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High-entropy alloys (HEAs) with a face-centered cubic structure offer numerous advantages, including high plasticity, good processability, and high-temperature resistance. They are also suitable for use as materials in shaped-charge liners, which can cause significant damage. In this study, CoCrFeNi HEAs were prepared, and their mechanical characteristics were examined. The results indicated that the alloy exhibited good plasticity and processability. After dynamic compression, the samples were analyzed using electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). It was found that dislocation was the primary deformation mechanism at low strain rates. However, as the strain rate increased, the deformation mechanism shifted from dislocations to a combination of dislocations and twinning. The damage performance of the CoCrFeNi HEA was verified through a static penetration experiment using a conical charge. The results were then compared with simulation results obtained using the AUTODYN software. This study demonstrated that the CoCrFeNi HEA could form a condensed, stable-shaped charge jet, leading to efficient damage after penetrating the steel target plate. Therefore, after uniform treatment, the CoCrFeNi HEA can be utilized as a high-energy structural material to design shaped charge structures that achieve highly efficient damage. • CoCrFeNi HEA has excellent comprehensive mechanical properties. • CoCrFeNi HEA liner can form a continuous jet. • CoCrFeNi HEA jet has excellent penetration ability. • CoCrFeNi HEA exhibits the property of releasing impact energy. [ABSTRACT FROM AUTHOR]

Abstract: Composite of copper and 3mol% yttria-stabilized 5wt.% zirconia (3-YSZ) have been prepared by hydrogen () reduction of a homogeneous mixture of equably dispersed CuO and ZrO2 formed by three chemical processes. In these processes, the 5%ZrO2/Cu nano-composite has been formed in situ by (1) addition of NaOH solution to certain amount of dispersed Cu(NO3)2, ZrOCl2 and Y(NO3)3 alcohol solution, following filtration; or (2) by adding ammonia to ZrOCl2, Y(NO3)3 solution, then adding Cu(NO3)2 solution to the deposition; (3) the mixture of Zr(OH)4 and Cu(NO3)2·3H2O, mixing and heating the final composition in the three cases to acquire the blending. And calcined them at 500°C for 1h. The 5%ZrO2/Cu composites were fabricated by quenching and final sintering at 900°C for 90min in vacuum atmosphere. The three process were named process A, process B, and process C. The characterization of the composite samples has been done by XRD, SEM, TEM and metallography techniques. Results from XRD and TEM indicated that different crystal structure zirconia was formed in the three processes. In comparison, the composite microstructure of process B was more homogenous. The comparative conductivity and Vickers hardness were 64% IACS and 120, which were much higher than the other two processes. [Copyright &y& Elsevier]

Lead-free Ba 0.9 Ca 0.1 Ti 0.90 Sn 0.10 O 3 -x La 2 O 3 (x = 0–0.07 mol%) piezoelectric ceramics have been prepared at 1480 °C by conventional solid-state sintering process. The effects of La 2 O 3 addition on the microstructure, the piezoelectric and dielectric properties have been investigated. X-ray diffraction pattern confirmed the coexistence of the orthorhombic phase and tetragonal phase at around x = 0.03. SEM images indicate that the addition of La 2 O 3 restrain abnormal grain growth and lead to the formation of homogeneous microstructures during sintering. Main piezoelectric parameters are optimized at x = 0.03 with a high piezoelectric coefficient (d 33 = 496 pC/N), a planar electromechanical coupling factor (k p = 41.7%), which indicates that the Ba 0.9 Ca 0.1 Ti 0.90 Sn 0.10 O 3 -x%La 2 O 3 ceramics are promising for lead-free practical applications. [ABSTRACT FROM AUTHOR]

The Ba 0.97-x Ca x La 0.03 Ti 0.90 Sn 0.10 O 3 (x = 0.02–0.10) lead-free piezoelectric ceramics were fabricated via conventional solid-state sintering process at 1480 °C. The effects of Ca 2+ ions substitution on microstructure and electrical properties of the ceramics were researched. Ca 2+ ions substitute for A-site Ba 2+ ions to enter the unit cell maintaining the perovskite structure of th solid solution and the orthorhombic phase and tetragonal phase coexist in the composition with x = 0.04 to 0.10. SEM images confirmed the inhibiting effect of Ca ions on the grain growth process of the Ba 0.97-x Ca x La 0.03 Ti 0.90 Sn 0.10 O 3 ceramics. Uniformly distributed microstructures with high relative densities above 94.71% were developed with the further addition of Ca 2+ ions. Main piezoelectric parameters were optimized at x = 0.04 with a high piezoelectric coefficient (d 33 = 541 pC/N), a planar electromechanical coupling factor (k p = 45.7%), The analysis on the temperature dependence of dielectric permittivity approved the existence of the mixed ferroelectric-relaxor features in all the BCLST samples. The remnant polarization (Pr) reaches an extreme value of 7.81 μC/cm 2 at x = 0.08. [ABSTRACT FROM AUTHOR]

To reinforce the electrochemical properties of next-generation lithium-sulfur batteries (LSBs), modified interlayers emerge as a promising approach to suppress the polysulfide shuttling effect and improve cycle stability. This work presents a straightforward approach to produce a YCl 3 -doped carbonized cellulose paper (YCl 3 -CCP) as an interlayer, which has been demonstrated to significantly suppress the shuttle effect in LSBs. The synergistic effect of graphite and Y 2 O 3 of the interlayer of YCl 3 -CCP can capture lithium polysulfides through strong absorption, thereby improving both cycle stability and coulombic efficiency. Herein, our results indicate that LSBs with interlayers of YCl 3 -CCP achieve a discharge capacity of 903 m Ah g−1 at 2 C, with a capacity retention of 77.3% over 500 cycles and an average capacity fading rate of 0.045% per cycle. Overall, this work provides a promising strategy for addressing the polysulfide shuttling effect in LSBs and opens up new avenues for further research in this area. • Graphitic carbon catalysis is employed to introduce YCl 3 for in-situ generation of G@Y 2 O 3 under high-temperature. • The synergistic reaction between Y 2 O 3 and graphite maintains the original structure during adsorption. • Synergistic G@Y 2 O 3 reaction enhances polysulfide adsorption, suppressing shuttle effect in LSBs. [ABSTRACT FROM AUTHOR]

The Ba 0.90 Ca 0.10 Ti 0.90 Sn 0.10 O 3 -xCeO 2 (x = 0.0.09) ceramics (BCST-xCe, x = 0–0.09) were prepared by traditional solid-state sintering method. All the BCST-xCe samples present pure perovskite structures with the coexistence of orthorhombic phase and tetragonal phase. Ce ions occupy the B-site of the BCST lattice in the form of Ce 4+ , which can be attributed to the decrease of the dissipation factor and T d with increasing Ce content. Small amount of CeO 2 (x = 0–0.03) motivates the formation of denser microstructures. The optimized piezoelectric parameters were obtained at x = 0.03 with d 33 = 541pC/N, k p = 47.5%, which can be attributed to the MPB effect and the dense microstructure induced by the Ce doping. Dielectric behavior of all the sintered ceramics describes a mixed ferroelectric-relaxor feature. With the increasing of Ce content, the remnant polarization Pr decreases from 10.78μC/cm 2 to 7.94μC/cm 2 . [ABSTRACT FROM AUTHOR]

As one of the most efficient trace element to improve the mechanical properties of alloys, scandium (Sc) has attracted much attention for aluminum alloys in recent years. In this study, a new kind of Al–Zn–Mg–Cu–Sc–Zr alloy has been designed, and the evolution of microstructure and properties during the processes including homogenization, hot extrusion, solid solution and aging has been investigated. The alloy aged at 120 °C reveals a dual-peak aging phenomenon which is attributed to the overlap of the formation of Guinier–Preston (GP) zones and η′ phases. Consequently, excellent mechanical properties can be obtained (UTS = 747 MPa, YS = 721 MPa and EI = 10.9%) when the alloy is aged at 120 °C for 15 h. The improvement of the mechanical performance is mainly attributed to the grain refinement by the primary Al 3 (Sc, Zr) and the dispersion strengthening of the secondary Al 3 (Sc, Zr). Thus, the combined additions of Sc and Zr play an important role for the strengthening of the alloy. [ABSTRACT FROM AUTHOR]

Layered Li 1+ x Ni 0.5 Co 0.2 Mn 0.3 O 2 ( x = 0, 0.02, 0.04, 0.06, 0.08) materials were synthesized using the co-precipitation method. Rietveld refinements measurements reveal that the concentration of Ni 2+ -3b ions decreases from 0.06 to 0.043, with x changing from 0.02 to 0.08. The initial coulombic efficiency improves with the increase in the content of Li-excess because the content of Ni at the 3b site decreases with the increase of Li-excess in the samples from 0 to 0.08. The analysis indicates that Li 1.08 Ni 0.5 Co 0.2 Mn 0.3 O 2 exhibits the largest diffusivity value due to the dependence of the diffusion coefficient of lithium ions on the content of Ni in the 3b sites. [ABSTRACT FROM AUTHOR]

• The major highlight of this paper is how to improve the thermal stability of γ I ′ phase by investigating its directional coarsening behavior. • The second highlight is clarifying the kinetics of γ I ′ directional coarsening and its connection mode. • The third highlight is clarifying the influence of initial radius, number, volume fraction and γ channel distance on the kinetics of γ I ′ directional coarsening. • The forth highlight is clarifying the influence of lattice misfit, elemental diffusion and interfacial composition width on γ I ′ directional coarsening. Polycrystalline Ni 3 Al-based superalloy with up to 70% γ ′ phase owns excellent strength at around 1100 °C. It has been successfully used as a substitute for turbine blade crown, which is one of the aircraft components working in the severest environment (i.e., sometimes nearly overheating). However, few studies concentrate on the coarsening resistance and phase thermal stability in this newly designed polycrystalline superalloy at the working temperature, hence, directional coarsening behavior of primary γ ′ (γ I ′) has remained restricted. This paper investigated directional coarsening behavior of γ I ′ during aging treatment (1100 °C) after overheating at 1270 °C with furnace cooling (SFA), air cooling (SAA) and water cooling (SWA) respectively. It clearly showed that γ I ′ grew into lamellar and gradually became irregular during the directional coarsening process. Moreover, its morphological combination mode was illustrated. Since parallel short lamellar γ I ′ connected each other, long lamellar formed. When perpendicular long lamellar γ I ′ connected each other, it became L -type or T-type, i.e., precursor of irregular γ I ′. The kinetics of directional coarsening regime of γ I ′ was in line with the matrix-diffusion - controlled (MDC) theory according to the evaluation of γ I ′ size. This was caused by higher migration of γ I ′ interfaces than the diffusion of solute elements. It was also confirmed that driving force of directional coarsening mainly depended on the competition of elemental diffusion, lattice misfit distribution and γ channel distance. [ABSTRACT FROM AUTHOR]

In this work, hot compression deformation behavior and processing maps of ATI 718Plus superalloy were studied by isothermal compression test on Gleeble-3800 thermal simulation testing machine. The results showed that under the present conditions (with deformation temperature range of 1030–1180 °C, strain rate of 0.01–10 s−1 and deformation amount of 50%), flow stress decreased with the increasing of deformation temperature and decreasing of strain rates. Meanwhile, simplified and strain-compensated classical Arrhenius constitutive equation models were established respectively, and strain-compensated constitutive equation improves the accuracy of flow stress prediction. In addition, processing maps showed that the optimal hot processing parameter ranges were 1140–1180 °C with strain rate of 0.01–0.1 s−1 respectively. The effects of strain rate and deformation temperature on microstructure evolution was investigated and low strain rate and high deformation temperature are conductive to DRX. • The strain compensation constitutive equation for 718Plus was established and accuracy was compared with simplified equation. • The optimal parameter range of hot working is determined by the establishment of hot processing maps. • Combining the processing maps and microstructure observation the evolution behavior of DRX structure is described. [ABSTRACT FROM AUTHOR]

In this work, precipitation behavior and mechanical performances of A356.2 alloy (treated by Al–6Sr–7La composite refinement-modification agent) were studied for the first time. Artificial aging treatment (T6) and long-time natural aging treatment (>10,000 h, T4) were applied to clarify the precipitation and growth behavior of Mg 5 Si 6 phase. The results show that vacancies and dislocations formed during solution treatment promote the nucleation and growth of Mg 5 Si 6 phase in the eutectic area during the subsequent aging process. During the T6 treatment, the growth of Mg 5 Si 6 phase is promoted due to the interaction of atomic diffusion channel caused by higher Si concentration gradients and dislocations, leading to a large number of uniform distributed spherical Mg 5 Si 6 phase in eutectic area. While, for the T4 treated alloy, atomic clusters with short rod-like Mg 5 Si 6 phase exists inside the alloy. In addition, T6 treatment resulted in significant improvement of tensile strength (UTS), yield strength (YS) and vickers hardness (HV) compared with the T4 treated alloy and the reasons were discussed. • Precipitation behavior of A356.2 alloy (treated by Al–Sr–La) in eutectic area was clarified. • Precipitation mechanism of Mg 5 Si 6 both under T6 and T4 were found. • Mechanical performances of Al–Sr–La treated A356.2 alloy (treated by Al–Sr–La) were investigated. [ABSTRACT FROM AUTHOR]