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The V2O5 nanorods based on carbon spheres (VOR@CSs) were successfully fabricated via anchoring the VOR architecture onto the surface of CSs with hydrothermal and chemical impregnation treatment. The agglomeration of VOR can be decreased due to the CSs being the core of the growth of VOR materials, which effectively support the VOR and expose more reaction active sites. Meanwhile, the CSs can be used as a conductive carbon to significantly enhance the electrical conductivity of composites. Consequently, the VOR@CSs material with special hierarchical structure exhibits a preeminent electrochemical performance; it demonstrates an excellent initial specific discharge capacity of 270 mA h g–1 (coulombic efficiency approach to 100.0%), which is far superior to the VOR for 160 mA h g–1. In addition, more than 82.9% capacitance of the VOR@CSs can be retained after 50 cycles, comparing only 58.1% capacitance retention for VOR. This promising VOR@CSs composite modified from VOR has significantly promoted the application in the practical production of developing high-performance lithium-ion batteries. [ABSTRACT FROM AUTHOR]

In the present work, the MoN-MoSx composite coatings were prepared by reactive sputtering of Mo and MoS2 targets. The influence of MoS2 target power on the structure, morphology and mechanical properties of composite coatings was investigated, and the tribological properties of coatings were evaluated under PAO6 base oil lubrication. As the increase of MoS2 target power was from 0 to 1000 W, the highest coating hardness and the optimized tribological performances were achieved at 400 W. Different from pure MoN coating, it was observed that MoN-MoSx composite coatings exhibited a time-dependent friction behavior, the friction coefficients and wear rates slowly decreased with the extension of sliding time. As the sliding test lasted for 4 h, the MoN-MoSx coating with the highest hardness gave a lower friction coefficient (~ 0.06) and significantly higher wear resistance (1.1 × 10−9mm3/N·m). Worn surface analysis indicated that a tribofilm containing MoS2, Mo oxides, and sulfates on steel ball could be associated with the excellent friction and wear properties of MoN-MoSx coating solid–liquid composite lubrication. As a result, it can be concluded that such MoN-MoSx coating offers a new candidate for tribological engineering toward future green and high-performance applications. [ABSTRACT FROM AUTHOR]

To explore the influence of surface quality on gear scuffing performance, an experimental investigation is performed on gears treated with different surface techniques using an FZG-type test rig. Scuffing loading capacity and detailed failure modes of gears with different surface technologies are discussed. Results reveal that the scuffing limiting temperature of the baseline ground gear under 50% surviving probability is 228.8 °C. The diamond-like carbon (DLC) coating greatly enhances gear scuffing performance, and the scuffing limiting temperature increases by 17.3% compared with the ground baseline. Under 99% surviving probability, the scuffing limiting temperature differences between ground, shot-peened, and superfinished gears are within 1.2%. This experimental investigation provides support for antiscuffing design of modern high-speed gear transmissions. [ABSTRACT FROM AUTHOR]

Ni–Co–P/Si3N4 composite coatings were fabricated over an aluminum–silicon (Al–Si) substrate using a pulse-current electroplating process, in which the rapid deposition of an intermediate nickel–cobalt layer was used to improve coating adhesion. The microstructure, mechanical, and tribological behaviors of the electroplated Ni–Co–P/Si3N4 composite coating were characterized and evaluated. The results revealed that the electroplated Ni–Co–P/Si3N4 composite coating primarily consisted of highly crystalline Ni–Co sosoloid and P, and a volumetric concentration of 7.65% Si3N4. The electroplated Ni–Co–P/Si3N4 composite coating exhibited hardness values almost two times higher than the uncoated Al–Si substrate, which was comparable to hard chrome coatings. Under lubricated and dry sliding conditions, the electroplated Ni–Co–P/Si3N4 composite coating showed excellent anti-wear performance. Whether dry or lubricated with PAO and engine oil, the composite coating showed minimum abrasive wear compared to the severe adhesive wear and abrasive wear observed in the Al–Si substrate. [ABSTRACT FROM AUTHOR]

Pure MoS 2 coatings are easily affected by oxygen and water vapor to form MoO 3 and H 2 SO 4 which cause a higher friction coefficient and shorter service life. In this work, five kinds of MoS 2 /Ti-MoS 2 /Si multilayer nanocomposite coatings have been deposited by using unbalanced magnetron sputtering with different modulation period ratios. The tribological tests and nano-indentation experiments have been carried out in order to study the tribological and mechanical properties of the multilayer nanocomposite coating. The results show that the hardness and internal stress of the multilayer nanocomposite coatings are superior to those of the pure MoS 2 coating. The polycrystalline columnar structures are effectively inhibited and the coating densification increases due to the multilayer nanostructure and the doped elements of Ti and Si. The nanocomposite coating with a modulation period ratio of 100 : 100 shows the lowest friction coefficient and wear rate. The multilayer nanocomposite coatings exhibit excellent tribological property under a heavy constant load. Interfaces in multilayer nanostructure coating is able to hinder the dislocations motion and the crack propagation. The doped elements of Ti and Si with nano-multilayer structure enhances the mechanical and tribological properties of MoS 2 coating. This study provides guidelines for optimizing the mechanical and tribological properties of MoS 2 coating., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)