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Those peritectic alloys with large positive mixing enthalpy usually display metastable liquid phase separation. Here, the solidification kinetics for a model Fe 50 Cu 50 alloy in broad cooling rate R c range was predicted by phase-field simulations and confirmed by drop tube experiments. Near-equilibrium peritectic solidification occurs in small R c regime below 5.62×10 2 K s −1 . As R c rises beyond 7.76×10 2 K s −1 , metastable phase separation takes place and results in the formation of a dispersed structure. Afterwards, multilayer core-shell structures appear, and the layer-number varies from two-layer to six-layer with further increasing R c . Once R c exceeds 3.64×10 5 K s −1 , a dispersed structure once again forms because the core-shell dynamic condition is not satisfied. Non-equilibrium peritectic solidification is induced if R c is greater than 5.85×10 5 K s −1 . [ABSTRACT FROM AUTHOR]

Supersaturated Ni–Sn solid solutions with Sn solubility up to 9.2 at% have been obtained through rapid solidification in the undercooling range of 220–280 K. The lattice properties including the lattice constant, microscopic lattice distortion, thermal expansion and linear expansion coefficient are investigated experimentally and theoretically. The lattice constants increase about 0.01 Å per 1 at% Sn in linear way. The lattice distortions are mainly confined to the first nearest-neighbor atoms with the values of (3.5±0.3)%, and are less than 1% for farther atoms. The thermal expansions vary only a little with Sn content and exhibit obvious increase for the as-cast solid solutions above 1150 K due to the phase transformation of Ni 3 Sn compound, whereas they increase smoothly with temperature for the annealed supersaturated samples. [ABSTRACT FROM AUTHOR]

Acidic oxidation method has been massively reported as an effective method to functionalize the surface of carbon nanotubes (CNTs). However, these corrosive acids are extremely dangerous. In this paper, CNTs are firstly oxidized in alkaline solution consisting of sodium hypochlorite and potassium permanganate instead of strong acids, and subsequently the mixture is neutralized by hydrogen peroxide solution to complete the secondary oxidation in the process. Experimental results indicate that more defects in CNTs are more likely to form and functional groups are successfully grafted onto CNTs after oxidation. Moreover, zeta potential result shows that the treated CNTs with negative groups have superior suspension stability. Furthermore, the treated CNTs, length of which is shorter than that of the pristine ones, are separated from each other. Meanwhile, the treated CNTs can remain as a colloidal (well dispersed) solution for 30days. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, YVO4:Yb3+,Er3+ microspheres have been successfully prepared through a facile hydrothermal method assisted with disodium ethylenediaminetetraacetic acid and citric acid. X-ray diffraction, field emission scanning electron microscopy, energy disperse X-ray spectroscopy, high resolution transmission electron microscopy, and photoluminescence spectra were used to characterize the samples. The results reveal that the as-prepared YVO4:Yb3+,Er3+ samples are well-crystallized and spherical in shape. Moreover, the microspheres with diameters of 6–8μm are assembled by numerous submicron cuboids. Under the excitation of a 980nm laser diode, the samples show the characteristic emissions of Er3+ and the green emissions at 525nm of 2H11/2→4I15/2 are dominantly strong. [Copyright &y& Elsevier]

• A novel nanostructured Fe 39 Cr 39 Ni 14 C 8 eutectic high entropy alloy was developed. • The rapid solidification alloy exhibits a typical fully lamellar FCC1/FCC2 eutectic structure. • FCC1 phase has a unique cube-cube coherent relationship with FCC2 phase. • Its high hardness and high yield strength originate mainly from the phase interface strengthening. A novel nanostructured Fe 39 Cr 39 Ni 14 C 8 eutectic high entropy alloy (EHEA) was developed by rapid solidification. Detailed characterization reveals that the rapidly solidified Fe 39 Cr 39 Ni 14 C 8 EHEA shows a nano-lamellar structure consisting of alternative FCC1 (∼120 nm in width) and FCC2 (∼80 nm) phases with a coherent relationship and possesses a high hardness of 463HV (∼4.5 GPa) and a high yield strength of 1.45GPa. They are mainly attributed to the unique ultrafine eutectic structure. This finding would shed new light on the development of FCC1/FCC2-nanostructured EHEAs with excellent mechanical properties. [ABSTRACT FROM AUTHOR]