Wear-resistant and corrosion-resistant coatings manufactured by laser cladding technology is used to solve the wear and corrosion problems of parts in harsh environments. It has good prospects for development. In this paper, the development history of laser cladding technology is briefly introduced, and the research progress of the influence of laser cladding technology on the preparation of wear-resistant and corrosion-resistant coatings is summarized emphatically at home and abroad, as well as the relationship between the change of molten pool and laser cladding process parameters and the structure properties of the cladding layer. The research progress of laser cladding technology for wear-resistant and corrosion-resistant coatings in specific application parts and working conditions is also described, including parts of hydraulic engineering equipment, aerospace equipment, petroleum mining equipment, etc. Finally, it summarizes the key issues that restrict the comprehensive industrial application of the technology, as well as the research directions that need to be carried out in terms of process and equipment.

Copper materials occupy an important position in modern industry, but it is limited by performance shortages such as strength, wear resistance and stability, etc. Therefore, introducing the reinforcement into the copper matrix to prepare copper composite materials with excellent comprehensive performance through powder metallurgy technology has become a hot spot in the field of copper materials research. Even, multi-component and multi-scale synergistic enhancement is employed to design copper-based materials and obtain copper-based composite materials with better comprehensive performance to meet the requirements of more application fields. This paper reviews the research progress of common synergistically strengthened copper matrix composites, the method of introducing the reinforcing phase into the copper matrix, the synergistic enhancement effect, and mechanism, etc. At last, the development direction of synergistically strengthened copper matrix composites and the problems that need to be solved are given.

The hollow SiO₂ microspheres were prepared through the hard template method and sol-gel method by using self-made polystyrene (PS) as template, cetyltrimethyl ammonium bromide (CTAB) as cationic surfactant and Tetraethyl orthosilicate (TEOS) as silica source. Effects of heating rate, content of CTAB, TEOS and ammonia on the morphology of hollow SiO₂ microspheres were discussed. The phase, morphology and mesoporous structure of hollow SiO₂ microspheres were characterized by XRD, TEM, SEM, TG and FTIR, which shows the successful preparation of hollow silica sphere. The particle sizes of hollow SiO₂ microspheres are 2-5 μm and the thickness is 117 nm. The hollow SiO₂ microsphere wall damage with the increase of heating rate. With increasing CTAB content, the number of nanospheres increase and the particle sizes of nanospheres decrease. With increasing TEOS content, the thicknesses of spheres increase until nanospheres are formed. When ammonia is less than 4 mL, hollow SiO₂ microsphere cannot be formed. When ammonia is greater than 4 mL, hollow SiO₂ microsphere have rough surface with solid particles. The optimized conditions are determined as follows: the heating rate is 0.5 ℃/min, the amount of CTAB is 0.05 g, the amount of TEOS is 0.3 mL, the amount of ammonia is 4 mL and then hollow SiO₂ microspheres are treated through filtering and cleaning.

Porous alumina ceramics are widely used as refractory materials, electrical insulators, wear-resistant mechanical parts, filtering materials and catalytic support due to their excellent mechanical properties, corrosion resistance, large specific surface area and stable chemical properties. The pores in porous alumina ceramics are commonly created by partial sintering, replica, sacrificial template or direct foaming method. Specific porous structure and porosity can be obtained by employing appropriate pore-creating method. Conventional sintering of alumina ceramics is usually characterized by high temperature, long duration, easy formation of coarse grains and residual pores. The application of advanced sintering technologies such as oscillatory pressure sintering, spark plasma sintering and microwave sintering can effectively overcome these shortcomings and comprehensively improve material properties. In order to provide references for the investigation, development and application of novel porous alumina ceramics, we reviewed the research progress on two aspects including pore-creating method and sintering technology involved in the fabrication process of porous alumina ceramics.

The inherent brittleness greatly limits the wide application of high performance ceramic materials in the industrial field. In this paper, ultrahigh toughness 3YSZ ceramics were prepared by electric field assisted dynamic hot forging. The microstructure evolution and mechanical properties of 3YSZ ceramics under the coupling of electric field and dynamic force field were studied. The results show that: under the conditions hot forging for 10 min at a constant furnace temperature of 1 000 ℃, electric field strength of 20 V/cm, current density of 140 mA/mm², and dynamic pressure of (50±10) MPa, the Vickers hardness and fracture toughness of 3YSZ ceramic reache (12.40±0.58) GPa and (10.69±0.33) MPa·m^1/2, respectively, which increase 11.5% and 54.9% compared with the conventional sintered ceramic. The remarkable improvement of toughness mainly due to the stability of the tetragonal phase in 3YSZ ceramics reduced by electric field assisted dynamic hot forging, which makes it easier to undergo phase transformation when induced by external force, so as to effectively inhibit crack propagation. Electric field assisted dynamic hot forging technology has the advantages of no need to add reinforcement phase and remarkable toughening effect, which provides a new path for toughening high performance 3YSZ ceramic materials.

Carbon-coated cobalt phosphide (CoP/C) powders were prepared by high temperature pre-annealing and further phosphating using Zeolitic Imidazolate Framework-67 (ZIF-67) and Co(NO₃)₂∙6H₂O as precursor. CoP/C powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and the electrocatalytic hydrogen evolution experiments were also carried out. The results show that after calcination at high temperature, the organic components of ZIF-67 are transformed into conductive carbon skeleton, and cobalt ions are transformed into elemental cobalt nanoparticles embedded in the carbon skeleton. After further phosphating, pure phase CoP/C powders are obtained. CoP/C powders exhibit good catalytic activity with an overpotential of 64 mV and a Tafel slope of 66 mV/dec, which maintains high catalytic activity after 15 h for electrocatalytic hydrogen evolution.

Si₃N₄ ceramics exhibit excellent mechanical properties due to their strong covalent bonding characteristics, however, this characteristic makes them difficult to secondary process, severely limiting their widespread industrial applications. In this study, dynamic hot forging (DHF) technology was employed to process commercial Si₃N₄ ceramics, the effects of hot forging temperature on the microstructure and mechanical properties of materials were studied. The results indicate that under a dynamic pressure of (60±5) MPa and a hot forging temperature of 1 800 ℃, the Si₃N₄ ceramics exhibit optimal mechanical properties, with a hardness of 13.84 GPa, a fracture toughness of 6.88 MPa·m^1/2, and a bending strength reaching 925 MPa. All performance metrics significantly surpassing those of the original samples. This performance enhancement is primarily attributed to two key factors: firstly, the elimination of defects such as pores during the hot forging process, and secondly, the structural texturing effect induced by dynamic pressure. The DHF technology developed in this study provides an effective new method for the secondary processing and strengthening of high-performance difficult-to-machine ceramic materials.

As one of advanced Cu-based alloys, oxide particle-enhanced dispersion-strengthened copper alloys are widely used in rail transit, national defense industry and nuclear reactors. In this paper, copper alloy composites reinforced with Al₂O₃, Y₂O₃ and ZrO₂ oxide particles are reviewed, and their fabriaction, microstructure and physical properties are summarized. The relative problems existing in development and application are given, and the development trend is analyzed and forecasted.

Copper nitrate and trimesic acid were used as raw materials to fabricate octahedral HKUST-1 by hydrothermal method. HKUST-1 was calcined in Ar protective atmosphere and Cu/C nanoparticles were derived through carbothermal reduction reaction. The Cu@Pt/C catalyst was obtained by soaking Cu/C in potassium chloroplatinic acid solution by galvanic displacement. The morphology and microstructure of Cu@Pt/C catalyst as well as its electrocatalytic activity towards methanol were further characterized by SEM, XRD, XPS and cyclic voltammetry (CV). The results show that the as-prepared Cu@Pt/C catalyst retains special octahedral structure of HKUST-1 and has a core-shell structure formed by Pt coating on the surface of Cu. The electrochemically active surface areas (ECSA) measured by cyclic voltammetry curves in H₂SO₄ solution is 74.3 m²/g, about 1.47 times as much as that of commercial Pt/C. The cyclic voltammetry curves in H₂SO₄+CH₃OH solution shows the ratio of positive sweep peak current density to reverse sweep peak current density J_f/J_b is 2.18, which is much higher than that of commercial Pt/C. Thus Cu@Pt/C catalyst has better electrocatalytic activity to methanol oxidation and better CO tolerance.

Ni₃Fe/Ni₃S₂ oxygen evolution catalysts were synthesized by two-step hydrothermal method using Fe(NO₃)₃·9H₂O and Na₂S·9H₂O as Fe source and S source, respectively, and nickel mesh (NM) as the Ni source and support substrate. The microstructure and morphology of the catalysts were analyzed by XRD, XPS, SEM, and TEM, and the electrochemical properties were tested by an electrochemical workstation. The results demonstrate that the Ni₃Fe/Ni₃S₂ catalyst synthesized by the two-step hydrothermal method has rich three-dimensional nanoflower morphology, which enhances the spatial utilization of the catalyst. Ni₃S₂ exposes a high refractive index $\{\bar{2}10\}$. crystalline surface, which contributes to the synergistic effect with the (111) crystalline surface of Ni₃Fe to enhance the catalytic activity. The oxygen evolution overpotential is 229 mV at a current density of 10 mA/cm² in 1 mol/L KOH (25 ℃), the overpotential is 335 mV for a current density of 600 mA/cm² in 5.35 mol/L KOH (80 ℃), and the decay rate of the overpotential is only 2.39% after 6 000 cyclic voltammetry cycles. It demonstrates that the catalyst has good oxygene evolution performance and stability.

To improve the corrosion resistance and wear resistance of piston rod, Fe-based coatings with martensite and ferrite structure were prepared on 45^# steel by laser cladding. The phase compositions, microstructure and elements distribution of the coatings were characterized by X-ray diffractometer, scanning electron microscope and X-ray energy dispersive spectrometer. The microhardness and wear resistance of the coatings were tested by Vickers hardness tester and dry sliding friction wear tester. Furthermore, the corrosion resistance of laser cladding Fe-based coatings was studied by electrochemical workstation. The results show that the phase of laser cladding Fe-based alloy coating is mainly composed of α-Fe, Ni-Cr-Fe, γ-(Fe,C), Fe_9.7Mo_0.3. The main microstructure is martensite, ferrite and a small amount of residual austenite. The dendritic structure of coating is uniform, compact, without cracks or pores. The coating and the substrate are bonded metallurgically. The hardness and wear resistance of the coatings increase with increasing laser power. The average microhardness (HV) of the coatings at 2.4 kW is as high as 647.64 and the wear resistance is 9.37 times that of 45 steel. The wear mechanisms of the coatings are abrasive wear. The corrosion resistance of laser cladding Fe-based alloy coating firstly increases and then decreases with the increase of laser power. When the laser power is 2.0 kW, the coating has the best corrosion resistance, which is significantly higher than the commonly used carbon steel, stainless steel and electroplating hard for piston rods. It can replace electroplated chromium in related fields.

Ni and Co co-doped amorphous selenide was synthesized on nickel mesh as hydrogen evolution catalyst electrode by electrode position method, and the morphology and microstructure of NiCoSe electrode were observed and analyzed by scanning electron microscopy, X-ray diffractometer, transmission electron microscopy and X-ray photoelectron spectrometer, and the electrocatalytic hydrogen evolution performance of the electrode was tested by electrochemical experiments. The results show that the NiCoSe electrode surface is embedded with NiCoSe spherical particles, and no obvious cracks. NiCoSe compound is amorphous and can provide more low-energy barrier cavities. The appropriate ratio of Ni and Co co-doping can modulate the electronic structure of Se to shift the electronic binding energy of the catalyst, which in turn enhances the adsorption ability of the catalyst to H atoms, resulting in a higher intrinsic catalytic activity of the NiCoSe hydrogen evolution catalyst electrode. At a current density of 10 mA/cm² in 1 mol/L KOH solution, the overpotential of the NiCoSe cathode is 83 mV, and the Tafel slope is 108.98 mV/dec. The step controlling the reaction rate is the adsorption process of the catalyst on H atoms. The current density decay rate is less than 5% after 60 h electrolysis.

Dense Al₂O₃-ZrO₂ composite ceramics were prepared by pressureless sintering using α-Al₂O₃ and yttria stabilized zirconia powders as raw materials, conducting heat treatment under critical electric field, and the microstructure and mechanical properties of the composite ceramics were investigated. Results indicate that the onset temperature of flash sintering for sintered dense Al₂O₃-ZrO₂ composite ceramic is 308 ℃ under an electric field of 900 V/cm. Al₂O₃-ZrO₂ eutectic zone is in-situ synthesized in the dense Al₂O₃-ZrO₂ composite ceramic using flash sintering at 1 200 ℃ and 700 V/cm. The flash sintered ceramic is divided into three zones: composite zone, transition zone, and eutectic zone. In the composite zone, the Al₂O₃ and ZrO₂ phases are irregular shapes and uniformly distributed, where there is similar microstructure to the sintered ceramic. In the transition zone, the abnormal grain growth is observed, and the coarse Al₂O₃ and ZrO₂ phases are evenly distributed. In the eutectic zone, it possesses the typical microstructure of Al₂O₃-ZrO₂ eutectic ceramic. The Vickers hardness and toughness of eutectic zone are 17.94 GPa and 3.51 MPa·m^1/2, respectively, which are comparable to those of Al₂O₃-ZrO₂ eutectic ceramic fabricated by directional solidification technique.

Magnetically responsive ferroferric oxide (Fe₃O₄) nanoparticles were prepared by solvothermal method using ferric trichoride (FeCl₃) as the iron source and poly (styrene sulfonic acid-co-maleic acid) (PSSMA) sodium salt with two different chemical structures as surfactants. The effects of PSSMA surfactants with different structures and reaction conditions on the morphology, particle size, and photonic properties of Fe₃O₄ nanoparticles were investigated. The results show that the Fe₃O₄ particles are nearly spherical and surface is rough when using PSSMA with n(SS)∶n(MA)=1∶1 as surfactant in strong alkali environment, and particle size increases with increasing water content. Using PSSMA with n(SS)∶n(MA)=3∶1 as surfactant in weak alkali environment, the particles are regular spherical and surface is smooth, and the size increases with increasing Fe³⁺ content. It is more suitable for the generation of superparamagnetic Fe₃O₄ nanoparticles with uniform particle size and good monodispersity in weak alkaline environment due to the more abundant sulfonic acid group on the surface. This Fe₃O₄ nanoparticle dispersion system can rapidly form ordered photonic crystal nanoparticles under the action of external magnetic field, and obtain excellent tunable structure color.

Pure copper and copper alloys attract more and more attention due to their outstanding properties such as excellent electrical and thermal conductivities, ductility and high corrosion resistance. In this work, the research progress on the process characteristics, mircostructure evolution and mechanical properties of 3D printing pure copper and copper alloys in recent years were mainly summarized. The results show that the major challenge of pure copper and copper alloys fabricated by laser selective melting and laser melting deposition is to reduce the high reflectivity to the laser which can improve the density of the parts, manupulate the microstructure and obtain excellent mechanical properties. Process parameter optimization of selective electron beam melting and binder jetting need to be addressed due to the lower density and greater shrinkage of parts respectively, although it can overcome the problems caused by higher laser reflectivity of pure copper and copper alloys. Besides, this work introduced the application prospects about 3D printing of pure copper and copper alloys. Finaly, the progress on 3D printing of pure copper and copper alloys were also summarized and prospected.

The stability, mechanical properties, and electronic structure of transition metal (TM, TM=Ti, V, Cr, Y, Zr, and Hf) elements doped tantalum nitride (Ta₇TMN₈) were investigated by first-principles calculations. According to the calculation results of structure and stability, all the doped compounds are stable, and Ta₇TiN₈ is energetically more favorable than others. The doping of Y, Zr, and Hf can cause lattice and volume expansion of TaN, while Ti, V, and Cr play an opposite role. The calculated mechanical properties reveal that the addition of Ti and V can significantly improve the shear modulus, elastic modulus, and theoretical hardness of TaN, while doping Cr can only increase the volume modulus but significantly decrease the theoretical hardness. Based on the calculation results of the total and partial density of states of Ta₇TMN₈, the density of states at the Fermi level indicates that all compounds exhibit metallic nature. The contribution of Ti-3d, V-3d, and Cr-3d orbitals at the Fermi level is quite more than other TM atoms, leading to a more metallic character of Ta₇TiN₈, Ta₇VN₈, and Ta₇CrN₈.

Nickel sulfate, sodium hypophosphite, sodium tungstate, and sodium molybdate were used as raw materials to synthesize Ni-P-W-Mo hydrogen evolution electrode on nickel foam by one-step galvanostatic electrodeposition method. The surface morphology, elemental composition, and electrochemical hydrogen evolution properties of the materials were investigated by means of X-ray diffraction, SEM, Energy X-ray spectrometry, X-ray photoelectron spectroscopy and electrochemical testing. The results show that Ni-P-W-Mo electrode has excellent catalytic activity and stability after catalyzed hydrogen evolution in alkaline solution. The current density of 10 mA/cm² can be reached only at 92 mV over potential, which is 67 mV lower than that of Ni-P electrode. The double-layer capacitance of Ni-P-W-Mo electrode is 42.98 mF/cm². After 2000 cyclic voltammetry cycles, the hydrogen evolution activity of the electrode decreases only slightly. The excellent catalytic performance of Ni-P-W-Mo electrode may be due to the addition of W and Mo elements to the Ni-P electrode which makes the electrode surface coarser, greatly increasing the electrochemical active surface area and active site of the electrode. Meanwhile, the self-supported electrode structure can effectively reduce the interfacial transmission resistance and improve the charge transmission efficiency.

In-situ loaded two kinds of precursors MOF(denoted as Zn-MOF-74 and ZIF-8) on the surface of carbon paper (CP) were successfully prepared by solvothermal method. After high temperature heat treatment, the precursors were derived into nitrogen-doped porous carbon, and the nitrogen-doped porous carbon @CP electrocatalyst material samples were obtained, named CP-Zn-MOF-74-900-N₂ and CP-ZIF-8-900-N₂, respectively. The effects of CP composition, pore structure and magnetic field intensity on OER(oxygen evolution reaction) were investigated. The results show that the in-situ loaded ZIF-8 forms a dense layer of rectangular dodecahedral particles on the fiber surface of CP, and forms a uniform nanoscale nitrogen-doped carbon material on the fiber surface after heat treatment. ZIF-8-900-N₂ has a specific surface area of 1559 m²/g, pore size of 0.57 nm and pore volume of 1.59 cm³/g, which has the best magnetic properties and magneto-heating properties. CP-ZIF-8-900-N₂ achieves a lowest OER overpotential of 334 mV(current density of 10 mA/cm², iR-corrected) and Tafel slope of 187 mV/dec among carbon paper and nitrogen-doped porous carbon @CP materials. When the external magnetic field exists, the OER overpotential of the catalyst first decreases and then remains unchanged with the increase of magnetic field intensity. And CP-ZIF-8-900-N₂ obtains the lowest overpotential of 316 mV (current density is 10 mA/cm², non-iR-corrected) under a magnetic field intensity of 5.54×10^-3 T, which is 20.4% lower than that without AC magnetic field. This is mainly due to the reduction of bubble size and the enhancement of bubble coalescence caused by the magneto hydrodynamic effect, which improves the desorption of bubbles from the electrode surface.

B₂O₃-Al₂O₃-SiO₂-Sm₂O₃-xCeO₂ (x is 0-6%, molar fraction) glasses were prepared by solid-phase melting method with Sm³⁺/Ce³⁺ co-doping in boron-aluminosilicate glasses (composition 43B₂O₃-25Al₂O₃-32SiO₂) with the help of X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV-Vis-NIR spectrophotometer (UV-VIS-NIR) and other characterization methods to study the structure and laser absorption properties of the glasses. The results show that all samples are glassy with uniform distribution of Sm³⁺ and Ce³⁺. The percentage of bridging oxygen in the glasses increases from 60.12% to 63.82% with the CeO₂ molar fraction increasing from 0 to 2%, and decreases to 59.41% when the CeO₂ molar fraction increases to 6%. The laser absorption performance of the glasses is best at 2%CeO₂ molar fraction, with the diffuse absorption peak at 1 076 nm and the diffuse reflectance of 48.10%. The Sm³⁺/Ce³⁺ co-doped boron-aluminosilicate glass is a promising material for laser absorption at 1.06 μm wavelength.

For spinel LiMn₂O₄ doped with Ni, Co and Al, the first-principles calculations method based on density functional theory is used to analyze the magnetic configuration of the anti ferromagnetic layer and the ferromagnetic layer alternately arranged along the [001] direction rationality. The result show that this magnetic structure shows the valence distribution of Mn³⁺/Mn⁴⁺ alternately arranged along the [001] direction. The doping calculation shows that all three kinds of atoms tend to replace Mn in the Mn³⁺ layer, and the valence states of doped atoms are Ni²⁺, Co³⁺ and Al³⁺ after occupying the 16d site. Al and Ni doping can inhibit the Jahn-Teller distortion of doping sites, and its nearest neighbor Mn³⁺ is oxidized to Mn⁴⁺ after Ni doping, which is more conducive to the stability of the structure. Co doping may result in more severe Jahn-Teller aberrations. The Al³⁺and Co³⁺can significantly reduce the diffusion energy barrier of Li ion in two paths, and Ni²⁺ further reduce the low energy barrier path’s energy barrier under the synergistic action of Mn⁴⁺.