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Nano-sized lanthanum hexaboride (LaB6)@ titanium dioxide (TiO2) particles with a core–shell structure has been successfully synthesized via a simple sol–gel method. LaB6@TiO2 particles were used as filler in polyvinyl butyral (PVB) matrix and performance of the TiO2 shell was evaluated. The core–shell nanoparticles were characterized for morphology and structure properties. X-ray diffraction and transmission electron microscope testing results confirm the formation of LaB6–TiO2 core–shell structure. In composite film, LaB6 improved the thermo-decomposing temperature of PVB matrix from 369.2 to 372.8°C, while the same amount of LaB6@TiO2 further increased the temperature to 381.0°C. In addition, TiO2 shell redshifted the maximum transmittance of the film from 605 to 669 nm in the visible region. In the near infrared region, its absorption peak shifted from 1,466 to 1,476 nm. This result will be helpful for the development of transparent and thermal insulating materials.

Multiferroic composites with ferromagnetic and ferroelectric properties can be used in nanobiomedicine and multifunctional drug load owing to their strong magnetoelectric performance at room temperature. In this study, cobalt ferrite (CFO) and barium titanate (BTO) nanocomposites are synthesized by chemical co-precipitation method, the fraction of CFO with respect to the BTO is 20, 40, and 60 wt% (hereafter abbreviation as C20, C40, and C60). In this way, CFO as the growth site of BTO grains, forms a structure that BTO grains coated CFO grains. With the addition of CFO, the crystalline size of BTO in nanocomposites become smaller than pure BTO, particles size of nanocomposites is between 48 and 60 nm, lower than pure BTO. Smaller particle size of nanocomposites lead to higher dielectric constant in nanocomposites. The magnetization (M) versus field (H) loops reveal the ferromagnetic nature of CFO–BTO nanocomposites. All nanocomposite samples present outstanding ME effect with high αME value of exceeding 41 mV Oe−1 all samples, reaching 44.13 mV Oe−1 of C20. [ABSTRACT FROM AUTHOR]

In order to provide a sufficient theoretical basis for the fatigue‐resistant design of the aircraft wheels, strain‐controlled low‐cycle fatigue (LCF) tests were carried out on specimens machined in the extrusion direction (ED) and transverse direction (TD) of die‐forged 2014 aluminum alloy wheels. Although the TD specimens have lower tensile strength and yield strength, the fatigue test results show that the TD specimens have superior fatigue life compared with the ED specimens at total strain amplitudes of 0.5–0.8%. This is predominantly caused by the coarse Al12(MnSi)2(FeCu) intermetallic particles close to the surface layer, which results in a relatively short crack initiation stage for the ED specimens. In contrast, TD specimens with finer and more uniform recrystallized grains exhibit more excellent resistance to fatigue crack initiation (FCI) and propagation (FCP). Moreover, the fatigue life of alloys could be accurately predicted via a Manson–Coffin–Basquin (MCB) model based on total strain. Highlights: A new die forging method was used to fabricate the aircraft wheel.Fatigue characteristics and fracture behavior of aircraft wheels were explored.The accuracy of different fatigue life prediction models was evaluated.Coarse Al12(MnSi)2(FeCu) intermetallic particles affected fatigue crack initiation. [ABSTRACT FROM AUTHOR]

Red and far‐red spectral components are the basics for color rendering improvement of illumination devices and growth regulation of plants, respectively. Establishing a feasible design principle in solid state materials for the red/far‐red phosphors is significant but challenging. Realizing metal to metal charge transfer (MMCT) in Bi3+‐doped phosphors is a new strategy to target the red/far‐red luminescence. As a proof of concept, the MMCT state involving the ground state of Bi3+ ion and the excited state of host (Nb/Ta)5+ cations in Na2Ca3(Nb, Ta)2O9:Bi3+ induces efficient and tunable yellow/far‐red luminescence (peaking at 597–667 nm). Moreover, benefited from the appropriate distance between Bi3+ and (Nb/Ta)5+ ions, Na2Ca3(Nb, Ta)2O9:Bi3+ possess intense absorption in near‐ultraviolet region and no absorption in visible region. The plant growth light with the blending of Na2Ca3Nb2O9:Bi3+ far‐red phosphor and BAM:Eu2+ blue phosphor yields broadband electroluminescence covering almost the entire absorption spectra of chlorophyll and phytochrome, which is superior to the Cr3+‐ and Mn4+‐based light‐emitting diode (LED) devices. The white‐LED device by employing Na2Ca3Ta2O9:Bi3+ yellow phosphor as the essential component yields full‐spectrum warm white light with high color indexes. [ABSTRACT FROM AUTHOR]

In this work, CoFe2O4/CoFe particles were prepared by two steps methods of ethylene glycol solvothermal and hydrogen reduction. The structure and morphology of the samples were characterized by X-ray diffraction and field-emission scanning electron microscopy. The samples were mixed with paraffin wax at a mass ratio of 3:1 to prepare rings with an inner diameter of 3.04 mm and an outer of 7 mm, and its electromagnetic parameters were measured by a network vector analyzer. The results show that the dielectric loss and magnetic loss of the composites can be improved after high temperature hydrogen reduction. The optimal reflection loss of −52.14 dB can be achieved at 12.34 GHz in a thickness of only 1.7 mm, when CoFe2O4 was annealed at 500°C for three hours, and the obtained particles can reach less than −20 dB in all C, X, and Ku bands. In all the samples annealing under 500–700°C, the maximum absorption bandwidth over 5.0 GHz can be observed. By comparing the impedance matching properties of CoFe2O4 precursor and CoFe2O4/CoFe composites, it is found that the tunability of the electromagnetic property in composite structure contributes to the excellent electromagnetic wave absorbing performances. [ABSTRACT FROM AUTHOR]

The microstructure in different regions of 2A14 aluminum alloy wheel and their effects on both mechanical properties and corrosion properties were studied by electron backscatter diffraction (EBSD), field emission scanning electron microscope ( SEM), transmission electron microscope ( TEM), room temperature tensile test, immersion test and electrochemical polarization. The results show that the grains size of the center and 1/4 layer of the 2A14 aluminum alloy wheel are 113 and 54 µm respectively, and the recrystallization fractions are 16% and 36%. The intermetallics and the aging precipitates in the 1/4 layer are larger than those of the center and the number density of the two aging precipitates (ϑ' and Q phase) is about twice that of the center. The lower quenching cooling rate of the center of the 2A14 aluminum alloy wheel reduces the number of precipitates and the dislocation resistance. Therefore it is mechanical properties are worse than 1/4 layer. The number of intergranular corrosion sites and the depth of intergranular corrosion in the center are smaller than those in the 1/4 layer due to the lower intermetallics content [ABSTRACT FROM AUTHOR]