La-doped YFeO₃ ceramics, namely Y_1-x La _x FeO₃ (x = 0.1, 0.2, 0.3, 0.4) were prepared by sol-gel method and high-temperature sintering method, then the YFeO₃ ceramics before and after La doping was characterized by means of scanning electron microscope (SEM), X-ray diffractometer (XRD), energy dispersive spectrometer (EDS) and network vector analyzer (VNA). So that the effect of the La³⁺ doping amount on the micromorphology, phase constituents, chemical composition, electromagnetic parameters and microwave absorption performance of Y_1-x La _x FeO₃ were studied. The result shows that as the La doping amount increases, the grain size is gradually decreasing and the grain boundaries are gradually blurred of the ceramics, which may be related to the enhanced preferential orientation of grains and incomplete replacement of the doping atoms. The analysis results confirm that the prepared ceramics consist merely of the YFeO₃-type phase, and La³⁺ can replace the Y³⁺ position in the YFeO₃ crystal. It is clear that an appropriate amount of La doping can effectively increase the impedance matching and attenuation coefficients of YFeO₃ ceramic powder. The increase in the dielectric constant may be attributed to the hopping of electrons between Fe³⁺ and Fe²⁺ in the case of La doping. The effective absorption broadband (RL ≤ -10 dB) of Y_0.7La_0.3FeO₃ can reach 2.84 GHz.

The core-shell composite Co₃O₄/Co₉S₈, as electrode material was prepared by a two-step method. Firstly, Co₃O₄ nanowires were grown on Ni-foam by hydrothermal method, and then they were calcined. Secondly, Co₃O₄/Co₉S₈ core-shell composite materials on templates of Co₃O₄ nanowires were obtained via ion exchange reaction and sulfidation in the presence of thioacetamide (TAA). The nanowire core Co₃O₄ and shell Co₉S₈ are interconnected each other as uniformly distributed nanorods on the Ni-foam. Results indicated that by optimizing the TAA concentration during the second step, the electrode gained a higher number of active sites and improved electrochemical performance. At a current density of 2 mA·cm^-2, the electrode exhibited a specific capacitance of 3.54 F·cm^-2. Due to its excellent conductivity and efficient ion diffusion pathways, it achieved up to 3,000 charge-discharge cycles at a current density of 50 mA·cm^-2, while maintaining a high specific capacitance of 2 F·cm^-2 and stability after cycling. Additionally, by utilizing Co₃O₄/Co₉S₈ as the positive electrode and activated carbon as the negative electrode, an asymmetric supercapacitor was assembled. After 5,000 charge-discharge cycles, this device attained a capacitance retention rate of 100%, demonstrating outstanding cycling stability. The soft-pack quasi-solid-state asymmetric supercapacitor assembled with this Co₃O₄/Co₉S₈ electrode exhibits excellent mechanical flexibility and cycling stability.

Bulk Ti-5Al-5Mo-5V-3Cr (Ti5553) alloy was prepared by selective laser melting (SLM) technique, then the effect of laser power and scanning speed on the relative density, microstructural defects, and mechanical properties of the prepared alloy was assessed. The results indicate that as laser energy density increases, defects in the Ti5553 alloy decrease and relative density is improved. By laser power within the range 110-120 W and scanning speed 300-500 mm/s, the relative density of the alloy exceeded 99.99%. The main defects in the alloy include irregularly shaped lack-of-fusion defects and regular keyholes. Lack-of-fusion defects mainly existed in the alloys prepared by laser of lower energy densities (~111 J/mm³) however which decrease with the increasing laser energy density. Excessive energy density (~167 J/mm³) results in the formation of keyholes of a small volume fraction with regular shape, and good sphericity. Compression test results show that alloys of relative density above 99% exhibit high yield strength, reaching up to 864 MPa. These findings may provide a reference for the research and development in the application selective laser melting for manufacturing workpieces of Ti5553 alloy.

The isothermal thermal compression behavior of 9310 steel was assessed via Gleeble-3800 thermal simulation testing machine by applied pressing force up to 70% of the maximum value, with a range of strain rate 0.01-50 s^-1 at 1000-1200 ^oC, in terms of variation of the flow softening and strain hardening of 9310 steel by large strain (0.7-1.2). Then, the mechanism related with the competition of flow softening and strain hardening was clarified in combination with the microstructure evolution. The results show that the flow softening and strain hardening behavior of 9310 steels are affected by different factors in the range of different deformation parameters. When deformed within high temperature range (1080-1200 ^oC), the microstructure evolution is dominated by dynamic recrystallization (DRX), and the flow softening and strain hardening are mainly affected by the strain rate. The softening mechanism at high strain rate (5-50 s^-1) is DRX; The pinning effect of carbides is the main hardening mechanism at low strain rate (0.01-5 s^-1). When deformed within lower temperature range (1000-1080 ^oC), flow softening and strain hardening are significantly affected by strain rate and deformation temperature. With the increase of strain rate and the decrease of deformation temperature, the degree of strain hardening decreases gradually, and the influence of deformation thermal effect gradually increases. The hardening behavior by high strain rate at low temperature is related to the coarsening of DRX grains. There are a large number of original deformation austenite grains by high strain rate at low temperature, while the microstructure evolution is mainly dynamic recovery (DRV), and the flow softening is the result of the joint action of deformation heat effect and DRV. The observation of the deformed water-cooled structure and EBSD analysis showed that the DRX grains tended to form a typical martensite multi-level structure during the course water-cooling with phase transformation, however, which may be destroyed by the higher dislocation density in the original deformed austenite grains, thereby resulting in chaotic and disordered martensite morphology.

In-depth study of the damage mechanism of hard and brittle 6H-SiC materials during the grinding process with nano-particles is of great significance to improving the surface quality of 6H-SiC components. In the article, the surface deformation behavior of the bulk 6H-SiC materials during grinding with nano-diamond abrasives was simulated by means of molecular dynamics simulation, while revealing the subsurface damage mechanism and considering the effects of abrasive grain size and grinding speed. The results show that when the abrasive grain size is larger than 4.9 nm, as the grinding speed increases, the material removal first increases and then decreases, and the removal of 6H-SiC material is primarily based on adhesion. By a constant grinding speed, as the abrasive grain size increases, the damage depth, subsurface temperature, and lattice defect degree of the 6H-SiC workpiece first decrease and then increase. Additionally, the grinding speed has much significant impact on the subsurface damage depth and grinding force of the workpiece, for the abrasive grain size is 5.4 nm. It is expected that by adopting 5.4 nm abrasive grains and setting higher grinding speeds,the higher machined surface quality may be achieved within the simulation parameters range.

Nd-Fe-B permanent magnets are widely used in aerospace, new energy vehicles, wind power generation and many other fields due to their excellent performance. By increasing the resistivity of the Nd-Fe-B magnets, the temperature rise of the magnet can be effectively reduced and the working stability of the magnet can be improved. Herein, a novel technique was adopted to prepare the BN-doped hot-deformed Nd-Fe-B magnets, i.e. first, by spraying an appropriate amount of BN demolding agent onto the surface of the commercial fast-quenching Nb-Fe-B magnetic powders to obtain the BN-coated magnetic powders (namely 0, 0.2, 0.4, 0.6 and 0.8 of BN, in mass fraction respectively), subsequently, the hot-deformed bulk BN-doped Nb-Fe-B magnets were prepared with the modified powders as raw material by hot pressing process and then hot deformation process. The effect of different BN doping amount on the magnetic properties, resistivity, temperature stability and microstructure of the hot-deformed Nd-Fe-B magnets were studied. The results show that the sprayed BN presents good adhesion on the Nd-Fe-B magnetic powders; The introduction of BN by spraying can significantly improve the resistivity of the magnets, which increases from 153.5 μΩ·cm for magnets of the plain powders to 287.7 μΩ·cm for that of the powers coated with 0.8%BN, implying an increase of 87%. The grain orientation of the magnets can also be improved by the introduction of proper BN. With the increase of coated BN amount, the magnetic properties and temperature stability of the magnets decrease gradually. When the sprayed amount of 0.6% BN, the magnets has excellent comprehensive magnetoelectric performance: the maximum magnetic energy product (BH)_max is 36.67 MGOe; the remanence B_r is 12.48 kGs; the coercivity H_cj is 11.85 kOe; the resistivity is 254.8 μΩ·cm. It follows that this study provides a technical path to effectively improve the resistivity of magnets while maintaining high magnetic properties, so that the prepared magnets may be suitable for high operating temperature scenarios.

A kind of cold rolled aviation tube of TA18 type that has been subjected to recrystallization annealing treatment to produce an uniform initial texture. Subsequently, these tubes were subjected to a second round cold rolling again by the same deformation amount (60%) but different Q ratios (1.1-2.0). On this basis, the influence of cold rolling Q ratio on the plastic deformation texture evolution of TA18 aviation tube was studied by using the electron backscatter diffraction (EBSD) technique, in terms of the In-Grain Misorientation Axes (IGMA) and microstructures of cold rolled tubes with different Q ratios. The results show that the cold rolled tubes with different Q ratio present a "river like" fiber structure along the axial (RD) direction, showing the typical characteristics of large plastic deformation. With the increase of Q ratio, the grain orientation changes from the tangential direction (TD) to the one close to the normal direction (ND). The cold rolling Q ratio has a synergistic effect on the plastic deformation behavior and texture evolution of TA18 tube: with the increase of Q ratio, the Taylor axes distribution changes from <0001> to <10\overline{\mathrm{1}}0>, and the plastic deformation mechanism of cold rolled tubes changes from prismatic slip to pyramidal slip. The reason may be that when the Q ratio increases, the c axis of grains continuously shifts from TD direction to ND direction, and the Schmid factor of conical slip systems increases, which leads to the easy start of conical slip systems; At the same time, the <0001>//ND texture gradually replaced the <0001>//TD texture as the main texture type, and the radial texture factor at the base of the tube was continuously enhanced. In accordance with the AMS standard, when the cold rolling Q ratio is ≥ 1.49, the contraction strain ratio (CSR) of TA18 tubes meets the requirements.

A soft template was constructed by adjusting the amount of CTAB in a water/ethanol solution (volume ratio 4:1) with Pd(NO₃)₂·2H₂O as the Pd precursor, then Pd nanosheets were prepared via ultrasonic-assisted template technology. The nanosheets were characterized by XRD, FESEM, TEM, and UV-vis spectroscopy, and their electrocatalytic oxidation of glycerol was investigated by cyclic voltammetry and chronoamperometry methods. The results revealed that the obtained Pd nanosheets possessed abundant defects, including crystal face expansion, lattice distortion, dislocation, and twin boundary etc. These nanosheets had a thickness of approximately 8.10 nm and exhibited a mass activity of 4179.82 mA/mg for glycerol oxidation in alkaline media, which was 7.43 times higher than that of commercial Pd/C (562.77 mA/mg). Furthermore, the specific activity of the Pd nanosheets was 9.12 mA/cm², which was 5.81 times greater than that of the commercial Pd/C (1.57 mA/cm²). In addition, these Pd nanosheets also demonstrated high resistance against poisoning and excellent stability during glycerol oxidation reaction (GOR).