In order to improve the surface hardness and wear resistance of Ti-6Al-4V alloy, a cladded coating of TiO₂ and TiN was prepared on the surface of Ti-6Al-4V alloy by laser cladding, and the microhardness, wear resistance, microstructure and element distribution of the coating were explored. Compared to the substrate, the surface hardness and wear resistance of the coating are significantly improved. It is shown that with TiO₂ and TiN powder in a mass ratio of 1∶9, the hardness and specific wear rate of the coating can reach 1 936.1HV_0.1 and 2.06×10^-14 mm³/(N·m), respectively, which are 5.4 times and 3.26 times those of the substrate. The main components of the coating include α-Ti, TiN, and TiN_0.6O_0.4, which is the reason for the significant increase in hardness and wear resistance of the TiO₂-TiN cladded coating. The research results provide a theoretical and experimental basis for improving the hardness and wear resistance of Ti-6Al-4V alloy by laser cladding technology.

CiteSpace, as a bibliometric analysis tool, was firstly used to quantitatively analyze and visualize keyword clusters, co-citation relationships and burst terms for scientific literature on Laves phase used for high-temperature materials in the Web of Science from 2003 to 2023. A timeline chart of keyword clustering reflects the fundamental development status of Laves phase research in the search interval, revealing two hot topics in frontier research: one is improvement of room temperature brittleness or synergistic improvement of strength and plasticity of multi-phase high-entropy alloys reinforced by Laves phases, another is the effect of Laves phase precipitates on the microstructure and properties of heat-resistant alloy steels (P92, 12Cr and G115) at 600-650 ℃, at which creep occurs. The timeline chart of keyword clustering is consistent with the chart of relationship between literature and author in citation networks, both reflecting the activity of Laves phase research. In the future, those key authors and publications with high-quality achievement mined by the visualized patterns and trend should be paid more attention.

The effect of heat treatment parameters on the microstructure and properties of QAl11-6-6 aluminum bronze alloy extruded rod was explored by performing orthogonal test, in combination with metallographic microscope, X-ray diffractometer, scanning electron microscope and hardness tester. The results show that the microstructure of extruded aluminum bronze alloy consists of α, κ (AlFe, AlFe₃, AlNi), γ₂, and the remaining β′ phases; the heat treatment including solid solution and aging can effectively improve the hardness of the alloy extruded rod; the influence of four process parameters on the hardness of the alloy is in the following descending order: aging time > aging temperature > solid solution time > solid solution temperature. The sample was quenched by water cooling after solid solution at 910 ℃ for 45 min, and then treated by aging at 450 ℃ for 150 min. The hardness of the alloy was increased to 40.1HRC from previous 33.4HRC in the extruded state, presenting obvious age hardening effect. It is found that precipitation of more martensite-like β' was the main reason for significant increase in hardness of the alloy after aging treatment.

A high-strength Al-Si-Mg alloy was prepared by adopting selective laser melting (SLM), and then compared to the as-cast Al-Si-Mg alloy in terms of phase composition, microstructure, element distribution, crystallographic characteristics, and mechanical properties. It is found that Al-Si-Mg alloy prepared by SLM consists of α-Al matrix and eutectic Si particles, and the diffraction peaks of α-Al solid solution shift to lower angles due to the solid solution strengthening effect of Fe and Mg elements. The Al-Si-Mg alloy prepared by SLM has grain size approaching 18.35 μm, the dislocation density of 1.91×10¹⁵/m², the surface hardness of (117.8±4.7) HV, the tensile strength of (436±13) MPa, and the elongation of (7.98±0.27)%, presenting superior performance than the as-cast Al-Si-Mg alloy. The alloy prepared by SLM technology is under the synergetic effect of fine grain strengthening, solid solution strengthening, dislocation strengthening and second phase strengthening, and the ductile fracture is its main failure mechanism.

The effect of solid state diffusion of Li on the polarization behavior of Li-Al alloy anode was studied, and Li-Al electrodes with different specific surface areas and Cu@Li electrodes without the effect of solid state diffusion of Li were prepared. The polarization behavior of electrodeposited Li-Al alloy with a deposited capacity of 0.51 mAh/cm² in a half cell and a full cell were investigated by using galvanostatic charge-discharge measurement, cyclic voltammetry, electrochemical impedance spectroscopy (EIS), and galvanostatic intermittent titration technique. The results show that the solid-state diffusion of Li in Li-Al is the main reason for the polarization of Li-Al electrode in a half cell and a full cell, and the diffusional lithium trapping will increase the internal resistance of the cell, bringing in enhanced polarization phenomenon and finally resulting in the low discharge potential of about 1.84 and 1.55 V for Li-Al‖S battery. Surface α-Al layer causes diffusional lithium trapping, and disrupting it can not only increase the Li⁺ concentration in the electrolyte and promote the precipitation of Li₂S, leading to reduced polarization, but also increase discharge voltage of LiAl‖S battery to approach the thermodynamic discharge potential.

The innovation efficiency of each link of China's non-ferrous metal-new energy industrial chain was measured based on a four-stage DEA model, and its influencing factors were analyzed with the Tobit model. Based on the study, the following conclusions can be made: after SFA model adjustment, the four links of the industrial chain, i.e. mineral products, refined products, new energy materials and new energy application, can be arranged in descending order in terms of innovation efficiency, and pure technical efficiency is the key factor restricting the improvement of the innovation efficiency of each link of the industrial chain; the innovation efficiency of the industrial chain also presents the characteristics of being stronger in the west and weaker in the east in terms of spatial distribution; state-owned enterprises can demonstrate high innovation efficiency than non-state-owned enterprises; the concentration of suppliers, enterprise size, and the quality of employees are positively correlated to the innovation efficiency, while the degree of market competition, the debt to asset ratio, and the equity concentration are negatively correlated to the innovation efficiency. In order to improve the innovation efficiency of the industrial chain, more efforts should be made in policy support for reducing innovation risks of new energy enterprises, increasing the returns of new energy enterprises, and promoting the formation of industrial clusters.

In order to explore the overall stability of slope before and after local failure, as well as the effect of excavation method on slope stability, the slope project on the north side of Jingxi-Barak mining area in Jinchuan of Xinjiang was taken to study local failure characteristics of slope and slope stability under different excavation state by adopting distinct element method. It is found that the distribution of the maximum main stress has a great impact on the slope stability, and the factor of safety for slope stability tends to decrease first and then increase from the stage before local failure to the stage after failure; with more excavated benches, the factor of safety for slope stability tends to increase first and then decrease; with the excavated benches more than 1, the overall factor of safety of the slope meets the requirements; with slope angle less than or equal to 60°, the overall factor of safety also meets the requirements, and the suitable slope angle is 60°.

A seabed collector vehicle usually carries a large amount of sediments during mining seabed polymetallic nodules. For reducing the environmental impact caused by tail water discharged in the mining, two kinds of high efficiency and low diffusion desliming pretreatment devices, with twine-drum spiral structure and a direct discharge device with arresting mesh structure, respectively, have been developed, which integrates a jet-assisted transport testing equipment, and is also equipped with an online monitoring system. The desliming effect and environmental performance of the developed device was evaluated by performing computational fluid dynamics simulations and laboratory tests. It is found that the direct discharge device with arresting mesh can pretreat tails with desliming rate over 98%, and this pretreatment device can make quick separation of nodules from sediment, and also lead to subsequent quick settlement of the separated sediment, thus effectively controlling the plume caused by collector in the mining. It is concluded that this developed pretreatment device can improve the lifting efficiency in the mining and mitigate the pollution of tails in the deep-sea mining from the source.

According to the relative position between interbedded surrounding rock and the peripheral holes, the relationship between bedding planes and the connecting line of the adjacent blastholes was classified into three kinds. Mechanism for bedding planes bringing impact to crack propagation in rocks between blastholes by blasting under typical work conditions (with bedding planes on the perpendicular bisector of the connecting line of blastholes) was explored by the LS-DYNA numerical simulation; and the effect of bedding planes in a different relative position to the connecting line of blastholes on the blasting effect of surrounding rock was also studied. It is found that the propagation speed of blasting vibration waves in sandstone is slightly higher than that in sandy mudstone. Under blasting loads, the surrounding rock above both softer layer and the beddings suffer severe damage. The superposition of two-blasthole blasting vibration wave peaks intensifies the damage to the surrounding rock. The blasting effect is poor when the bedding plane penetrates the blastholes, but the blasting effect is ideal if the bedding plane is on the perpendicular bisector of the connecting line of blastholes.

To study the distribution of flow and pressure in the slurry pipeline of large-diameter slurry shield, Simcenter Flomaster was used to simulate the slurry pipe for calculation, and a one-dimensional model was established for the slurry pipe of large-diameter slurry shield. The distribution of flow and pressure in the pipeline under different working conditions by changing the valve opening degree, fluid density and rotating rate of pump were recorded, so as to obtain the optimal flow distribution. The calculation results show that valve opening degree, fluid density and rotating rate of pump all have a certain influence on the distribution of flow and pressure in the slurry pipeline system. By increasing valve opening degree, the flow rate in the pipeline increases and the pressure difference between two ends of the pump is reduced; as the fluid is changed from clear water to slurry, the flow rate in the pipeline increases and the pressure difference between two ends of the pump decreases; as the pump rotates at a lower rate, both the flow rate and the pressure difference are reduced. If the rotating rate of discharging pump is too low, the discharging pipe can be kept operating normally by increasing the rotating rate of the discharging pump or adding another pump in series.