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The superimposition of multiple factors has presented a formidable challenge in establishing the salient features of grain size distribution for the large-scaled complex titanium alloy casting (LCTAC). In this study, an anatomical analysis within a LCTAC was conducted to acquire microstructure and mechanical properties distribution characteristics in typical zones. Through the progressive convergence, variable selection, and data dimensionality reduction techniques employed in the LASSO regression of microstructure characteristics and mechanical properties, the efficacious establishment of microstructural attributes has been accomplished. Consequently, a quantitative relationship between the microstructure and properties of the LCTAC has been formulated, predicated on the characteristics of grain size distribution. The findings unequivocally illustrate that the order of convergence for the microstructural parameters affecting the tensile strength of the LCTAC is as follows: expectation of grain size, mean grain size, full width at half maximum of grain size distribution, and the 99th percentile grain size. There exists a linear negative correlation between the 99th percentile grain size and tensile strength for the LCTAC, with a root mean square error in tensile strength prediction of less than 2%. • An anatomical analysis is performed within the large-scaled complex titanium alloy casting (LCTAC). • LASSO regression is introduced to augment the precision of quality assessment and control for the LCTAC. • A novel microstructural determinant influencing the tensile strength of the LCTAC is discovered. • A quantitative correlation between grain size distribution and mechanical properties within the LCTAC is established. [ABSTRACT FROM AUTHOR]

Mg 3 (VO 4) 2 (MVO) microwave dielectric ceramics were fabricated by a conventional solid-state sintering method at different sintering temperatures (T s) between 1000 °C and 1100 °C. The effects of T s on the phase evolution, the crystal structures, the dielectric responses, and the lattice vibrational characteristics of MVO were investigated. XRD patterns after Rietveld refinement were applied to analyze the phase evolution and the crystal structures of the samples, which shows the orthorhombic structure with the space group of Cmca for the MVO ceramics. Micrograph from scanning electron microscopy shows a uniform and dense crystal structure with the highest bulk density for the MVO sample sintered at 1050 °C. Raman scattering spectroscopy and infrared reflectance spectroscopy were used to dissect the lattice vibrational characteristics of the MVO ceramics. There are two types of vibrational modes of the MVO samples, i.e. , the external modes caused by the deformation of [VO 4 ]3- and the rotational and translational vibrations of the lattices, the internal modes attributed to the asymmetric stretching vibrations of V-O bonds. The intrinsic dielectric properties were determined by fitting the data with a four-parameter semi-quantum (FPSQ) model. Modes 1, 2, and 4, associated with the external modes, have the greatest contribution coefficient of 65.58% to the dielectric constant, and Mode 1 has the greatest contribution coefficient of 51.40% to the dielectric loss. The structure-property relationships were semi-quantitatively mathematically established according to the Raman modes. The MVO sample sintered at 1050 °C has the best dielectric properties of ε r = 9.59 and Q × f = 41,193 GHz (f = 13.69 GHz). • Mg 3 (VO 4) 2 microwave dielectric ceramics of crystal structures, dielectric properties, and phonon characteristics were studied. • The lattice vibrational characteristics were analyzed utilizing Raman and infrared reflection spectroscopy. • The physical mechanism of the dielectric response was clarified. • Relationships of structures-properties were established using Raman active modes as a media. [ABSTRACT FROM AUTHOR]

In this work, Cu-1.5 wt%Y (Cu-Y) and Cu-0.75 wt%Y-0.75 wt%La (Cu-Y-La) were prepared by mechanical alloying combined with spark plasm sintering and hot rolling, followed with annealing at different temperatures. The effects of the introduction of La and annealing temperatures on the microstructures, mechanical properties, electrical conductivity and thermal stability of Cu-Y alloys were investigated. Both Cu-Y and Cu-Y-La obtain the heterogeneous mixed grain structures composed of coarse grains and fine grains, and oxide nanoparticles are uniformly dispersed in Cu matrix. With the introduction of La, the grains and oxide nanoparticles are refined, and LaYO 3 nanoparticles with the coherent interfacial structure can be observed in Cu-Y-La. After annealing at 500 ℃, both Cu-Y and Cu-Y-La obtain the most excellent comprehensive tensile properties and highest electrical conductivity (63 %IACS for Cu-Y and 62 %IACS for Cu-Y-La). Benefited from effectively enhanced grain boundary strengthening and particle strengthening mechanisms induced by the combination effect of La and Y, Cu-Y-La shows higher strength than that of Cu-Y (after annealing at 500 ℃, 244 MPa of yield strength for Cu-Y and 300 MPa for Cu-Y-La). Meanwhile, benefited from improved dynamics stability of the Cu matrix induced by significantly refined precipitates and the formation of LaYO 3 nanoparticles with the coherent interfacial structure after introducing La, the better softening resistance is achieved by Cu-Y-La in comparsion with Cu-Y, and almost 100 ℃ improvement of the softening temperature is achieved (966 ℃ for Cu-Y-La and 870 ℃ for Cu-Y). • A novel system of Cu-Y-La alloy for the field of ITER is designed and prepared. • Effects of heat treatment on microstructure and properties of Cu alloys reinforced by rare earth elements are studied. • The significant improvement of mechanical property of Cu-Y alloy is achieved through the combination effect of Y and La. • The softening resistance of Cu-Y alloy is successfully improved through the combination effect of Y and La. [ABSTRACT FROM AUTHOR]

As a possible solid electrolyte material for solid-state sodium-based batteries, gallium-substituted Na 3 Zr 2 Si 2 PO 12 in the structure of Nasicon (sodium super ion conductor) has received hardly any attention so far, though Ga3+ has similar ionic radius close to that of Zr4+. Herein, a series of gallium-substituted Na 3 Zr 2 Si 2 PO 12 with formula of Na 3+x Zr 2-x Ga x Si 2 PO 12 (0 ≤ x ≤ 0.4) have been prepared through solid-state synthesis. The electrical, microstructural, and crystallographic performances of the developed solid electrolytes are systematically studied. In particular, the gallium-substituted Na 3.1 Zr 1.9 Ga 0.1 Si 2 PO 12 shows superior ionic conductivity of 1.06 × 10−3 S cm−1 at 25 °C, which is almost one order of magnitude higher than that of the pristine Na 3 Zr 2 Si 2 PO 12 , as well as low electronic conductivity of 6.17 × 10−8 S cm−1 and wide electrochemical stability window of 5 V vs. Na/Na+. This work demonstrates a new substituted strategy for exploring Na+-ion solid electrolytes. Image 1 • Substitution of Ga3+ for octahedral Zr4+ in Na 3 Zr 2 Si 2 PO 12 is proposed. • Tenfold increase in conductivity for Na 3.1 Zr 1.9 Ga 0.1 Si 2 PO 12 is achieved. • Conductivity dependence of bottleneck is demonstrated. [ABSTRACT FROM AUTHOR]