Surface & Coatings Technology最新文献

{"title":"Thermal stability, oxidation resistance, and mechanical properties of CVD TiB0.19C0.37N0.44 hard coating","authors":"Fangfang Zeng ,&nbsp;Lianchang Qiu ,&nbsp;Liying Wu ,&nbsp;Jifei Zhu ,&nbsp;Wei Cheng ,&nbsp;Jin Wen ,&nbsp;Yong Du ,&nbsp;Xiaoshan Zeng","doi":"10.1016/j.surfcoat.2026.133226","DOIUrl":"10.1016/j.surfcoat.2026.133226","url":null,"abstract":"<div><div>Nanocomposite TiBCN coatings are promising advanced materials owing to their high hardness, wear resistance, and corrosion resistance. This study investigated the thermal stability and oxidation resistance of a TiB_0.19C_0.37N_0.44 coating deposited on WC-Co cemented carbide by chemical vapor deposition (CVD). The as-deposited TiB_0.19C_0.37N_0.44 coating consisted of nanocrystalline Ti(C,N) and Ti(B,C) phases embedded in an amorphous CN/BN matrix. The incorporation of B atoms into the TiCN coating induced the formation of stacking faults, and the hardness of the TiB_0.19C_0.37N_0.44 coating reached 39.1 GPa. The coating maintained its original phase structure after vacuum annealing at temperatures up to 1200 °C. At 1300 °C, B atoms reacted with the WC-Co substrate to form the CoWB phase. With increasing vacuum annealing temperature, the coating hardness decreased continuously. This behavior is attributed to stress release, grain coarsening, B atom diffusion, and degradation of the nanocomposite structure. During oxidation, the coating exhibited a relatively slow oxidation rate at 600–700 °C. However, after oxidation at 800 °C, the reaction of C and B atoms with oxygen led to the formation and volatilization of CO and B₂O₃, generating pores and microcracks. In summary, the TiB_0.19C_0.37N_0.44 coating maintains a stable phase structure after vacuum annealing below 1300 °C, whereas it undergoes complete oxidation after air annealing at 900 °C. These findings indicate that the TiB_0.19C_0.37N_0.44 coating possesses considerable potential for high-temperature cutting applications.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"523 ","pages":"Article 133226"},"PeriodicalIF":6.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strengthening mechanisms in CoCrFeNiMn high-entropy alloy coatings reinforced by CoNi-coated WC under magnetic field-assisted plasma cladding","authors":"Shuai Li ,&nbsp;Yi Sun ,&nbsp;Liangliang Zhang ,&nbsp;Zhongying Liu","doi":"10.1016/j.surfcoat.2026.133216","DOIUrl":"10.1016/j.surfcoat.2026.133216","url":null,"abstract":"<div><div>High-entropy alloy (HEA) composite coatings reinforced with ceramic particles have emerged as one of the key strategies for preventing friction and wear. In order to improve the wettability between WC particles and HEA powders, CoNi-coated WC particles were introduced into CoCrFeNiMn HEA powders. Subsequently, CoCrFeNiMn/30YGN20 (70 wt% CoCrFeNiMn +30 wt% YGN20 (80 wt% WC, 10 wt% Ni, and 10 wt% Co)) HEA coatings were fabricated on Q235 steel via magnetic field-assisted plasma cladding, and their strengthening mechanisms were systematically investigated. The results indicate that the CoNi-coated WC particles react with the matrix during the cladding process to form the M₃W₃C phase, thereby enhancing the interfacial bonding strength between the reinforcing phase and the matrix. Meanwhile, the electromagnetic braking effect induced by the magnetic field resulted in a more uniform distribution of WC particles. In addition, the thermoelectromagnetic convection generated by the magnetic field refined the grains of both the FCC matrix and the M₃W₃C phase, and promoted the formation of twins within the coating. These mechanisms collectively contributed to a remarkable enhancement of the coating performance through second-phase strengthening, solid-solution strengthening, and grain-boundary strengthening. Consequently, surface hardness increasing from 292.7 HV_0.2 to 365.7 HV_0.2 with the increasing of magnetic field strength. Wear behavior transitioned from dominant oxidative and adhesive wear under low magnetic fields to stable abrasive wear at higher fields, as grain refinement and WC particle participation increased. Under a magnetic field strength of 60 mT, the coating exhibited the best wear resistance with friction coefficients of 0.47.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"523 ","pages":"Article 133216"},"PeriodicalIF":6.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Controlled thermal oxidation of AlCrYTiZr high-entropy alloy for enhanced corrosion resistance and mechanical properties","authors":"Chunyu Wang ,&nbsp;Shu Xiao ,&nbsp;Chunming Wu ,&nbsp;Zishuo Ye ,&nbsp;Hu Zhang ,&nbsp;Wenhao Wang ,&nbsp;Saihua Jiang ,&nbsp;Qingdong Ruan ,&nbsp;Yi Wu ,&nbsp;Paul K. Chu","doi":"10.1016/j.surfcoat.2026.133234","DOIUrl":"10.1016/j.surfcoat.2026.133234","url":null,"abstract":"<div><div>High-entropy alloy (HEA) coatings show great promise for corrosion protection of critical marine component surfaces but are limited by passive film degradation during long-term service in extreme marine environments. In this study, amorphous AlCrYTiZr HEA coatings are deposited on X70 steel by magnetron sputtering and then thermally oxidized at 400 °C for 2, 30, or 60 min to form AlCrYTiZrO_x (x = 31.7, 41.4, or 46.0) coatings. It is observed that extending the thermal oxidation time to 30 min resulted in the formation of a dense oxide layer (∼200 nm thick) on the coating surface, accompanied by oxygen slow diffusion into the coating interior. Furthermore, thermal oxidation enhances the adhesion between the coating and the substrate. The combined action of the surface oxide layer and amorphous coating structure effectively blocks the penetration of the external corrosive medium. As a result, AlCrYTiZrO_41.4 shows a self-corrosion current density of 2.7 × 10⁻⁹ A/cm² and hardness of 17.87 GPa. Compared to the as-deposited AlCrYTiZr HEA coating, the self-corrosion current density of the coating decreases by a factor of 14, while the hardness increases by 2.37 times. The results reveal a concise and efficient strategy for enhancing HEA coating performance, thereby expanding its potential for corrosion protection applications on X70 steel surfaces.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"523 ","pages":"Article 133234"},"PeriodicalIF":6.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fabrication of gradient structure in 7075 aluminum alloy via initial microstructural regulation and synergistic strengthening and toughening mechanism","authors":"Shaolei Long ,&nbsp;Kai Feng ,&nbsp;Ming Yang ,&nbsp;Shengshan Pan ,&nbsp;Jie Dong ,&nbsp;Yu Liang ,&nbsp;Qin Gui ,&nbsp;Yanliang Yi","doi":"10.1016/j.surfcoat.2026.133221","DOIUrl":"10.1016/j.surfcoat.2026.133221","url":null,"abstract":"<div><div>In this study, ultrasonic surface rolling processing (USRP) was employed to modify 7075 aluminum alloys with varying initial microstructure states (T6 and T4), successfully creating gradient structures (GSs) that exhibit both high strength and high plasticity, overcoming the traditional strength-plasticity trade-off in aluminum alloys. The results indicate that a GSs with a depth of up to 532 μm was achieved in the T4 state alloy (T4-USRP-A) through USRP followed by low-temperature aging. A nanocrystalline layer approximately 100 nm thick formed on the surface, significantly enhancing the yield strength (<em>R</em>_{<em>p</em>0.2}) and ultimate tensile strength (<em>R</em>_<em>m</em>) to 602.6 MPa and 691 MPa, respectively, while maintaining an elongation of 15%. The research further elucidated the microscopic characteristics of this GSs, which transitions continuously from nanocrystalline regions to deformable regions and dislocation-rich regions from the surface inward. Analysis based on the K-M model revealed that the alloy's high strength and plasticity are due to excellent dislocation storage and slow extinction properties, allowing the material to sustain a high strain hardening rate over a broad stress range, thus delaying necking. Additionally, this study developed a GSs synergistic strengthening model, quantifying the coordinated contribution of each gradient layer to the overall strength. This provides a crucial theoretical foundation and practical guidance for designing and preparing high-performance GSs aluminum alloys.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"523 ","pages":"Article 133221"},"PeriodicalIF":6.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of substrate roughness on AlCoCrFeNiNb0.6 HEA coating growth, adhesion and wear behavior","authors":"Filipe Caldatto Dalan ,&nbsp;Argemiro Soares da Silva Sobrinho ,&nbsp;Luis Marcelo Garcia da Silva ,&nbsp;Sydney Ferreira Santos ,&nbsp;André Ricardo Marcondes ,&nbsp;Kátia Regina Cardoso","doi":"10.1016/j.surfcoat.2026.133248","DOIUrl":"10.1016/j.surfcoat.2026.133248","url":null,"abstract":"<div><div>The influence of substrate surface roughness on the growth, adhesion, and tribological behavior of AlCoCrFeNiNb0.6 high-entropy alloy (HEA) coatings is reported in this manuscript. The coatings were deposited by magnetron sputtering onto API 5L X70 steel substrates using deposition powers of 100 W and 200 W. Two surface preparation conditions, mechanical polishing and abrasive blasting, were evaluated. Structural analysis by X-ray diffraction (XRD) indicated that the coatings were predominantly amorphous, while scanning electron microscopy (SEM) revealed that variations in morphology and thickness uniformity were dependent on both substrate topography and deposition power. Nanoindentation results showed hardness values of 9.9 GPa and 12.6 GPa, with corresponding elastic modulus of 189 GPa and 207 GPa, for coatings deposited at 100 W and 200 W, respectively. Adhesion tests demonstrated that increased substrate roughness significantly enhanced coating adhesion, with the critical load increasing from 316 mN to 4252 mN for the best-performing coating condition. For blasted substrates, the coefficient of friction was reduced from approximately 0.25 for the uncoated steel to values below 0.15 for the HEA-coated samples, with improved wear stability even under higher normal loads. Abrasive and fatigue wear mechanisms were predominant in the coated samples, whereas adhesive wear dominated the uncoated substrates. These results highlight that substrate surface condition is a key parameter for optimizing the adhesion and tribological performance of HEA coatings in mechanically demanding applications.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"523 ","pages":"Article 133248"},"PeriodicalIF":6.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146190510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Ni addition in AlSi hot-dip bath on microstructure, corrosion resistance, and hydrogen embrittlement of hot-press-formed steels","authors":"Dong-Gyu Kim ,&nbsp;N Rahul ,&nbsp;Sudipta Mohapatra ,&nbsp;Min-Suk Oh","doi":"10.1016/j.surfcoat.2026.133225","DOIUrl":"10.1016/j.surfcoat.2026.133225","url":null,"abstract":"<div><div>Hot-press forming (HPF) excels at manufacturing ultra-high-strength steel through a combination of elevated-temperature forming and in-die quenching. A critical component of this process is the application of Al<img>Si alloy coatings, which are essential for preserving the mechanical properties of steel by preventing decarburization during high-temperature processing. Adding Ni to these coatings shows strong promise for better properties, driven by the development of Ni-based intermetallics like Al₃Ni and Al₉FeNi. Ni additions at 0, 1, 3, and 5 wt% were introduced to the molten Al<img>Si bath to investigate changes in coating microstructure, hydrogen embrittlement (HE) susceptibility, and corrosion behavior post-HPF. With Ni present, intermetallics like Al₉FeNi and Al₃Ni developed on the coating surface as well as within the layer structure. During the HPF process, these intermetallics transformed into Al₅FeNi and localized on the surface of the coating. Ni incorporation substantially limited crack development through the coating thickness while blocking substrate contact with the electrolyte, thus boosting coated steel corrosion resistance. Moreover, Ni addition was found to decrease the formation of surface voids caused by hydrogen atoms; these voids typically occur because of the high reactivity of Al with moisture. Notably, the diffusible hydrogen content in samples containing 5 wt% Ni was reduced from 1.74 to 0.76 wppm immediately after the HPF process, indicating a substantial decrease in HE.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"523 ","pages":"Article 133225"},"PeriodicalIF":6.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146190512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of MoS2 lubricating coatings on the corrosion behaviour of monel 400 alloy","authors":"Qingkai Chu ,&nbsp;Huimin Liu ,&nbsp;Chujunwen Lu ,&nbsp;Qinghao Sun ,&nbsp;Julin Wang","doi":"10.1016/j.surfcoat.2026.133243","DOIUrl":"10.1016/j.surfcoat.2026.133243","url":null,"abstract":"<div><div>In this study, the corrosion behaviour of Monel 400 with and without a MoS₂ lubricating coating was comparatively analysed through electrochemical and salt spray corrosion experiments, alongside multiple characterization techniques. The coated samples exhibited significantly accelerated corrosion, with a 2.3-fold increase in corrosion rate during salt spray testing and a rise in corrosion current density from 0.49 μA·cm⁻² to 1.15 μA·cm⁻². Electrochemical impedance spectroscopy showed an 81.9% reduction in charge transfer resistance. The deterioration mechanism involves several interconnected processes: the MoS₂ coating promotes anodic dissolution while suppressing the formation of the protective passivation film (Cu₂O/Ni(OH)₂). XPS analysis revealed a corresponding increase in non-protective corrosion products, with the CuO/Cu₂O ratio rising from 0.47 to 0.86 and the NiCl₂/Ni(OH)₂ ratio from 0.40 to 0.68. The porous structure of the coating facilitated the adsorption and transport of corrosive media (Cl⁻, H₂O, O₂), leading to an increase in non-protective corrosion products (CuO/NiCl₂). Furthermore, the oxidation of MoS₂ to MoO₃ further disrupted the surface film and catalysed corrosion reactions. These mechanisms act synergistically, leading to a significant reduction in the corrosion resistance of Monel 400.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"523 ","pages":"Article 133243"},"PeriodicalIF":6.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of superhydrophobic anti-icing coatings guided by full-process machine learning","authors":"Zijie Zhang ,&nbsp;Yiming Liu ,&nbsp;Siyu Chen ,&nbsp;Lulu Liu ,&nbsp;Junjie Liu ,&nbsp;Tao Hu ,&nbsp;Ting Xiao ,&nbsp;Lihua Jiang ,&nbsp;Xu Li ,&nbsp;Xinyi Li ,&nbsp;Xinyu Tan","doi":"10.1016/j.surfcoat.2026.133235","DOIUrl":"10.1016/j.surfcoat.2026.133235","url":null,"abstract":"<div><div>Superhydrophobic coatings hold immense potential in anti-icing applications. The preparation of superhydrophobic anti-icing coatings involves multi-parameter design such as coating components and substrate structures, which leads to high trial-and-error rates and unclear directionality in performance optimization. Here, we first report a full-process machine learning framework that integrates large language model, post-hoc explainable machine learning model, and Bayesian Optimization framework to guide the preparation of superhydrophobic coating with superior anti-icing performance. The FPMLF autonomously collected 217 sets of coating components data from 2315 published articles, constructed a regression model for coating components design based on the collected data, and achieved the high throughput screening and optimization of the complex process parameters of the substrate structure. Guided by this framework, we successfully fabricated a coating exhibiting a freezing delay time over 30-fold longer than bare substrate. This work provides systematic support and a methodological foundation for the rational design of advanced functional materials with coupled and complex performance requirements.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"523 ","pages":"Article 133235"},"PeriodicalIF":6.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146090277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of B4C-induced in-situ ceramic reinforcing phases on the mechanical properties of FeCoCrNiMnTi₀.₅Al₀.₅ high-entropy alloy coatings","authors":"Fengyuan Guo ,&nbsp;Chuanwei Shi ,&nbsp;Lingchen Kong ,&nbsp;Shenhao Wang ,&nbsp;Zhiheng Zhu ,&nbsp;Junjie Zhao ,&nbsp;Mengjie Liao","doi":"10.1016/j.surfcoat.2026.133189","DOIUrl":"10.1016/j.surfcoat.2026.133189","url":null,"abstract":"<div><div>In this study, FeCoCrNiMnTi₀.₅Al₀.₅/B₄C coatings with different B₄C contents (0, 1, 3, 5, 7, and 9 wt%) were fabricated on AISI 1045 steel by laser cladding to investigate the effect of B₄C on the evolution of microstructure and wear resistance. With increasing B₄C content, in-situ reactions during solidification produced TiC, Ti(C,B), and CrB ceramic phases, transforming the coating from a dual-phase (BCC/FCC) to a multiphase structure. The microstructure evolved from columnar to equiaxed and eventually to acicular grains. For the S4 coating, EBSD analyses revealed reduced texture strength and moderate dislocation density, contributing to enhanced strength. Grain refinement and dispersion of in-situ ceramics jointly improved the microhardness and wear resistance. The S4 coating exhibited optimal performance, with a wear rate of only 2.2% that of the AISI 1045 steel substrate. However, excessive B₄C caused CrB coarsening and brittle fracture, leading to accelerated three-body abrasive wear. At 600 °C, the uniformly distributed TiC, Ti(C,B), and CrB-rich phases exhibited excellent thermal stability, enhancing hardness and resistance to plastic deformation. Furthermore, these ceramic phases promoted the formation of a dense and continuous oxide film with self-lubricating and self-healing characteristics, markedly reducing the friction coefficient and wear rate. This study elucidates the dual strengthening and protection mechanisms provided by the in-situ ceramic phases and demonstrates that an optimized B₄C content enables superior tribological performance of the coatings under both room-temperature and 600 °C wear conditions.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"523 ","pages":"Article 133189"},"PeriodicalIF":6.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146039740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrochemically enhanced uniform TiO₂ films on TA1 titanium via stepwise anodizing: Decoupling grain-orientation effects and corrosion-resistance mechanisms","authors":"Qiang Zhong ,&nbsp;Changrong Ran ,&nbsp;zhengjie Chen ,&nbsp;Xueqiang Dong ,&nbsp;Zeyao Zeng ,&nbsp;Xu Luo ,&nbsp;Wei Li ,&nbsp;Jin Na ,&nbsp;Lu Wang ,&nbsp;Jinwen Ye","doi":"10.1016/j.surfcoat.2025.133120","DOIUrl":"10.1016/j.surfcoat.2025.133120","url":null,"abstract":"<div><div>This study elucidated the critical roles of grain orientation and microstructural homogeneity in governing the growth, uniformity, and electrochemical corrosion resistance of anodizing TiO₂ films on TA1 titanium. Recrystallized TA1, with a nearly uniform grain structure (median grain-size deviation ≈0.61 μm), exhibited low color difference (<span><math><mi>ΔE</mi></math></span> ≈ 0.46–0.56) and stable interference colors over 50–110 V, whereas phase-transformed TA1, with a ∼ 20-fold larger median deviation (≈65.71 μm), contained coarse, anisotropic grains that caused pronounced color non-uniformity. Further investigations confirmed that a 2093 mV surface potential difference between <span><math><mfenced><mrow><mn>11</mn><mover><mn>2</mn><mo>¯</mo></mover><mn>0</mn></mrow></mfenced><mfenced><mn>0001</mn></mfenced></math></span> and <span><math><mfenced><mn>0001</mn></mfenced><mfenced><mrow><mn>11</mn><mover><mn>2</mn><mo>¯</mo></mover><mn>0</mn></mrow></mfenced></math></span>grains tilted 45° along the TD direction dictated localized discharge dynamics, directly resulting in a 46.7 nm thickness disparity (107.6 nm purple vs. 154.3 nm yellow layers) under 70 V anodizing. This orientation-dependent thickness contrast mechanistically explained the macroscopic color demarcation through interference principles. To eliminate these variations, a stepwise anodizing strategy was developed, in which secondary anodizing was used to redistribute the electric potential and promote preferential growth in thinner-film regions, thereby markedly enhancing TiO₂ film uniformity. Electrochemical tests in seawater showed that such uniform films exhibited higher low-frequency impedance and a higher barrier-layer resistance R_m (457–3248 Ω·cm²), thereby affording superior corrosion resistance. These findings not only clarified the mechanism of anisotropic anodizing behavior but also provided a practical approach to fabricate uniform, highly protective, and functional titanium surfaces for marine and biomedical applications.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"523 ","pages":"Article 133120"},"PeriodicalIF":6.1,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145996319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}