enthalpy (Δ H d ) is 17.78 kJ/mol H 2 . [ABSTRACT FROM AUTHOR]

In this study, we investigate the growth of Cu2O thin-films on fluorine doped tin oxide (FTO) substrate by electrochemical deposition. We examined the effect of annealing temperatures as well as annealing durations on the morphological, structural, photoelectrochemical and optical properties of Cu2O thin-films grown with pH value 11. Our work shows that Cu2O thin-films grown at pH 11 have preferred growth orientation towards (111) and those films have higher photocurrent density. The photoelectrochemical property of the Cu2O thin-film was found highly depended on their crystallinity and morphology. [ABSTRACT FROM AUTHOR]

Highlights: [•] Effect of processing parameters on the properties of MP powder cores was studied. [•] Effective magnetic permeability was enhanced from 45 to 160 after annealing. [•] A core loss of 780mw/cm3 (100kHz, 100mT) was obtained. [Copyright &y& Elsevier]

Highlights: [•] Magnetomechanical Hysteresis Effect causes the higher damping value of Fe–Cr alloys. [•] Decreasing internal stress makes the magnetostriction coefficient higher. [•] Magnetomechanical effect and damping capacity decrease due to the domain structures. [ABSTRACT FROM AUTHOR]

Highlights: [•] As-cast and annealed La1.8Ti0.2MgNi8.7Al0.3 alloys are prepared. [•] The enthalpies of the alloys are close to −30.6kJ/mol H2 of LaNi5 compound. [•] Annealed alloys exhibit higher hydrogen capacity and lower plateau pressure. [•] The cycle life and high rate dischargeability are improved markedly by annealing. [•] The appropriate annealing temperature for the alloy studied is 900°C. [ABSTRACT FROM AUTHOR]

Abstract: The reactivity of Cu2+ ion concentration in Ni–Zn spinel matrix fabricated using solution combustion route has been investigated. The specimens of nanocrystalline Ni0.8− x Cu x Zn0.2Fe2O4 (x =0.0⩽0.6 with steps of 0.2) exhibits single phase cubic structure. The detailed studies regarding the physico-chemical stability, crystal structural stability, surface morphology and magnetic properties as a function of Cu2+ ion concentration were performed. The annealing treatment does not alter the crystal structure but increases the crystallinity of the samples. The cation occupancies of the prepared materials were estimated by using X-ray diffraction (XRD) data analysis. The morphological investigations of the samples were studied by using field emission scanning electron microscopy (FE-SEM) technique. The crystallographic analyses of all the compositions were systematically investigated by Fourier transform infrared spectroscopy (FTIR). The saturation magnetization (M–H plots) at room temperature with field 10kOe exhibits strong influence of Cu2+ ion content and annealing temperature. [Copyright &y& Elsevier]

Abstract: Annealing treatments were carried out at different temperatures (600–1200°C) for various holding times (2–10h) to evaluate the microstructural and mechanical properties changes of the AlN–SiC–TiB2 ceramic composites prepared by SHS–HIP. The experimental results show that the annealing treatment is beneficial to improve the mechanical properties. In the meantime, the desolution of SiC-rich solid solution and precipitation of fine TiB2 grains occurred. Due to the precipitation strengthening by the SiC-rich solid solution and the grain boundary strengthening by fine TiB2 particles, the improvement of the mechanical properties was obvious with higher annealing temperatures and longer holding times. The highest HRA, bending strength and fracture toughness were 94.1, 517.5MPa and 5.79MPam1/2, respectively, after the annealing treatment at 1200°C for 10h. [Copyright &y& Elsevier]

Abstract: In the framework of the ab initio atomic thermodynamics, the preliminary analysis of the oxygen defects in anatase TiO2 has been done by investigating the influence of the annealing treatment under representative conditions on three typical oxygen defects, that is, oxygen vacancy, oxygen adsorption and oxygen interstitial. Our results in this study agree well with the related experimental results. The molecular species of the adsorbed O2 is subject to the ratio of the number of the O2 to that of the vacancy, as well as to the initial orientation of O2 relative to the surface (101). Whatever the annealing condition is, the oxygen vacancy is easier to form at the surface than in the bulk indicating that the reduction reaction may firstly undertake at the surface during the annealing treatment, which is consistent with the phase transformation experiments. The molecular ion, peroxide species, caused by the interstitial oxygen has important contribution to the top of the valence band and lead to the reduction of the band gap. [Copyright &y& Elsevier]

Abstract: In the present paper, the energy dissipation characteristics of Fe–13Cr–2.5Mo damping alloy are studied using a mathematical model based on free-decaying vibration. The calculated results show that the DVE (dissipated vibration energy) value increases and gradually saturates with the increase of strain amplitude. The higher strain amplitude may drive more domain-walls to move, raising the DVE value in vibration. With nearly all domain-walls moving, the DVE value reaches a saturating state. The alloy annealed at 1173K has the highest DVE saturating value. Observation under optical microscope confirms that smaller domain size and sub-domains can make the alloy achieving a higher DVE value. [Copyright &y& Elsevier]

Abstract: Nanocrystalline CdS thin films were deposited on glass substrates by a new in situ chemical reaction synthesis using cadmium precursor solid films as reaction source and sodium sulfide based solutions as anionic reaction medium. The influence of the S:Cd molar concentrations in separate cationic and anionic precursor solutions and the deposition temperature on the crystallized structure, morphologies, chemical component and optical properties of the deposited CdS films was investigated by X-ray diffraction, field emission scanning electron microscope, energy dispersive X-ray analysis and UV–Vis spectra measurements. The results show that CdS thin films deposited by the in situ chemical reaction synthesis have wurtzite structure with (002) plane preferential orientation and this tendency gradually enhances with increase of S:Cd molar concentration ratio. The deposition rate was 80–100nm thickness per cycle in the range of deposition temperature from 20°C to 60°C. [Copyright &y& Elsevier]

Abstract: TiN thin films were deposited on Si wafers using an unbalanced magnetron (UBM) sputtering technique and then annealed in vacuum at temperatures ranging from 300 to 900°C. The microstructure and surface morphology of the thin films at various processing parameters were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The variation of the hardness and surface roughness over the course of annealing treatment temperature was investigated. Annealing treatment was found to induce changes in the microstructure, crystallinity, texture, grain size, hardness and roughness of TiN films. The hardness of TiN films decreased after heat treatment in the vacuum, while surface roughness increased significantly. Moreover, the maximum values of hardness and roughness could be observed in films annealed at 450°C in comparison to those at other annealing temperatures. [Copyright &y& Elsevier]

Al 0.3 CoCrFeNi is one of the widely studied high-entropy alloys (HEAs) due to the superior properties; however, its strength at room temperature is not satisfactory. The thermo-mechanical method was usually used to tune the mechanical property of materials. Here the as-cast Al 0.3 CoCrFeNi HEA was cold rolled and subsequently annealed for various times. The microstructural variation was characterized by X-ray diffraction, electron backscatter diffraction and transmission electron microscopy and the mechanical properties were estimated by microhardness and tension tests. It was found that the shorter annealing time led to a finer grain size and higher hardness. Besides, the yield strength of ~467 MPa, ultimate tensile strength of ~830 MPa and tensile elongation of ~48% were achieved in the thermo-mechanically processed alloy, which was comparable with or even a little higher than the previously reported data. The excellent combination of strength and ductility in this alloy was mainly ascribed to the combined action of residual dislocations, refined grains, and annealing and deformation twins in the dislocation motion. The calculated results of the contributions from different strengthening mechanisms to yield strength were well consistent with the experimental data. • Room-temperature property of HEA was tuned by thermo-mechanical method. • The balanced strength and ductility of Al 0.3 CoCrFeNi HEA were achieved. • Action of multiple microdefects in dislocation motion leads to improved property. • Yield strength was well predicted based on different strengthening contributions [ABSTRACT FROM AUTHOR]

Abstract: In our endeavor to improve the cyclic stability of the La–Mg–Ni–Co type alloys, the as-cast and annealed La0.7Mg0.3Ni2.45Co0.75Mn0.1Al0.2 hydrogen storage alloys were prepared and the effects of annealing at 1173, 1273 and 1373K for 8h on the crystal structures and the overall electrochemical properties of the alloys are reported in this paper. XRD and Rietveld analyses have revealed that the major phases of all the alloys are the (La,Mg)Ni3 phase and the LaNi5 phase. Both the lattice parameters and cell volumes of the (La,Mg)Ni3 phase and the LaNi5 phase increase with increasing annealing temperature, but the phase abundance of these two phases varies differently. It is found that the discharge capacity and the cycle life of the alloys are improved after annealing treatment owing to the variable phase abundance and composition homogenization, respectively. However, high rate dischargeability (HRD), electrochemical impedance spectra (EIS), linear polarization, anode polarization and potential-step studies indicate that the electrochemical kinetics of the alloy electrodes is deteriorated after annealing treatment. This phenomenon can be ascribed to that the composition homogenization and the suppression of the pulverization due to decreasing of the crystal lattice strain and defect after annealing treatment, which increases the charge-transfer resistance of the alloy electrodes and also reduces the rate of the diffusion of hydrogen from the interior of the bulk to the surface. [Copyright &y& Elsevier]

• A high strength and ductility AZT522 alloy was developed to compete with AZ91 alloy. • The AZT522 alloy had much finer as-cast microstructure than AZ91 alloy. • The AZT522 alloy exhibited superior rolling formability to the AZ91 alloy. • The annealed AZT522 alloy showed higher strength and ductility than AZ91 alloy. A novel Mg-5.34Al-2.23Zn-1.73Sn (wt%, AZT522 for short) alloy with high strength-ductility synergy was designed and fabricated via simple hot rolling and annealing treatment to compete with the commonly used Mg-9Al-1Zn-0.2Mn (wt%, AZ91) alloy. Different from the coarse microstructure of the as-cast AZ91 alloy, the as-cast AZT522 alloy has much finer microstructure, which consists of finer dendrites and smaller second phase particles. Hot rolling was carried out on the solution-treated alloys to effectively refine the microstructure and improve the mechanical properties. The results suggest that the AZT522 alloy shows better rolling formability. Then, the hot-rolled AZT522 alloy was annealed at the optimized parameter, i.e., 225 °C/1.5 h, leading to uniform fine grains with an average size of ~2.3 µm and numerous near-spherical precipitates (Mg 17 Al 12 and Mg 2 Sn) with a mean diameter of ~90 nm. Benefiting from the fine annealing microstructure, the novel AZT522 alloy finally exhibited high tensile properties at room temperature, i.e., ultimate tensile strength (UTS) of ~343 MPa, yield strength (YS) ~271 MPa, and elongation to failure (δ f) ~16%, which is a much better combination of strength and ductility than the annealed AZ91 alloy. This novel AZT522 alloy may provide a new insight to develop commercial high strength and ductility Mg alloys. [ABSTRACT FROM AUTHOR]

Using a dual aluminum zinc oxide (AZO) target and tin dioxide (SnO 2) target, 200-nm-thick aluminum-tin-zinc-oxide (ATZO) films were deposited onto quartz substrates by a radio frequency magnetron cosputtering system. After measuring X-ray diffraction patterns, carrier concentration, carrier mobility, room-temperature photoluminescence spectra, and ultraviolet–visible–near infrared spectra of the ATZO films without and with thermal annealing treatment in an oxygen ambience for 10 min at various temperatures, the annealing effects were demonstrated. Correlations among crystalline structures, electrical properties, optical properties, and annealing temperatures were observed. As the annealing temperature increased from 200 °C to 300 °C, the atoms of ATZO films gained more kinetic energy and more surface mobility to occupy stable positions. However, by further increasing the annealing temperature to 400 °C, the bonds in ATZO films became broken rather than enabling the atoms to remain in their corresponding stable positions. Consequently, the best properties were obtained for ATZO films annealed at 300 °C. • Aluminum-tin-zinc-oxide (ATZO) film was deposited by magnetron cosputtering system. • Individual at% of Al, Sn, Zn, and O of ATZO film was 2.31, 2.69, 43.95, and 51.05%. • Better crystallinity and grain size of ATZO film annealed at 300 °C were obtained. • ATZO films annealed at 300 °C had the lowest oxygen vacancies and intrinsic defects. [ABSTRACT FROM AUTHOR]

Mild doping of nitrogen (N) in TiO 2 followed by an optimized aerial annealing treatment of CdS quantum dot (QD) sensitized photoanode resulted in efficient electron transfer and low recombination rates for the corresponding quantum dot solar cell (QDSC). Nitrogen doping passivates the surface defects in TiO 2 , reduces the density of recombination centers, and promotes electron injection into the current collector. N-doping also modifies the electronic band structure of TiO 2 and reduces the band gap from 3.17 to 2.91 eV. Therefore in the QDSC with the N-TiO 2 /CdS photoanode, both N-TiO 2 and CdS, undergo charge separation upon illumination thereby producing a higher photocurrent compared to the undoped-TiO 2 /CdS based QDSC. N-doping also increased the redox activity of TiO 2 , allowing facile ion and electron transport across its cross-section which is advantageous for solar cell performance. Optimal annealing temperature of 150 °C for the N-TiO 2 /CdS or TiO 2 /CdS photoanode restricted the back electron movement effectively, and imparted a significantly enhanced power conversion efficiency (PCE) to the N-TiO 2 /CdS@150 °C/polysulfide gel/C-fabric- solar cell, greater by 55% compared to its unannealed counterpart. Lowered average excited electron lifetime, increased-incident photon-to-current conversion efficiency, recombination resistance and photovoltage decay response time, confirm the ability of the annealed photoanodes to undergo enhanced charge separation contrasting with the unannealed photoanode. This first time study relies on two simple approaches of nitrogen doping and annealing treatment to achieve considerably improved photovoltaic parameters, and opens up realistic possibilities for commercialization of QDSCs. Image 1 • Nitrogen (N) doping of TiO 2 passivates the surface defects. • N-doped TiO 2 produces additional photocurrent, by undergoing charge-separation. • N-doping enhances the redox activity of the oxide, promotes electron/ion transport. • Annealing treatment at 150 °C enables facile charge transfer at the quantum dot/oxide interface. • Efficiency of the solar cell: N-TiO 2 /CdS@150 °C/polysulfide gel/C-fabric is 4.58%. [ABSTRACT FROM AUTHOR]

In order to obtain the carbon nanodots dispersed in the solid state films, carbon-rich amorphous hydrogenated silicon carbide (a-SiC x :H) films were prepared by PECVD method and were subsequently annealed at Argon protective environment for 30 min with different annealing temperatures (T a). Raman spectra show that the amorphous carbon nanodots were formed within the a-SiC x :H films as T a is equal to and higher than 600 °C. Meanwhile, the decomposition and transformation from sp3 C to sp2 C of the carbon nanodots can be inferred by the Raman spectra with increasing T a. XPS analysis suggest that the near-surface oxidation of the films become strong as T a > 600 °C which can be contributed to the chemical bond reconstruction and the formation of carbon nanodots within the films. The decrease of the optical band gap derived from the measured absorption spectra of the films can be attributed to the formation and graphitization of the carbon nanodots within the a-SiC x :H films. HRTEM measurements indicate that the enhancement of the areal density and the size reduction of the carbon nanodots take place within the a-SiC x :H films with increasing T a. However, the dispersion of the carbon nanodots embedded in the a-SiC x :H films is still very bad compared with that of the CQDs dispersed in chemical solvents. PL measurements show that the PL signals may originate from the related defect states rather than the carbon nanodots within the a-SiC x :H films. • The carbon nanodots have better thermal stability compared to a-C: H films. • The near-surface of a-SiC:H films with carbon nanodots can be easily oxidized. • The graphitization of carbon nanodots increases with annealing temperature. • The carbon nanodots embedded in the films have strong tendency to aggregation. • The aggregation tendency of carbon nanodots was weakened by annealing treatments. [ABSTRACT FROM AUTHOR]

This study tried to enhance simultaneously the surface micro-hardness as well as corrosion resistance of Ti by preparation of in-situ Al/Ti 5 Si 3 –Al 3 Ti composite using TIG process and 4043 Al filler alloy. The alloyed layers were characterized using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). ASTM E384-HV and X-ray diffraction via ψ analysis were employed for determination of micro-hardness of prepared samples, and residual stresses at the interface of prepared coatings. To study the corrosion behavior of the final products used from NaCl 3.5 wt% electrolyte by potentiostat analysis. Surface coating was carried out by consideration of dilution ratio and passes number as operational variables. Results showed that, by increasing of pass number and filler injection rate, the thickness of Ti 5 Si 3 layer at the interface gradually increased. In addition, Al 3 Ti phase formed far from the interface. In these conditions, the corrosion resistance and micro-hardness of prepared coatings were enhanced through the cladding. Analysis of residual stresses on the prepared coating at optimum condition confirmed the evolution of tensile residual stresses equal to 290 ± 40 MPa at the center line of fusion zone. The prepared sample with the highest surface micro-hardness as well as corrosion resistance was selected as optimum condition for investigating the effect of time (from 1 to 20 h s) and temperature (550–600 °C) through annealing process. Annealing treatment for 10 h s at 600 °C, not only enhanced the amount of Ti 5 Si 3 –Al 3 Ti phases and provided the possibility of the formation of adhesive and uniform Ti 5 Si 3 layer at the interface of the clad/substrate but also raised the micro-hardness and corrosion resistance of the prepared coatings and determined as optimum condition. • Coating of Ti substrate with Al/Ti 5 Si 3 –Al 3 Ti phases using TIG welding procedure. • Investigation the hardness as well as corrosion resistance of prepared samples. • Studying the effect of annealing treatment on the hardness and corrosion behavior. • Analysis of residual stresses on prepared coating by nondestructive test. [ABSTRACT FROM AUTHOR]

We present a comparative study of synthesis of M-type strontium hexaferrite from strontium and iron single oxides mechanically activated by high-energy ball milling for 5 h, and assisted by two different methods: (a) conventional heat treatment and (b) Spark Plasma Sintering (SPS), both at relative low temperatures ( ⩽ 900 °C). Although it was found that both methods promoted the complete structural transformation of precursors to Sr-hexaferrite phase (S.G. Pmc21 ) for temperatures above 700 °C, higher saturation magnetization was found for SPS samples. X-ray diffraction analysis revealed that the structural transformation undergoes formation of an intermediate metastable structure (Fe 2 Sr 2 O 5 ) in both methods, but with slight different kinetics. Maximum specific magnetization of 67 emu/g at 18 kOe and coercivity of 3.7 kOe were recorded from powder mixtures milled for 5 h, which were subsequently SPS-ed at 700 °C. By contrast, although magnetization values for the same milled samples after being annealed at 700 °C slightly decreased, it leads to a significant increase in the coercive field reaching 5.4 kOe. These results are explained on the basis of factors such as the complete formation of hexaferrite and the attained density of consolidated powders, in addition to particle and grain sizes also reported. [ABSTRACT FROM AUTHOR]