Marine components often face severe challenges due to high friction, wear, and corrosion in saline environments. In this work, graphite-like carbon (GLC) films reinforced with nano high-entropy carbide (HEC) layers were designed to enhance durability. The insertion of nano HEC layers intensified the bias-induced etching effect, increasing the sp3 bonding fraction and improving hardness. Meanwhile, interfacial passivation developed each HEC layer effectively slowed the diffusion of corrosive ions. As a result, the multilayer architecture provided superior electrochemical stability and tribo-corrosion resistance. Notably, the optimized eight-period (HEC/ GLC)8 multilayer film exhibited excellent corrosion resistance, with the corrosion current density reduced 4.51 & times; 10-8 A/cm2. It also maintained structural integrity under tribo-corrosion tests and achieved an ultralow friction coefficient of 0.03.

To enhance the service stability of cemented carbides in marine and other corrosion-wear coupled environments, a series of Si-DLC coatings was fabricated via magnetron sputtering by adjusting the acetylene flow rate. The chemical structure, mechanical properties, and electrochemical and tribocorrosion behaviors in 3.5 wt% NaCl solution were systematically evaluated. The results showed that an acetylene flow rate of 8 sccm enabled optimal silicon incorporation, enhancing the H/E* and H3/E*2 ratios, reducing residual stress and porosity, resulting in a denser structure with the highest pore resistance (1.0 x 107 Omega & sdot;cm2) and lowest corrosion current density (2.0 x 10_8 A/cm2). This condition also resulted in excellent wear resistance and a minimum coefficient of friction of 0.09. SXAS further revealed the evolution of coating porosity, confirming that the sample deposited at 8 sccm acetylene exhibited the lowest porosity and the most uniform pore size distribution. By contrast, although the coating deposited at 10 sccm showed the highest hardness, its tribocorrosion performance declined due to pore agglomeration and increased residual stress.

To improve the durability of cemented carbides in corrosion-wear coupled environments, a series of Cr/Si co-doped DLC coatings was deposited by magnetron sputtering, in which the Si content was maintained while the Cr content was systematically varied. The results reveal a pronounced structure-property correlation governed by Cr incorporation. With increasing Cr content, the coating evolves from a dense, homogeneous amorphous structure to a heterogeneous, nanocomposite-like structure with higher nanocluster density and defect connectivity. At moderate Cr content, the coating exhibits optimal performance, characterized by a high coating resistance (3.8 × 105 Ω·cm2), low corrosion current density (1.6 × 10-7 A/cm2), low friction coefficient (0.101), and minimum wear rate (2.5 × 10-7 mm3/N·m). This behavior is attributed to the formation of Cr-C bonds and a more compact structure, which effectively suppresses defect connectivity and inhibits electrolyte penetration, resulting in barrier-controlled corrosion. In contrast, excessive Cr induces structural heterogeneity and the formation of defect-connected pathways, promoting electrolyte transport and accelerating degradation. Consequently, the corrosion mechanism transitions from barrier-controlled to transport-dominated behavior, while the tribocorrosion failure evolves from mild wear to severe delamination due to the synergistic coupling between corrosion and mechanical damage.

Tribocorrosion is a common and highly challenging service condition for marine engineering equipment, and improving the durability of cemented carbides in corrosion-wear coupled environments is of great significance. In this study, a-C:H(Si, Cr) coatings were prepared by dual-target magnetron sputtering, and their tribological behavior was investigated. The a-C:H(Si, Cr) film with a Cr concentration of 7 at.% exhibited excellent lubricating behavior, with a coefficient of friction of 0.1. Compared with the a-C:H(Si, Cr) film containing 12 at.% Cr, its wear rate was reduced by 90%, mainly due to the microstructural changes induced by Cr incorporation. The results show that Cr incorporation promotes the formation of ordered sp2-C clusters in the a-C:H(Si, Cr) film, which is beneficial for constructing a more ordered carbon network. The Cr-mediated carbon network reconstruction and the formation of Cr-C bonds help release internal stress, enhance film-substrate adhesion, and promote the formation of a stable transfer film. During corrosive sliding, the synergistic effect of stable interfacial bonding and the transfer film reduces mechanical shear damage and restricts electrolyte penetration along defect channels toward the coating/substrate interface, thereby weakening the coupled failure between corrosion and wear. This mechanism links atomic-scale bonding and interfacial stability with macroscopic tribocorrosion performance, highlighting a-C:H(Si,Cr) films as promising corrosion-resistant lubricating coatings.

This study focuses on rhenium nitride (ReNx) coatings (x = 0.37-0.50) deposited on YG8 cemented carbide via magnetron sputtering, investigating nitrogen content's regulation of their microstructural evolution and comprehensive properties. By adjusting the N2/Ar flow ratio (S1:1:1 to S4:1:4), coatings with varying nitrogen contents were prepared. Characterizations via X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nanoindentation, tribological/ electrochemical tests, and first-principles calculations confirm all coatings exhibit a face-centered cubic (fcc) ReNx phase. High nitrogen (S1, x = 0.50) promotes dense, low-roughness (Sa (surface roughness parameter) =1.43 nm) microstructures via lattice contraction and strong Re-N bonding; low nitrogen (S4, x = 0.37) causes metallic Re accumulation, increasing roughness (Sa = 1.75 nm) and deposition rate. Mechanically, hardness peaks at 27.66 GPa for S3 (x = 0.40)-supported by TEM observations of dense columnar grains, dislocation walls, and refined grains (19.7 nm)-while elastic modulus rises from 537.0 GPa (S1) to 589.5 GPa (S4) with decreasing nitrogen. Tribologically, minimum friction coefficient (0.1) and wear rate (9.0 x 10-8 mm3/(N & sdot;m), S2) come from tribo-induced ReO2/ReO3 lubricants and dense structure. Electrochemically, S1 shows corrosion current density (1.93 x 10-6 A/cm2) two orders lower than YG8 (2.23 x 10-4 A/cm2) due to the dense structure's barrier effect. This work clarifies nitrogen-driven structure-property relationships of ReNx coatings, supporting their optimization for friction-corrosion coupled extreme environments.

Diamond-like carbon (DLC) films are regarded as highly competitive surface films for marine service environments owing to their excellent lubricity, wear resistance, and corrosion protection. In this work, a series of (NbTaMoWAl)(x)-DLC films were developed by systematically tuning the multi-element co-doping levels. We investigated its effects on microstructural evolution and tribo-corrosion mechanisms. At low doping levels ( similar to 4 at%), multi-element additions promoted the formation of a stable carbonate-type passive film and preserved high compactness with the sp(3) carbon network, thereby increasing the charge transfer resistance (R-ct), lowering the friction coefficient, and suppressing the tribo-corrosion failure. With further enrichment in multi-element content (similar to 12, 24, 35 at%), the films exhibited intrinsic features of carbide ceramics: increased columnar gaps and grain-boundary channels and stronger interfacial galvanic effects. It led to the OCP shifting toward more negative values, and the COF showed larger fluctuations. Such microstructural evolution caused by excessive multi-element doping accelerated the penetration of corrosive media along columnar grain boundaries and channels, thereby undermining the overall protective efficacy.

Silicon carbide (SiC) exhibits exceptional hardness and brittleness that severely limit machining efficiency and surface quality. This work reports, for the first time, the electro-plastic softening of single-crystal SiC under direct current fields and proposes a novel mechanism: the effect originates synergistically from radial electric fields generated by surface charge accumulation and electron wind forces. Indentation experiments demonstrate current-dependent hardness reductions governed by surface treatment, electrode geometry, sample dimensions, loading rate, and applied load. Moreover, the reduction in hardness exhibits a clear correlation with the distribution of surface charge density. Furthermore, this study provides the quantitative calculations of surface and space charge densities distributions near the semiconductor surface under direct current fields, establishing theoretical foundations for predicting internal current intensity and radial electric field strength across material systems. Results reveal a critical doping-dependent transition. First-principles calculations establish that the radial electric field reduces the bandgap, thereby lowering dislocation nucleation energy barriers and facilitating plastic deformation. Besides, the effect intensity is inversely proportional to doping concentration and directly proportional to current density. This work provides both experimental evidence and theoretical insight for achieving efficient and high-quality machining of SiC through current-field-assisted methods.

Transparent glass composites with high crystallinity (HC-TGC) exhibit significant potential for applications in nonlinear optics, solid-state laser systems, and optical information processing technologies. However, achieving HC-TGC is often hindered by the substantial refractive index mismatch between functional crystals and the glass matrix. To address this challenge, we propose an in situ refractive index buffering strategy. Using LiTaO3 as a prototype TGC, we controlled the precipitation of a secondary LiAlSi2O6 crystalline phase, which was found to markedly enhance optical transparency. Both the theoretical and experimental analyses reveal that this secondary phase acts as a "refractive index buffer", effectively reducing the refractive index contrast (Delta n) between the LiTaO3 nanocrystals and the surrounding glass matrix, thereby minimizing light scattering. As a result, we successfully obtained LiTaO3 TGC with high crystallinity (>85 wt.%) and excellent optical transparency (>70% at 1.5 mm). The composite demonstrates a robust second-harmonic generation (SHG) response, as well as a unique transverse second-harmonic generation (TSHG) effect. Furthermore, utilizing this HC-TGC, we developed a TSHG optical setup and demonstrated its application in monitoring ultrashort optical pulses. This work introduces a generalizable design strategy for creating highly transparent, functional HC-TGCs, paving the way for advancements in integrated nonlinear photonics.

Addressing the environmental challenges posed by persistent organic pollutants, this study explores the electrochemical oxidation of phenazopyridine hydrochloride (PhH) using a boron-doped diamond (BDD) electrode prepared via Hot Filament Chemical Vapor Deposition. A BDD thin film electrode was successfully synthesized on a silicon substrate, demonstrating excellent crystalline quality. Under optimized conditions, PhH was nearly completely degraded within 180 min, following a pseudo-first-order kinetic model and maintaining consistent efficiency across nine cyclic processes. Radical quenching experiments identified hydroxyl radicals (center dot OH) as the primary oxidative species. High-Performance Liquid Chromatography-Mass Spectrometry and Density Functional Theory calculations revealed two primary degradation pathways. Quantitative Structure-Activity Relationship models predicted significant reductions in toxicity, including acute toxicity, chronic toxicity, Ames mutagenicity, and developmental toxicity. This research offers a promising approach for environmental pollution remediation by providing critical insights into the electrochemical degradation of PhH.

Femtosecond mode-locked lasers (MLLs) with hundreds of megahertz repetition rate are of broad interest due to the relatively large longitudinal mode interval. The performance of MLL is dominated by the active fiber, and candidates with both high gain and high compatibility with inactive silica fiber are urgently required. Herein, we propose and demonstrate an Er-doped hybridized silicate glass fiber (EHSGF) for nonlinear polarization rotation-based high-repetition-rate MLL. The fiber is derived from silica and hybridized with Y and Al elements, which enables providing a rich chemical environment for the active Er dopant. As a result, EHSGF with heavily doped Er3+ ions and a high gain coefficient of 2 dB/cm can be realized. In addition, it exhibits excellent chemical affinity with the Si-O, and the fiber can be directly fused with commercial silica fiber without a bridge component. We design and build a stable MLL device with a fundamental repetition rate up to 318.94 MHz by using only 9.5 cm EHSGF without any special integrated devices. The central wavelength is around 1565 nm with a 3 dB width of 32 nm, and the direct output pulse duration is 87 fs, which is close to the transform limit. The measured root mean square power fluctuation remains below 0.039% during continuous 12-h operation. We believe this research provides a new strategy for the development of highly doped Er-doped fibers and high-repetition-rate laser systems.

In order to obtain the better tribological properties of high entropy carbides, five elements, including Nb, Ta, Mo, W, and Al, were selected as candidate elements. Machine learning was used to design and choose the optimal component ratio of NbTaMoWAlC coating. The NbTaMoWAlC coating with a hardness of 28.5 GPa was fabricated by pulsed DC magnetron sputtering. An appropriate concentration of Al could refine the grains, enhance atomic size differences, deepen lattice distortion, and reinforce the solid solution effect. The NbTaMoWAlC coating had a lower coefficient and wear rate than NbTaMoWC coating. These findings contributed to developing HEC with enhanced mechanical properties for the application field of wear-resistant parts.

High-entropy alloys (HEAs) have attracted much attention due to their excellent corrosion resistance. The corrosion resistance of HEAs varies significantly across different aqueous environments, influenced by the complexity of service conditions, chemical interactions, and heat treatment processes. Extensive trial-and-error strategies have resulted in high costs and constrained the development of novel HEAs. This study proposes a machine learning (ML)-based model for predicting corrosion resistance, aiming to support the rational design of HEAs tailored for specific environments. Based on material informatics, to achieve the best prediction results, we need the best combination of models and features. Hyperparameter searching is performed on six different ML models and a three-step feature reduction strategy is proposed, which further improves the prediction accuracy and generalization capability relative to the traditional recursive elimination (RFE) method. Based on the best-performing eXtreme gradient boosting (XGBoost) model, 14 key descriptor factors affecting the corrosion resistance of HEAs, such as the average melting point (Tm), PH level (PH), halide ion concentration (Hal. Molar.), annealing temperature (Anneal_T), and valence electron concentration (VEC), were identified. Additionally, the corrosion resistance properties of non-equimolar quinary HEAs were analyzed from the elemental point of view using ternary contour phase diagrams; the SHapley additive interpretation (SHAP) method was employed to establish comprehensive design principles for the development of novel corrosion-resistant high-entropy alloys, with particular emphasis on structural considerations.

Significance Ultrashort pulse lasers, characterized by pulse durations of less than 1 ps and peak power densities exceeding 109W/cm2, are indispensable in various domains, including attosecond science, laser fusion, ultrafast photonics, precision machining, and biomedicine, due to their ultrafast temporal characteristics. Nonetheless, accurately measuring their fundamental parameters, such as pulse duration and phase, presents considerable challenges. Traditional electronic measurement techniques are limited by their picosecond-level time resolution, rendering them inadequate for assessing sub-picosecond pulses. Nonlinear detection methods, which utilize optical autocorrelation to translate time-domain information into spatial or spectral domains via frequency doubling or summation effects in materials, have emerged as pivotal in overcoming these measurement limitations. The efficacy of nonlinear optical materials, which serve as the fundamental media for this technology, is critical, as their properties including phase matching capability, response bandwidth, and signal strength directly influence detection accuracy, sensitivity, and applicability. Consequently, the advancement of high-performance bulk optical materials is of paramount importance for fostering progress in ultrafast science and its industrial applications. Progress This paper provides an overview of the nonlinear optical response characteristics of two kinds of prevalent bulk optical materials utilized in the detection of ultrashort laser pulses: crystalline and glass materials. It also highlights recent advancements in the domain of ultrashort laser pulse detection. In the initial section concerning nonlinear crystal materials, it is noted that crystals have emerged as the predominant choice for early ultrashort laser pulse detection, attributed to their superior nonlinear coefficients and the well-established phase-matching techniques. This category is primarily divided into two types: single-domain crystals and multi-domain crystals. Single-domain crystals facilitate efficient frequency doubling via birefringence phase matching, however, they necessitate precise mechanical angle adjustments. O'Shea et al. demonstrated the use of a 1 mm thick BaB2O4 (BBO) crystal in conjunction with angular scanning to achieve synchronous time-domain and phase measurements, achieving an accuracy comparable to that of 100 mu m thick KH2PO4 (KDP), albeit with limited anti-vibration capabilities. Multi-domain crystals encompass periodically polarized crystals, which enhance conversion efficiency through quasi-phase matching (QPM) but exhibit a relatively narrow bandwidth. Miao et al. introduced a design for an aperiodic domain structure that significantly broadens the bandwidth by a factor of 100, enabling high-precision pulse measurements at ultra-low energy levels ranging from 124 aJ to 9.5 fJ, with sensitivity that is eight orders of magnitude greater than those of single-domain crystals. Additionally, random multi-domain crystals, such as strontium barium niobate (SBN), possess one-dimensional ordered and two-dimensional disordered needle-like ferroelectric domain structures, which provide an infinite array of inverted lattice vectors to mitigate phase mismatch. Fischer and colleagues leveraged the SBN transverse second harmonic generation (TSHG) effect to achieve real-time measurements of individual pulses (ranging from 30 fs to 200 fs) without mechanical scanning, covering a dynamic range from 30 fs to 1 ps and spanning wavelengths from 800 nm to 2200 nm. The subsequent section addresses nonlinear glass materials. Despite their isotropic nature, second-order nonlinearity can be induced through the disruption of local symmetry. In recent years, these materials have garnered significant attention due to their broad response characteristics. The microcrystalline glass composite strategy primarily involves the formation of randomly oriented microcrystals through a crystal-glass composite, facilitating wide-band and wide-angle responses via random quasi-phase matching (RQPM). Researchers in this field have manipulated the nonlinear response of materials through two principal approaches to enable the measurement of ultrashort laser pulses. The first approach involves entropy engineering to control grain size. Feng et al. successfully synthesized high-crystallinity nanocrystalline composite glass (NIG) by adjusting the entropy value of niobium-silicate glass, resulting in a grain size of less than 10 nm in the high-entropy system. This study marked the first observation of a lateral frequency doubling signal under a weak scattering background, achieving pulse measurement within the 870 -1300 nm range (with an error margin of less than 10 fs), while also eliminating the need for mechanical alignment. The second enhancement pertains to the mixed base effect, as demonstrated by Lin et al., who incorporated large-radius alkali metal ions (K+, Rb+, Cs+) to mitigate lattice defects in LiNbO3. This modification resulted in a doubling of the frequency doubling intensity and a blue shift of the absorption edge to 356 nm. Utilizing the NGC-4Cs sample, the measurement bandwidth was extended to 780 -820 nm for the first time, thereby encompassing the operational range of the titanium-sapphire laser. Furthermore, Yan et al. employed the Na+ mixing effect to facilitate real-time monitoring of pulse distortion phenomena, such as splitting and forward tilt, achieving a sensitivity of 600 fs delay and a tilt angle of 10 degrees. Conclusions and Prospects Currently, both nonlinear crystals and glass ceramics possess distinct advantages in the domain of ultrashort pulse detection. Nonlinear crystals are characterized by their high precision, however, their manufacturing processes are intricate and their operational bandwidth is constrained. Conversely, microcrystalline glass offers a broad bandwidth response and does not necessitate mechanical alignment, although there is a need for enhancement in signal strength. Future research endeavors should concentrate on several key areas. Firstly, optimization of material design is essential. This involves the precise control of internal grain size, distribution, and defect concentration within microcrystalline glass to balance scattering loss with nonlinear enhancement effectively. Additionally, the exploration of novel natural multi-domain crystals or artificial metamaterials is crucial for expanding the phase-matching bandwidth. Secondly, the integration and innovation of technology should be prioritized. This includes the implementation of lateral frequency doubling to develop a real-time single-pulse detection system, as well as the incorporation of machine learning algorithms to enhance inversion efficiency. Furthermore, promoting the utilization of microcrystalline glass in integrated photonic chips will facilitate the advancement of miniaturized and multifunctional detection platforms. In summary, the ongoing innovation in nonlinear optical materials is anticipated to propel ultrashort pulse detection towards higher precision, integration, and multifunctionality, thereby presenting new opportunities for ultrafast science and its applications.

Optical fiber communication has greatly promoted the development of the information age, while the emergence of 5G networks, cloud computing, and artificial intelligence have put forward high challenges to the capacity of current optical fiber communication systems. At present, increasing the bandwidth of erbium-doped fiber amplifiers (EDFA) is the most effective way to increase the communication capacity. In this paper, a hybridization strategy is proposed for simultaneous achieving strong and flat optical response and demonstrate the success in construction of Er3+-Tm3+ co-doped gadolinium aluminosilicate glass fiber for L-band optical amplification. Gd3+ ions are introduced to enhance the radiative transition by improving the dispersibility of Er3+. Tm3+ ions are co-introduced to facilitate energy transfer between Er3+ and Tm3+ for achieving flat emission in the L-band. The hybridized active fiber which can be effectively fused with quartz fiber is fabricated by melt-in-tube (MIT) approach. A fiber amplifier is construed and it enables to achieve a flat on-off gain (<+/- 0.76 dB) across the L-band spectrum. These results indicate that Er3+-Tm3+ co-doped hybridized gadolinium aluminosilicate glass fiber is a promising gain material for fiber amplifiers and demonstrate that the hybridization approach provides a new strategy for the development of novel active fiber device.

The rapid developments of technologies create an urgent requirement for increasing the capacity of the optical fiber communication system. The most promising way is to extend the communication wavebands. Here, it is reported that the hybridized Er‐doped active fiber (EDF) and Er‐doped fiber amplifier (EDFA) devices present broadband optical response. The EDF consists of a cross‐linked ‐Si─O‐ and ‐P─O‐ network, which leads to great inhomogeneous broadening and wide net gain from 1575 to 1625 nm. The EDFA devices are constructed by gain‐clamped strategy and broadband amplification is realized. The booster is successfully fabricated with a gain above 25 dB and a flatness below ±0.86 dB from 1575 to 1620 nm at the input signal power between −13 and 0 dBm. The pre‐amplifier has also been constructed with a gain above 20 dB and a flatness around ±0.3 dB at the input signal power from −40 to −25 dBm. Furthermore, the practical application of the hybridized EDFA device for high‐capacity coherent transmission is demonstrated. The results reveal a novel idea to realize gain‐flattened amplification and provide a valuable solution for the new generation of high‐capacity coherent communication systems.

The wear and corrosion of cemented carbides pose substantial challenges to maintaining the reliability and extending the service life of marine engineering equipment under severe maritime conditions. In this study, a self-enhanced magnetron sputtering system combined with a straight-tube filtered cathode vacuum arc deposition system was employed to fabricate tetrahedral amorphous carbon (ta-C) coatings on cemented carbides. Four distinct coatings were prepared using a 70 A direct current power supply and a pulsed direct current power supply with peak currents varying from 300 to 500 A. The results indicate that the application of pulsed current power significantly improves the surface quality of the coatings and increases their sp3 content. As the peak pulse current increases, the energy of C ion bombardment gradually rises, leading to a trend in which the mechanical and physical properties of ta-C coatings initially improve before declining. The coating prepared with a peak current of 400 A exhibits the best wear rate (3.6 x 10-6 mm3 center dot N- 1 center dot m- 1) and the best electrochemical stability (open current potential = -0.3 V), which can be attributed to its superior coating composition (sp3 fraction = 72 %), improved resistance to plastic deformation (H3/E*2 = 0.8 GPa) and fewer coating defects.

LiNbO3 nanocrystal-glass composites (LiNbO3-NGC), characterized by its unique 3D random domain structure, have shown great promise for significant applications, such as femtosecond pulse monitoring and full-color 3D displays. However, the nonlinear response of the LiNbO3-NGC is greatly suppressed by the defects, and effective manipulation of these defects remains a long-standing challenge. In this study, a Na-hybridization strategy is proposed to control defects in the LiNbO3-NGC to enhance its nonlinear properties and realizing its practical application for ultrashort optical pulse monitoring. The findings reveal that the incorporation of Na ions effectively reduces the defects within the composite, resulting in significantly improved nonlinear effects. By using this hybridized LiNbO3-NGC, the transverse second-harmonic generation is achieved. An ultrashort optical pulse system is also constructed and successfully applied it for real-time quantitative measurement of the duration, distribution, and front tilting of optical pulses in the 10-15 s scale. These results not only present an excellent example about defect engineering in nonlinear LiNbO3-NGC but also point to practical applications for the measurement of extreme physical parameters.

Diamond like carbon (DLC) was a potential coating due to its excellent mechanical properties. In this work, we developed a novel method where multi gradient Cr/Cr-WC/WC-DLC/DLC coatings were deposited on Cr12MoV substrates using high-power impulse magnetron sputtering (HiPIMS)/CVD at different rpm (revolutions per minute) ratios (revolution/rotation). The enhancement mechanisms of the tribological properties and electrochemical corrosion performance of the multi gradient DLC coatings were systematically investigated. The results show that the hardness and elastic modulus of the coatings increased with the rise in the rpm ratio, likely due to the increased sp3-C content in the coatings. The rpm ratios tested ranged from 0.1 to 0.5, with the maximum hardness of the DLC coating reaching 24 GPa at an rpm ratio of 0.5. The adhesion of DLC coating is as high as 73N, showing excellent bonding strength. The wear resistance of the DLC coating is linked to its hardness, low friction, strong adhesion, and self-lubrication. The DLC coatings demonstrated excellent tribological properties, with the coating deposited at an rpm ratio of 0.5 showing extremely low wear rates (1.9 x 10-7mm3/N.m). Finally, the coatings exhibited higher corrosion potentials and lower corrosion current densities with increasing rpm ratios. The multi gradient DLC coatings with an rpm ratio of 0.5 showed the best corrosion resistance.

Due to the characteristics of low-temperature brittle conversion of metal molybdenum, it will affect its performance under high-temperature conditions. This paper first established a computational model for the solid/liquid/gas three-phase system to analyze material removal characteristics, temperature fields, and recast layer dimensions of Molybdenum metal induced by laser processing and laser water-assisted processing. Then a processing experimental platform was constructed, and the microstructure, organization, and elemental content of the laser-processed edges were tested using SEM, micro-XRD, and EDS techniques. The results indicate that the novel water-assisted laser processing method can accelerate the cooling rate of the laser-affected surface and suppress the formation of recast layers at the cutting boundary. Additionally, water can isolate the interaction between oxygen in the air and molybdenum, effectively reducing the generation of molybdenum dioxide. However, when water is excited by the laser, it can produce a large number of ionized electrons, leading to the deposition of particulate products on the metal surface. The findings of this study provide a theoretical basis for efficient and high-quality processing of difficult-to-machine metal materials. Laser water-assisted processing can be used as a new processing method for hard and brittle materials.