Surface Technology (表面技术)•2026•DOI: 10.16490/j.cnki.issn.1001-3660.2026.11.002
Silicon carbide mechanical seal rings in marine rotary equipment suffer severe wear, demanding coatings that simultaneously deliver high hardness, low friction, and corrosion resistance. This study fabricates diamond/diamond-like carbon (DLC) duplex coatings via hot-filament chemical vapor deposition (HFCVD) followed by magnetron-sputter-assisted ion-beam deposition. Microcrystalline diamond (MCD) and ultra-nanocrystalline diamond (UNCD) underlayers are grown on SiC, then capped with a hydrogenated DLC lubricating topcoat, forming a rigid-underlayer/lubricating-top-layer architecture. Tribological tests in simulated seawater reveal that DLC reduces MCD surface roughness from 155.33 nm to 123.77 nm and UNCD roughness from 92.43 nm to 81.90 nm. The MCD/DLC coating lowers steady-state friction coefficient and specific wear rate by 32.08% and 12.22%, respectively; UNCD/DLC achieves 26.67% and 20.92% improvements. SEM, Raman, and XPS analyses of worn surfaces indicate that the DLC top layer mitigates interfacial shear stress, enhances boundary lubrication, and accelerates friction-induced graphitization. The composite coating also reduces counterface ball damage and debris accumulation, extending the service life of mating components. These findings demonstrate that the duplex architecture overcomes the inherent limitations of monolithic diamond coatings, offering a viable route for durable marine seal applications.
New Carbon Materials (新型炭材料)•2025•DOI: 10.1016/S1872-5805(NCM2026-41-03-10)
The surface reconstruction of NiFe-based layered double hydroxide (LDH) electrocatalysts has been widely studied. The reconstructed NiOOH phase plays a critical role in improving the oxygen evolution reaction (OER) performance of NiFe-based LDHs, but observing the NiOOH phase is difficult because of its instability and exploring the functional mechanism of NiOOH in NiFe-based LDHs remains a great challenge. A simple electrochemical activation was used to synthesize a NiOOH/NiFeV-LDH@CC catalyst consisting of an array of V-doped NiFe-LDH nanosheets on carbon cloth (CC), in which the reconstructed NiOOH phase is the active species. During electrochemical activation, the release of doped V leads to the formation of abundant vanadium vacancy (VV) and oxygen vacancy (VO) species, and thus the surface of the NiFe-LDH nanosheets is reconstructed to form NiOOH. Because of the improved intrinsic activity from the NiOOH active phase, and the increased electrical conductivity produced by the abundant VO, NiOOH/NiFeV-LDH@CC has an excellent OER performance in an alkaline solution, with low overpotentials of 209 mV and 241 mV at 20 mA cm−2 and 100 mA cm−2, respectively. It also has a long-term stability of 80,000 s at a constant current density of 10 mA cm−2. Using NiOOH/NiFeV-LDH@CC as the anode, an assembled over water splitting (OWS) battery can drive a current density of 20 mA cm−2 (without iR compensation) at a much lower voltage of 1.597 V. At the same time, the electrolytic cell can deliver a current density of 10 mA cm−2 at ~1.55V for more than 80,000 s without significant loss. This electrochemical activation method can be used in future designs of electrocatalysts for OER.
Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)•2025•DOI: 10.1007/s12613-024-2983-8
The evolution of the microstructure and mechanical properties of WE43 magnesium alloy during multipass hot rolling was investigated. Results revealed that multipass hot rolling promoted the formation of small second phases, which was conducive to multiple dynamic recrystallization, consequently improving the microstructure homogeneity and refining the average grain size from 34.3 μm in the initial material to 8.83 μm. Meanwhile, the rolling deformation rotated abundant c-axis of the grains in the normal direction, resulting in a strong fiber texture. The yield strength in the rolling direction (RD) was improved from 164 MPa in the initial material to 324 MPa in the Pass 3 sheet due to fine-grained strengthening, second-phase strengthening, and texture modification. In addition, the distribution maps of the deformation mechanism indicated that the yield strength anisotropy between the RD and the transverse direction (TD) can be attributed to the effects of the texture component on the dominant mechanism. The dominant deformation mechanism during the tensile test was the prismatic slip caused by the strong basal texture of the RD, whereas it had a lesser proportion of prismatic slip under the influence of the weak basal texture of the TD. Compared to the basal slip, the higher critical resolved shear stress of the prismatic slip resulted in a higher increase in yield strength along the RD at approximately 51 MPa than that along the TD (RD: increase of 160 MPa; TD: increase of 109 MPa).