In this study, titanium dioxide (TiO 2 ) nanoparticles were synthesized via a sol-gel method and immobilized onto humic acid (HA) extracted from leonardite to enhance their photocatalytic efficiency under both UV and visible light. The nanomaterial containing 0.03 g of HA (per 0.1 g TiO 2 ) exhibited the highest performance, achieving a degradation efficiency of 99.36% for Methyl Orange (MO) under UV irradiation within 25 min and 98.43% under visible light within 180 min. The apparent reaction rate constant (k) of the optimized TiO 2 /HA nanomaterial reached 1.3252 min −1 under UV irradiation and 0.0957 min −1 under visible light. These values are approximately 39.3 and 15.4 times higher, respectively, than those of pure TiO 2 , indicating a substantial enhancement in catalytic activity.

The Ti-6Al-4V alloy is widely used in the aerospace industry due to its excellent mechanical properties and corrosion resistance. However, its limited wear resistance limits its service life. To address this issue, depositing a CuNiIn coating on the surface of the Ti-6Al-4V alloy has been proposed as an effective strategy. In this study, the CuNiIn coating was prepared by supersonic plasma spraying. The influence of the flight and deposition morphology of different particle sizes on the microstructure of the coating was systematically investigated. At the same time, the effect of friction parameters on the wear mechanism of the coating was studied. The microstructure of the coating was analyzed using scanning electron microscopy and X-ray diffraction. The Vickers hardness tester measured the micro-hardness of the coating. Additionally, the evolution of wear morphology and damage mechanism under different loads was investigated. The results show that as the particle size of the CuNiIn powder increases, the flight speed and temperature of the particles gradually decrease. Due to the increasingly prominent unmelted particle morphology on the coating surface, the surface roughness of the coating increases from 4.3 μm to 18.6 μm. Medium-sized particle powders have better deposition morphology, with the lowest porosity of the coating being 2.62%. Coatings with higher density have the optimal hardness and elastic modulus of 163.1 HV and 122.8 GPa, respectively. When the load increases to 20 N, the dominant wear mechanism shifts from abrasive and oxidative wear to a combined wear mechanism of abrasive, adhesive, and oxidative wear. This study provides a theoretical basis for the application of enhanced CuNiIn coatings.

High-entropy alloys (HEAs), exemplified by the AlCoCrFeNi system, have garnered significant interest in materials science owing to their superior mechanical properties, including exceptional strength and hardness, characteristics that render them particularly well suited for wear-resistant applications. Recent developments have demonstrated that the incorporation of ceramic reinforcement phases into AlCoCrFeNi-based matrices represents an effective strategy for enhancing tribological performance via composite coating architectures. This review offers a comprehensive examination of coating systems, including reinforcement phase selection criteria and matrix functionality. A systematic analysis of matrix-strengthening approaches is provided, elucidating fundamental mechanisms and detailing how variations in alloying elements drive microstructural evolution and consequent improvements in wear resistance. Particular attention is devoted to interfacial optimization, offering a detailed discussion of interface characteristics and optimization strategies achieved through adjustments in elemental composition. Finally, the present limitations of AlCoCrFeNi composite coatings are reviewed, and prospective research avenues are suggested.

The effects of V addition on the microstructure and compression properties of NiAl-Cr alloys were investigated. V does not change the constituent phases but significantly changes the microstructure morphology. With increasing V content, the microstructures change to be Cr(V) dendrites and NiAl + Cr(V) eutectic. V addition markedly enhances the compression strength due to solid solution strengthening and second phase strengthening. At room-temperature, weak interfacial bonding between Cr(V) dendrites and eutectic as well as the deterioration of eutectic microstructure degrade properties. The room-temperature compression strength initially rise and thereafter decline. The NiAl-28Cr-10V alloy has the highest compression strength of 2350 MPa. At high-temperature, microstructural roughening improves strength, leading to the highest compression strength of 411 MPa in NiAl-28Cr-18V alloy.

Fe-Al coatings were deposited on gray cast iron by cold spraying as an exploratory approach for protecting iron relics. The microstructure, deposition efficiency, corrosion property and wear performance of coatings were investigated. Fe-Al coatings completely retained the original composition of mixed powders. Fe particles were surrounded by highly deformed Al particles, and the Fe-50Al coating achieved the highest deposition efficiency (58.6%) and thickness (1.86 mm). Electrochemical tests revealed that the Fe-50Al coating exhibited superior corrosion resistance. Friction and wear tests showed the Fe-50Al coating had the lowest average COF (0.15) owing to its low porosity and distributed soft Al phases. With increasing Al content, the dominant wear mechanism shifted from adhesive to abrasive wear, with oxidative wear present in all coatings.

The intergranular corrosion (IGC) and pitting corrosion behavior of selective laser melted (SLMed) 316L stainless steel (316L SS) after sensitization were systematically investigated and compared with its wrought counterpart. The results reveal that SLMed 316L SS exhibits inferior IGC resistance compared with the wrought material due to its lower proportion of Σ3 coincident-site lattice (CSL) boundaries. However, it shows significantly higher pitting corrosion resistance, which is attributed to the refinement of non-metallic inclusions. Following sensitization treatment, both materials experienced a significant reduction in pitting resistance alongside an increase in metastable pitting events. The underlying degradation mechanisms are elucidated through the analysis of preferential initiation sites and passive film composition evolution.

To evaluate the hot deformation behavior of Al 0.6 CoCrFeNi high entropy alloy, the elevated temperature compression tests were performed. The flow stress decreased as the temperature increased and the strain rate decreased. The shape of the flow curves exhibits that the alloy was undergone the dynamic restoration behavior. The constitutive relationships and processing maps were established, and the optimal hot working condition of 950 °C and 10 s −1 was confirmed through the correlation of temperature-strain rate-strain rate. Deformed microstructure through EBSD analysis revealed that the discontinuous dynamic recrystallization acts as the main dynamic restoration mechanism of the alloy.

Streaky mark defects on hot dip galvannealed Ti-IF sheets were analyzed using SEM, EBSD, FIB, and TEM. Results revealed that bright streak had slightly larger skin-passed area in correspondence to more uniform GA coating. After the removal of GA coating, more coarse grains on the substrate surface, primarily elongated grains along the rolling direction with the normal direction//<100>, were found in the bright streak area. These coarse grains accelerate the Fe-Zn diffusion reaction during galvannealing and result in a flatter coating surface and an even coating thickness. The source of these coarse grains at the uppermost surface could be traced back to the hot rolling.

This study investigates the fabrication and characterization of carbon steel-stainless steel (CS/SS) composite plates using a liquid-solid composite casting process. A 100 × 100 mm laminated composite plate was produced by infiltrating molten stainless steel into a preheated carbon steel substrate. Microstructural analysis, including electron probe microanalysis (EMPA), revealed a well-bonded interface with a smooth transition layer, confirming effective metallurgical bonding between the two steels. The influence of key process parameters—casting temperature (1550–1650 °C), preheating temperature (300–700 °C), and liquid-solid ratio (3:1–5:1)—on mechanical properties, including hardness, shear strength, and plasticity, was evaluated. Higher temperatures and optimal ratios improved interfacial strength and fracture behavior, transitioning from brittle to ductile. Simulation of the casting process illustrated the temperature distribution and interfacial heat transfer, supporting the experimental results. The study concludes that liquid-solid composite casting is a viable method for producing CS/SS composites with superior interfacial properties, making it a promising approach for applications demanding high performance and durability.