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Abstract: Ni–P alloy with overall composition of 7.0wt.% phosphorus was fabricated via electroless plating on substrate of aluminum foil. The effects of this Ni–P master alloy on the modification and the processing for hypereutectic Al–20wt.%Si alloy have been investigated. Primary silicon of hypereutectic alloy can be refined sufficiently by adding this Ni–P master alloy with total amount of 0.008wt.% phosphorus above 800°C. There is no phosphorus burning loss during fabrication of hypereutectic Al–Si alloy modifier by electroless deposition, and environment pollution is reduced. Refinement of primary silicon can be achieved with less addition and a shorter time of processing by use of this electroless deposited Ni–P master alloy as modifier. [Copyright &y& Elsevier]

In this paper, we reported the effects of the order of plasma treatment and high temperature annealing on solution-processed amorphous indium magnesium zinc oxide (a-IMZO, In:Ga:Zn = 3:1:1) thin film transistors (TFTs). Specifically, we utilized two different processes to fabricate TFTs. In one process, the active layers were plasma-treated (PT, 10 W, 10min) before high temperature thermal annealing (TA, 400 °C), and in another process, the active layers were plasma-treated after high temperature annealing. The former achieves lower off-current (5.83 × 10−12 A) and larger on/off current ratio (2.2 × 107), because the oxygen-related ions in the N 2 O plasma treatment can passivate the surface of the active layer and reduce the residual organic groups. However, introducing of O2+ and O2− ions leads to an increase in interface defects. The latter sample reaches a mobility 1.97 cm2/V·s, as the generated nanopores during high temperature annealing provide path for more atomic oxygen to infiltrate the film during PT and the oxygen vacancies are reduced. However, the on-current drops sharply with plasma treatment power for the increase of oxidation depth. In addition, all the PT samples show small hysteresis and improved stabilities. Our study suggests that moderate plasma treatment can be adopted to improve the a-IMZO TFT device performances. • PTbTA sample achieves lower off-current and larger on/off current ratio. • I on of PTaTA sample increases significantly and achieves higher mobility. • All the samples indicate an amorphous structure. • All the PT samples show small hysteresis and improved stabilities. [ABSTRACT FROM AUTHOR]

A series of Dy 3+ ions doped bismuth phosphate (BiPO 4 ) phosphors have been successfully synthesized via a facile and simple hydrothermal method by tuning the molar ratio of PO 4 3− /[Bi 3+ +Dy 3+ ] and the Dy 3+ ions concentration, and the structure, morphology and luminescence properties of the phosphors were characterized by X-ray diffraction (XRD), field-emission scanning electronic microscopy (FE-SEM) and photoluminescence (PL) spectra. The XRD patterns indicate that the BiPO 4 :Dy 3+ sample with low temperature monoclinic phase (LTMP) grows preferentially along the (120) crystalline plane at the excessive PO 4 3− introduced. From the FE-SEM images, the morphology of BiPO 4 :Dy 3+ powder varying from irregular polyhedron-like to rod-like is observed with increasing the molar ratio of PO 4 3− /[Bi 3+ +Dy 3+ ]. More importantly, the emission intensity of BiPO 4 :Dy 3+ phosphor enhances dramatically with the excessive PO 4 3− ions in the precursor. Therefore, the luminescence properties of the BiPO 4 :Dy 3+ phosphors can be improved significantly through controlling the molar ratio of PO 4 3− /[Bi 3+ +Dy 3+ ] in the precursor mixture, which may be a novel way to explore new luminescent materials. [ABSTRACT FROM AUTHOR]

The spheroidization behavior of γ′ phase and dynamic recrystallization (DRX) mechanisms of a novel HIPed powder metallurgy (P/M) superalloy deformed at high temperatures (1080−1170 ℃) and different strain rates (1–0.001 s−1) are investigated. The results show that the spheroidization behavior of γ' phase and DRX mechanisms are greatly influenced by deformation condition. The coarse γ′ Ⅰ phase promotes the DRX process, while the fine spherical γ' Ⅲ phase results in the formation of sub-grain boundaries. Thus, the grains are refined. During hot deformation, some coarse γ′ Ⅰ and γ′ ⅠⅠ phases transform into the fine spherical γ' Ⅲ phases, while some initial γ' Ⅲ phases gradually diminish. Besides, the spheroidization rates of γ′ Ⅰ , γ′ Ⅱ and γ' Ⅲ phases increase with the increase of strain rate. The low DRX volume fraction and refined grains with the average size of 2.27 µm are obtained at 1110 ℃/1 s−1. It is attributed to the fact that the DRX nucleation is obviously enhanced and the pinning effects of spherical γ′ Ⅲ phases on dislocations accelerate the formation of sub-grains. In addition, the discontinuous DRX is the main DRX mechanism of this novel P/M superalloy. • Spheroidization and DRX mechanisms of a novel HIPed P/M superalloy during hot deformation is studied. • The coarse γ′ Ⅰ phase promotes the DRX by inducing the dislocation accumulation. • The fine spherical γ' Ⅲ phases result in the formation of sub-grain boundaries and the grains are refined. • Some coarse γ′ Ⅰ and γ′ ⅠⅠ phases transform into the fine spherical γ' Ⅲ phases during hot deformation. • The discontinuous DRX is the main DRX mechanism of this novel P/M superalloy. [ABSTRACT FROM AUTHOR]

• (PEA) 2 PbBr 4 with improved properties were obtained via CsBr additive; • Enhanced surface morphology and optical properties of modified (PEA) 2 PbBr 4 ; • Responsivity for 2D perovskite photodetector based on sol-gel method is 0.67 AW−1; • Rise time and decay time are about 0.28 s and 0.21 s; • Spectral wavelength selectivity of (PEA) 2 PbBr 4 based photodetector was accomplished. Wavelength-dependent responsivity and detectivity of cesium halides additive photodetectors based on two-dimensional perovskite: (C 8 H 9 NH 3) 2 PbBr 4 under 10 V bias. [Display omitted] Considering of cost-effective and simple assembly principle of organic-inorganic halide perovskite (OIHP), producing perovskites into polycrystalline thin films from precursor solution has proved to be appealing. In this paper, (C 8 H 9 NH 3) 2 PbBr 4 was fabricated based on C 8 H 9 NH 3 Br (PEABr) and PbBr 2 according to compositions in the vicinity of (PEA) 2 PbI 4 , and the two-dimensionally (2D) perovskite was obtained which entitled with superior photoelectric performance, excellent solution processability and flexible substrates compatibility. And hydrophobic nature of spacer cation of aromatic alkylammonium or a large aliphatic both with the highly consistent orientation of 2D perovskites are beneficial for reducing the grain boundaries density. Meanwhile, optimized (PEA) 2 PbBr 4 were obtained via CsBr additive. Systematic material characterizations manifested enhanced surface morphology, photoluminescence efficiency and carrier lifetime of the CsBr modified (PEA) 2 PbBr 4. Then related (PEA) 2 PbBr 4 based photodetectors exhibited a good responsivity of 0.67 AW−1 when detectivity approached 5.2 × 1011 Jones, and a large on/off ratio about 500 was obtained. Meanwhile, the devices possessed noticeable stability during the optical switch tests with the rise time and decay time about 0.28 s and 0.21 s for CsBr dopped devices illuminated by 385 nm under 10 V bias. More importantly, spectral wavelength selectivity of CsBr based photodetector indicated the potential utilization in ultraviolet detecting when a wide bandgap of 3.018 eV was obtained. [ABSTRACT FROM AUTHOR]

Abstract: Microstructure characterization is important for controlling the quality of laser welding. In the present work, a detailed microstructure characterization by transmission electron microscopy was carried out on the laser welding cast Ni-based superalloy K418 turbo disk and alloy steel 42CrMo shaft and an unambiguous identification of phases in the weldment was accomplished. It was found that there are γ-FeCrNiC austenite solid solution dendrites as the matrix, (Nb, Ti) C type MC carbides, fine and dispersed Ni3 Al γ′ phase as well as Laves particles in the interdendritic region of the seam zone. A brief discussion was given for their existence based on both kinetic and thermodynamic principles. [Copyright &y& Elsevier]

Abstract: Exploratory experiments of laser welding cast Ni-based superalloy K418 turbo disk and alloy steel 42CrMo shaft were conducted. Microstructure of the welded seam was characterized by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive spectrometer (EDS). Mechanical properties of the welded seam were evaluated by microhardness and tensile strength testing. The corresponding mechanisms were discussed in detail. Results showed that the laser-welded seam had non-equilibrium solidified microstructures consisting of FeCr0.29Ni0.16C0.06 austenite solid solution dendrites as the dominant and some fine and dispersed Ni3Al γ′ phase and Laves particles as well as little amount of MC short stick or particle-like carbides distributed in the interdendritic regions. The average microhardness of the welded seam was relatively uniform and lower than that of the base metal due to partial dissolution and suppression of the strengthening phase γ′ to some extent. About 88.5% tensile strength of the base metal was achieved in the welded joint because of a non-full penetration welding and the fracture mechanism was a mixture of ductility and brittleness. The existence of some Laves particles in the welded seam also facilitated the initiation and propagation of the microcracks and microvoids and hence, the detrimental effects of the tensile strength of the welded joint. The present results stimulate further investigation on this field. [Copyright &y& Elsevier]

• ZnO nanorod arrays were prepared using hydrothermal assisted with PEI. • The photodetectors based on PEI-ZnO show a quick response time (~4 s) and high responsivity (~56 A/W). • The flexible devices display reliable stability and robustness under bending tests. • Raman and XPS spectra reveal the defect mechanisms on improved performance. [Display omitted] Investigations on the high-performance flexible ultraviolet photodetectors have been becoming one of the interesting research focuses in recent years. ZnO is considered as suitable material for ultraviolet photodetection due to its wide bandgap (~3.37 eV). In this work, ZnO nanorod arrays were prepared using the hydrothermal method at the temperature of 70 ℃ on flexible substrates. Polyethyleneimine (PEI) was added into hydrothermal solution as the growth additive to achieve the performance improvement of the ZnO nanorod arrays ultraviolet photodetector. SEM, XRD, absorption spectroscopy, Raman spectroscopy and XPS were employed to characterize the morphology, crystallinity, optical properties and chemical composition. The introduction of PEI adjusts the growth process of ZnO nanorod arrays and affects the distribution of defect states, which brings out the improvement of the optoelectronic performance of ZnO nanorod arrays ultraviolet photodetectors. Compared with pure ZnO, the higher photo to dark current ratio and responsivity, and quicker time response speed are demonstrated in the PEI-assisted ZnO nanorod arrays photodetectors. And more photoresponse parameters are also discussed and compared. Furthermore, the photodetectors also display outstanding mechanical flexibility and robustness under multiple bending cycle tests. Our work presents a potential approach for improving the optoelectronic performance of simple-operated flexible ultraviolet photodetectors. [ABSTRACT FROM AUTHOR]

Highlights: [•] A core-shell cathode material is redesigned without composition change. [•] Core-shell material displayed a superior cyclability and thermal stability. [ABSTRACT FROM AUTHOR]

Highlights: [•] A surface-to-surface contact between graphene and SnO2 nanoplates is synthesized for the first time. [•] The synthesized method is easier to implement without template. [•] The as-synthesized materials exhibit high-performance supercapacitor than pure SnO2 and other SnO2/graphene nanocomposites. [ABSTRACT FROM AUTHOR]

Approachable graphdiyne (GDY), characterized by discrepancy hybridized carbon atoms of inhomogeneous π-bonding and carbon 2pz overlapping of orbitals, reveals versatility applications. Previously, interfaces high density between different structure materials induce the high response of photodetector, but the ratio of photocurrent to dark current is restricted for either limited materials properties or lattice mismatch when junctions formed. In this work, titania (TiO 2) nanocrystals with a rational phase of anatase are encapsulated on GDY particles, further, the TiO 2 :GDY nanocomposites are synthesized. High specific surface area GDY, as a proper sustaining material optimizes the characters of TiO 2 nanocrystals. Then TiO 2 :GDY nanocomposites cooperate with Mg0.3Zn0.7O (MZO) are mean to fabricate lateral bilayer ultraviolet photodetector. Because of the formed heterojunction between TiO 2 :GDY nanocomposites and MZO, the ultraviolet photodetector is highly sensitive to deep ultraviolet light, when optical band gap of MZO is as high as 3.8 eV. The responsivity of TiO 2 :GDY/MZO bilayer photodetector is also increased by more than one order of magnitude to 76 mA W−1 compares to the MZO device without TiO 2 :GDY nanocomposites while the photocurrent rejection is about three orders of magnitude from 254 nm to 365 nm. Meanwhile, signal-to-noise ratio is calculated as high as 1.5 × 105 in this work. Image 1 • Titania with anatase phase are encapsulated on graphdiyne particles. • The sintering between adjoining Titania nanocrystals is restrained by graphdiyne. • The photocurrent rejection is about three orders of magnitude from 254 nm to 365 nm. • The high signal-to-noise ratio of bilayer photodetector is calculated as 1.5 × 105. [ABSTRACT FROM AUTHOR]

Abstract: A process of laser cladding Ni–Cr–C–CaF2 mixed powders to form a multifunctional composite coating on γ-TiAl substrate was carried out. The microstructure of the coating was examined using XRD, SEM and EDS. The coating has a unique microstructure consisting of primary dendrite or short-stick TiC and block Al4C3 carbides reinforcement as well as fine isolated spherical CaF2 solid lubrication particles uniformly dispersed in the NiCrAlTi (γ) matrix. The average microhardness of the composite coatings is approximately HV 650 and it is 2-factor greater than that of the TiAl substrate. [Copyright &y& Elsevier]