Pub Date : 2025-12-31DOI: 10.1016/j.surfcoat.2025.133145
Chunyan He , Shuangjian Li , Zhongwu Liu , Jie Zhou , Qian Lin , Xiujuan Fan , Jinming Liu , Tingting Guo , Guifeng Tao , Jing Yang
Traditional thermal-sprayed Al2O3-3wt.%TiO2 (AT3) coatings and ion-deposited diamond-like carbon (DLC) films are currently research hotspots in the field of surface engineering. However, the differences between these two materials make their combination and synergistic interaction a key challenge in this field. To overcome this, we designed a dual-gradient transitional interlayer (in composition and structure) between an AT3 coating and a DLC film using a combined thermal spraying and ion deposition process. This approach enables the fabrication of a composite coating with superior comprehensive properties. The design of a structural gradient interlayer alleviated the internal stress between the bottom and top layers, thereby enhancing the mechanical properties of the coating. This results in a friction coefficient of 0.12 and a specific wear rate that decreases from 3.14 × 10−5 mm3·N−1·m−1 to 2.72 × 10−6 mm3·N−1·m−1. The corrosion resistance of the coating was significantly improved, the AT3/MTL/DLC coating exhibits a polarization resistance (Rp) of 4.178 × 106 Ω·cm2, surpassing the pure AT3 coating by two orders of magnitude. This study presents a novel protection strategy for wear-resistant and anti-corrosive moving components in marine environments, and it is anticipated to possess substantial application potential in extensive engineering fields.
{"title":"A dual-gradient transition layer design achieving “three things at one stroke” for thermal-sprayed ceramic/diamond-like carbon coatings: Microstructure, corrosion resistance, and tribological performance","authors":"Chunyan He , Shuangjian Li , Zhongwu Liu , Jie Zhou , Qian Lin , Xiujuan Fan , Jinming Liu , Tingting Guo , Guifeng Tao , Jing Yang","doi":"10.1016/j.surfcoat.2025.133145","DOIUrl":"10.1016/j.surfcoat.2025.133145","url":null,"abstract":"<div><div>Traditional thermal-sprayed Al<sub>2</sub>O<sub>3</sub>-3wt.%TiO<sub>2</sub> (AT3) coatings and ion-deposited diamond-like carbon (DLC) films are currently research hotspots in the field of surface engineering. However, the differences between these two materials make their combination and synergistic interaction a key challenge in this field. To overcome this, we designed a dual-gradient transitional interlayer (in composition and structure) between an AT3 coating and a DLC film using a combined thermal spraying and ion deposition process. This approach enables the fabrication of a composite coating with superior comprehensive properties. The design of a structural gradient interlayer alleviated the internal stress between the bottom and top layers, thereby enhancing the mechanical properties of the coating. This results in a friction coefficient of 0.12 and a specific wear rate that decreases from 3.14 × 10<sup>−5</sup> mm<sup>3</sup>·N<sup>−1</sup>·m<sup>−1</sup> to 2.72 × 10<sup>−6</sup> mm<sup>3</sup>·N<sup>−1</sup>·m<sup>−1</sup>. The corrosion resistance of the coating was significantly improved, the AT3/MTL/DLC coating exhibits a polarization resistance (R<sub>p</sub>) of 4.178 × 10<sup>6</sup> Ω·cm<sup>2</sup>, surpassing the pure AT3 coating by two orders of magnitude. This study presents a novel protection strategy for wear-resistant and anti-corrosive moving components in marine environments, and it is anticipated to possess substantial application potential in extensive engineering fields.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"521 ","pages":"Article 133145"},"PeriodicalIF":6.1,"publicationDate":"2025-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145926945","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}
Pub Date : 2025-12-31DOI: 10.1016/j.surfcoat.2025.133141
Haiyan Liao , Haibo Ruan , Weijiu Huang , Jin Hu , Yuan Niu , Hao Peng , Xiangkong Xu , Xiaohan Deng , Tao Hao , Yongyao Su
To suppress ZrCr interdiffusion and improve the oxidation resistance of Cr-coated Zircaloy-4 in high-temperature steam, CrN (15.5 at.% N) and metallic Cr coatings were prepared by magnetron sputtering. Their oxidation behavior and microstructure evolution at 1200 °C and 1300 °C were investigated. The nanocrystalline CrN coating rapidly forms a dense Cr2O3 layer that retains N, thereby promoting the formation of Cr2N and alleviating stress to maintain Cr2O3 scale integrity. Temperature strongly affects the oxidized microstructure. At 1200 °C, the layered structure comprises Cr2O3/Cr2N/Cr/Zr-N(α-Zr(N) + ZrN), whereas it evolves to Cr2O3/Cr/ZrCr2/α-Zr(N) at 1300 °C. The in-situ formed ZrN layer during high-temperature oxidation acts as a critical diffusion barrier. Notably, in the Cr-N-coated sample, the ZrCr2 layer is only 265 nm thick at 1300 °C, compared with 2.0 μm in the metallic Cr-coated sample. These results indicate that the α-Zr(N) phase effectively retards interdiffusion and highlight the potential of CrN coatings for high-temperature steam environments.
{"title":"Enhanced oxidation resistance of CrN coated Zircaloy-4 in steam via a ZrN diffusion barrier formed during high-temperature exposure","authors":"Haiyan Liao , Haibo Ruan , Weijiu Huang , Jin Hu , Yuan Niu , Hao Peng , Xiangkong Xu , Xiaohan Deng , Tao Hao , Yongyao Su","doi":"10.1016/j.surfcoat.2025.133141","DOIUrl":"10.1016/j.surfcoat.2025.133141","url":null,"abstract":"<div><div>To suppress Zr<img>Cr interdiffusion and improve the oxidation resistance of Cr-coated Zircaloy-4 in high-temperature steam, Cr<img>N (15.5 at.% N) and metallic Cr coatings were prepared by magnetron sputtering. Their oxidation behavior and microstructure evolution at 1200 °C and 1300 °C were investigated. The nanocrystalline Cr<img>N coating rapidly forms a dense Cr<sub>2</sub>O<sub>3</sub> layer that retains N, thereby promoting the formation of Cr<sub>2</sub>N and alleviating stress to maintain Cr<sub>2</sub>O<sub>3</sub> scale integrity. Temperature strongly affects the oxidized microstructure. At 1200 °C, the layered structure comprises Cr<sub>2</sub>O<sub>3</sub>/Cr<sub>2</sub>N/Cr/Zr-N(α-Zr(N) + ZrN), whereas it evolves to Cr<sub>2</sub>O<sub>3</sub>/Cr/ZrCr<sub>2</sub>/α-Zr(N) at 1300 °C. The in-situ formed Zr<img>N layer during high-temperature oxidation acts as a critical diffusion barrier. Notably, in the Cr-N-coated sample, the ZrCr<sub>2</sub> layer is only 265 nm thick at 1300 °C, compared with 2.0 μm in the metallic Cr-coated sample. These results indicate that the α-Zr(N) phase effectively retards interdiffusion and highlight the potential of Cr<img>N coatings for high-temperature steam environments.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"521 ","pages":"Article 133141"},"PeriodicalIF":6.1,"publicationDate":"2025-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145926944","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}
Pub Date : 2025-12-30DOI: 10.1016/j.surfcoat.2025.133125
Xiao Tao , Yunus Azakli , Linshan Yu , Adrian Leyland , Hanshan Dong , Allan Matthews , Haitao Zhao , Junheng Gao , Jian Chen
The carbide-free, carbon-supersaturated expanded austenite (γC) case in low-temperature carburized (LTC) AISI 316 (Fe-18Cr-11Ni-3Mo, wt%) austenitic stainless steel (SS) drawn extensive interests for its high hardness and good corrosion resistance. The addition of strong carbide-forming elements (e.g. Ti) in the substrate alloy would significantly improve the hardening of γC, but also tends to accelerate carbide formation that would deteriorate corrosion resistance. Nevertheless, increasing the Ni level would improve the stability of the austenitic structure and tends to prohibit carbide formation in the carburized surface, that could compensate with the Ti addition in matrix. The impacts of increasing Ni/Ti concentrations (either separately or combined) in Fe-Cr-Ni-Me (Me = strong carbide forming elements) austenitic matrix to the surface carburizing response and performance requires systematic examination. Following the above alloy-design concept, Fe-18Cr-18/35Ni(-2Ti) alloys containing approximately 18 wt% Cr and 18/35 wt% Ni, without and with ∼2 wt% Ti, are tentatively investigated after plasma carburizing at 470 and 520 °C for 15 h, respectively. The surface carbon uptake during carburizing and the resulting surface hardness reduce with increasing substrate Ni level, increase substantially with Ti addition in the substrate alloy. Both substrate Ni/Ti additions improve the corrosion resistance of the plasma carburized surfaces. Strikingly, when carburized at 470 °C/15 h, the γC case is significantly thicker and harder in Fe-18Cr-18Ni-2Ti (35 μm, 1009 HV0.3) than that in AISI 316 SS (25 μm, 450 HV0.3). Moreover, the carburized surfaces of high-Ni/Ti alloys exhibit sluggish carbide formation and improved corrosion resistance than those of AISI 316 SS. This study i) reveals the alloy-design criteria to enhancing hardening, while improving corrosion resistance, for γC, and ii) guides the development of carburizing process for specialty corrosion-resistant austenitic alloys.
{"title":"Influences of Ni and Ti concentrations on the carbon uptake, carbide formation, hardening and corrosion performance of the carbon-expanded austenite case in austenitic Fe-Cr-Ni-Ti alloys","authors":"Xiao Tao , Yunus Azakli , Linshan Yu , Adrian Leyland , Hanshan Dong , Allan Matthews , Haitao Zhao , Junheng Gao , Jian Chen","doi":"10.1016/j.surfcoat.2025.133125","DOIUrl":"10.1016/j.surfcoat.2025.133125","url":null,"abstract":"<div><div>The carbide-free, carbon-supersaturated expanded austenite (γ<sub>C</sub>) case in low-temperature carburized (LTC) AISI 316 (Fe-18Cr-11Ni-3Mo, wt%) austenitic stainless steel (SS) drawn extensive interests for its high hardness and good corrosion resistance. The addition of strong carbide-forming elements (e.g. Ti) in the substrate alloy would significantly improve the hardening of γ<sub>C</sub>, but also tends to accelerate carbide formation that would deteriorate corrosion resistance. Nevertheless, increasing the Ni level would improve the stability of the austenitic structure and tends to prohibit carbide formation in the carburized surface, that could compensate with the Ti addition in matrix. The impacts of increasing Ni/Ti concentrations (either separately or combined) in Fe-Cr-Ni-Me (Me = strong carbide forming elements) austenitic matrix to the surface carburizing response and performance requires systematic examination. Following the above alloy-design concept, Fe-18Cr-18/35Ni(-2Ti) alloys containing approximately 18 wt% Cr and 18/35 wt% Ni, without and with ∼2 wt% Ti, are tentatively investigated after plasma carburizing at 470 and 520 °C for 15 h, respectively. The surface carbon uptake during carburizing and the resulting surface hardness reduce with increasing substrate Ni level, increase substantially with Ti addition in the substrate alloy. Both substrate Ni/Ti additions improve the corrosion resistance of the plasma carburized surfaces. Strikingly, when carburized at 470 °C/15 h, the γ<sub>C</sub> case is significantly thicker and harder in Fe-18Cr-18Ni-2Ti (35 μm, 1009 HV<sub>0.3</sub>) than that in AISI 316 SS (25 μm, 450 HV<sub>0.3</sub>). Moreover, the carburized surfaces of high-Ni/Ti alloys exhibit sluggish carbide formation and improved corrosion resistance than those of AISI 316 SS. This study i) reveals the alloy-design criteria to enhancing hardening, while improving corrosion resistance, for γ<sub>C</sub>, and ii) guides the development of carburizing process for specialty corrosion-resistant austenitic alloys.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"522 ","pages":"Article 133125"},"PeriodicalIF":6.1,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928880","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}
Monel 400 cladding exhibits substantial potential as a premier material in marine applications owing to its superior mechanical strength and outstanding corrosion resistance. However, the detailed analysis of Monel 400 clad on the stainless steel (SS) 304 substrate in terms of grain microstructure, mechanical properties, and the corresponding mechanism remains unclear. Herein, a cold metal transfer (CMT) based wire arc additive manufacturing process (WAAM) was utilized to deposit a single layer of Monel 400 on SS 304. Microstructural analysis revealed the fragmented and elongated dendrites on the clad surface. In contrast, equiaxed austenite (γ) grains, bounded with a small delta ferrite (δ), were present on the SS 304 base substrate. EDS (Energy Dispersive Spectroscopy) analysis identified two types of intermetallic phases at the interface, namely FeNi and NiCr. XRD (X-ray Diffraction) results confirmed the presence of an FCC structure, along with the formation of new intermetallic phases at the interface. EBSD (Electron Backscatter Diffraction) analysis indicated that Continuous Dynamic Recrystallization (CDRX) and Geometric Dynamic Recrystallization (GDRX) predominated at the clad surface, while Discontinuous Dynamic Recrystallization (DDRX) was the primary mechanism within the SS 304 substrate. The quantitative analysis revealed grain sizes of 86 ± 5 μm and 9 ± 2 μm for the clad surface and base substrate, respectively. Mechanical analysis showed that the clad surface exhibits 25 % higher tensile strength than the interface and 55 % higher tensile strength than the base substrate. Moreover, delamination analysis confirmed the strong metallurgical bonding between the Monel 400 and SS 304. This study demonstrates the feasibility of cold metal transfer–based wire arc additive manufacturing (CMT-WAAM) for Monel 400 cladding on SS 304 with promising interfacial integrity and mechanical performance.
{"title":"Microstructure and mechanical performance of Monel 400 cladding on SS-304 using CMT-WAAM","authors":"Lalit Kumar Yadav , Joy Prakash Misra , Rajnesh Tyagi , Shubham Verma","doi":"10.1016/j.surfcoat.2025.133140","DOIUrl":"10.1016/j.surfcoat.2025.133140","url":null,"abstract":"<div><div>Monel 400 cladding exhibits substantial potential as a premier material in marine applications owing to its superior mechanical strength and outstanding corrosion resistance. However, the detailed analysis of Monel 400 clad on the stainless steel (SS) 304 substrate in terms of grain microstructure, mechanical properties, and the corresponding mechanism remains unclear. Herein, a cold metal transfer (CMT) based wire arc additive manufacturing process (WAAM) was utilized to deposit a single layer of Monel 400 on SS 304. Microstructural analysis revealed the fragmented and elongated dendrites on the clad surface. In contrast, equiaxed austenite (γ) grains, bounded with a small delta ferrite (δ), were present on the SS 304 base substrate. EDS (Energy Dispersive Spectroscopy) analysis identified two types of intermetallic phases at the interface, namely Fe<img>Ni and Ni<img>Cr. XRD (X-ray Diffraction) results confirmed the presence of an FCC structure, along with the formation of new intermetallic phases at the interface. EBSD (Electron Backscatter Diffraction) analysis indicated that Continuous Dynamic Recrystallization (CDRX) and Geometric Dynamic Recrystallization (GDRX) predominated at the clad surface, while Discontinuous Dynamic Recrystallization (DDRX) was the primary mechanism within the SS 304 substrate. The quantitative analysis revealed grain sizes of 86 ± 5 μm and 9 ± 2 μm for the clad surface and base substrate, respectively. Mechanical analysis showed that the clad surface exhibits 25 % higher tensile strength than the interface and 55 % higher tensile strength than the base substrate. Moreover, delamination analysis confirmed the strong metallurgical bonding between the Monel 400 and SS 304. This study demonstrates the feasibility of cold metal transfer–based wire arc additive manufacturing (CMT-WAAM) for Monel 400 cladding on SS 304 with promising interfacial integrity and mechanical performance.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"522 ","pages":"Article 133140"},"PeriodicalIF":6.1,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145898176","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}
Pub Date : 2025-12-29DOI: 10.1016/j.surfcoat.2025.133136
Shihao You , Xingwu Qiu , Ziyi Wang , Xianwen Shen , Yan Zhou , Boyang Shen , Zhongyi Liu , Yu Zhang , Hang Chen , Chao Meng
In this study, AlxNbTiVSi0.1 (x = 0.5, 0.75, 1, 1.25, 1.5) lightweight refractory high-entropy alloy (LRHEA) coatings were successfully fabricated on the surface of TC4 titanium alloy substrates by gas tungsten arc (GTA) cladding. The results indicated that AlxNbTiVSi0.1 LRHEA coatings were composed of BCC, TiNb, and (Nb, Ti)5Si3 phases. With increasing Al content, the fraction of the BCC phase increased, whereas both the size and fraction of TiNb phase decreased. The average hardness at the top of coatings increased with Al content, reaching a maximum of 842.55 HV0.5 for Al1.5NbTiVSi0.1 LRHEA coating. Wear tests demonstrated that the Al1NbTiVSi0.1 LRHEA coating exhibited optimal wear resistance at both room temperature and 600 °C, with mass loss rates of 2.01 × 10−5 mg/mm and 0.42 × 10−5 mg/mm, respectively. Furthermore, electrochemical tests further revealed that an increased Al content significantly improved the corrosion resistance. The Al1.5NbTiVSi0.1 LRHEA coating exhibited the highest corrosion potential (−207.56 mV) and the lowest corrosion current density (2.37 × 10−7 A/cm2). Moreover, with increasing Al content, the corrosion mechanism transformed from severe galvanic corrosion to slight pitting due to the formation of a protective passive film. This study provides valuable insights for the compositional design and performance optimization of LRHEA coatings.
{"title":"Effect of Al content on the microstructure, wear and corrosion resistance of AlxNbTiVSi0.1 lightweight refractory high-entropy alloy coatings by gas tungsten Arc cladding","authors":"Shihao You , Xingwu Qiu , Ziyi Wang , Xianwen Shen , Yan Zhou , Boyang Shen , Zhongyi Liu , Yu Zhang , Hang Chen , Chao Meng","doi":"10.1016/j.surfcoat.2025.133136","DOIUrl":"10.1016/j.surfcoat.2025.133136","url":null,"abstract":"<div><div>In this study, Al<sub>x</sub>NbTiVSi<sub>0.1</sub> (x = 0.5, 0.75, 1, 1.25, 1.5) lightweight refractory high-entropy alloy (LRHEA) coatings were successfully fabricated on the surface of TC4 titanium alloy substrates by gas tungsten arc (GTA) cladding. The results indicated that Al<sub>x</sub>NbTiVSi<sub>0.1</sub> LRHEA coatings were composed of BCC, Ti<img>Nb, and (Nb, Ti)<sub>5</sub>Si<sub>3</sub> phases. With increasing Al content, the fraction of the BCC phase increased, whereas both the size and fraction of Ti<img>Nb phase decreased. The average hardness at the top of coatings increased with Al content, reaching a maximum of 842.55 HV<sub>0.5</sub> for Al<sub>1.5</sub>NbTiVSi<sub>0.1</sub> LRHEA coating. Wear tests demonstrated that the Al<sub>1</sub>NbTiVSi<sub>0.1</sub> LRHEA coating exhibited optimal wear resistance at both room temperature and 600 °C, with mass loss rates of 2.01 × 10<sup>−5</sup> mg/mm and 0.42 × 10<sup>−5</sup> mg/mm, respectively. Furthermore, electrochemical tests further revealed that an increased Al content significantly improved the corrosion resistance. The Al<sub>1.5</sub>NbTiVSi<sub>0.1</sub> LRHEA coating exhibited the highest corrosion potential (−207.56 mV) and the lowest corrosion current density (2.37 × 10<sup>−7</sup> A/cm<sup>2</sup>). Moreover, with increasing Al content, the corrosion mechanism transformed from severe galvanic corrosion to slight pitting due to the formation of a protective passive film. This study provides valuable insights for the compositional design and performance optimization of LRHEA coatings.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"521 ","pages":"Article 133136"},"PeriodicalIF":6.1,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885339","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}
Pub Date : 2025-12-29DOI: 10.1016/j.surfcoat.2025.133129
Christine Regent , Marie-Laure Doche , Loïc Hallez , Bruno Vuillemin , Vincent Vignal , Aurélien Boucher , Sudipta Roy
Although there has been a growing interest in nanoscale texturing of steel, there have been few papers focused on the processes accompanying the phenomenon. The current work examines if the formation of a viscous layer is a necessary condition for surface texturing of steel, and probes the underlying processes leading to pattern formation in an electrolyte originally developed for electropolishing. The investigation involved nanotexturing SS grade 316 L anodization using an ethylene glycol-perchloric acid electrolyte and constant current between 1 and 10 A·dm−2. During the experiment, the viscous layer formation or surface modification as well as the potential response are simultaneously monitored. Two different electrode orientations, horizontal and vertical, are examined. The horizontal orientation stops convection at the vicinity of the electrode whereas the vertically oriented electrode would have convective flows at the electrode vicinity. The effect of surface preparation, through different mechanical polishing conditions, on the pore formation has also been examined. The results clearly showed the formation of viscous layer at the surface preceding surface texturing. The pore size was controlled by the applied current and reached 370 nm, with optimal current density being 5 A·dm−2. Visualization of the electrode surface showed that one achieved a stable viscous film at a horizontal electrode. For the vertically oriented electrodes gravitational flows of the viscous layer were observed. The resistive contribution of the viscous layer was assessed around 0.50–0.70 Ω·dm2. Analysis of potential changes also showed a voltage surge occurred during the formation of a compact layer. It was found that just at the point of completion of viscous layer, texturing commences, indicating that formation of a viscous layer or salt film is essential to the texturing process. Further analysis using the Sand equation showed electropolishing occurred due to diffusion-controlled transport through the viscous film.
{"title":"Viscous layer formation during electropolishing and nano-texturing of 316 L stainless steel in ethylene glycol-perchloric acid using current controlled anodizing","authors":"Christine Regent , Marie-Laure Doche , Loïc Hallez , Bruno Vuillemin , Vincent Vignal , Aurélien Boucher , Sudipta Roy","doi":"10.1016/j.surfcoat.2025.133129","DOIUrl":"10.1016/j.surfcoat.2025.133129","url":null,"abstract":"<div><div>Although there has been a growing interest in nanoscale texturing of steel, there have been few papers focused on the processes accompanying the phenomenon. The current work examines if the formation of a viscous layer is a necessary condition for surface texturing of steel, and probes the underlying processes leading to pattern formation in an electrolyte originally developed for electropolishing. The investigation involved nanotexturing SS grade 316 L anodization using an ethylene glycol-perchloric acid electrolyte and constant current between 1 and 10 A·dm<sup>−2</sup>. During the experiment, the viscous layer formation or surface modification as well as the potential response are simultaneously monitored. Two different electrode orientations, horizontal and vertical, are examined. The horizontal orientation stops convection at the vicinity of the electrode whereas the vertically oriented electrode would have convective flows at the electrode vicinity. The effect of surface preparation, through different mechanical polishing conditions, on the pore formation has also been examined. The results clearly showed the formation of viscous layer at the surface preceding surface texturing. The pore size was controlled by the applied current and reached 370 nm, with optimal current density being 5 A·dm<sup>−2</sup>. Visualization of the electrode surface showed that one achieved a stable viscous film at a horizontal electrode. For the vertically oriented electrodes gravitational flows of the viscous layer were observed. The resistive contribution of the viscous layer was assessed around 0.50–0.70 Ω·dm<sup>2</sup>. Analysis of potential changes also showed a voltage surge occurred during the formation of a compact layer. It was found that just at the point of completion of viscous layer, texturing commences, indicating that formation of a viscous layer or salt film is essential to the texturing process. Further analysis using the Sand equation showed electropolishing occurred due to diffusion-controlled transport through the viscous film.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"522 ","pages":"Article 133129"},"PeriodicalIF":6.1,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928886","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}
Pub Date : 2025-12-29DOI: 10.1016/j.surfcoat.2025.133133
Pengxing Yu , Ruoyun Wang , Kai Wang , Huabing Liu , Biyou Peng , Hongjian Huang , Junwu Xiang , Haiyang Zhou , Tong Zhou
To enhance the long-term corrosion resistance of 3D-printed AlSi10Mg alloy, this work designed a two-step micro-arc oxidation (MAO) strategy. Given the difficulty of triggering micro-arc discharge in high-Si Al alloys, an intermediate transition layer was first prepared through one-step MAO in a silicate electrolyte. Subsequently, a two-step MAO treatment was performed in a phosphate electrolyte with the addition of K2ZrF6 to seal the ablation holes formed during the one-step MAO process, achieving a self-sealing effect of the MAO coating. Ultimately, a dense ZrO2/Al2O3 ceramic coating with Si-W-Zr-P gradient distribution was obtained on the AlSi10Mg surface after the two-step MAO. Electrochemical tests reveal that the two-step MAO coating exhibits exceptional corrosion resistance, with a remarkably low corrosion current density (Icorr) of 3.42 × 10−9 A·cm−2, along with a protective efficiency (ηp) of up to 99.8 %. Moreover, no obvious macroscopic corrosion signs are observed on the ZrO2/Al2O3 coating after prolonged immersion, and its Icorr remains stable at 9.26 × 10−9 A·cm−2, indicating durable protective performance. This study offers a novel and controllable strategy for the design of anti-corrosive coatings on 3D-printed high-Si Al alloys.
{"title":"In-situ fabrication of durable corrosion-resistant ZrO2/Al2O3 coating on 3D-printed AlSi10Mg via two-step micro-arc oxidation","authors":"Pengxing Yu , Ruoyun Wang , Kai Wang , Huabing Liu , Biyou Peng , Hongjian Huang , Junwu Xiang , Haiyang Zhou , Tong Zhou","doi":"10.1016/j.surfcoat.2025.133133","DOIUrl":"10.1016/j.surfcoat.2025.133133","url":null,"abstract":"<div><div>To enhance the long-term corrosion resistance of 3D-printed AlSi10Mg alloy, this work designed a two-step micro-arc oxidation (MAO) strategy. Given the difficulty of triggering micro-arc discharge in high-Si Al alloys, an intermediate transition layer was first prepared through one-step MAO in a silicate electrolyte. Subsequently, a two-step MAO treatment was performed in a phosphate electrolyte with the addition of K<sub>2</sub>ZrF<sub>6</sub> to seal the ablation holes formed during the one-step MAO process, achieving a self-sealing effect of the MAO coating. Ultimately, a dense ZrO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> ceramic coating with Si-W-Zr-P gradient distribution was obtained on the AlSi10Mg surface after the two-step MAO. Electrochemical tests reveal that the two-step MAO coating exhibits exceptional corrosion resistance, with a remarkably low corrosion current density (I<sub>corr</sub>) of 3.42 × 10<sup>−9</sup> A·cm<sup>−2</sup>, along with a protective efficiency (η<sub>p</sub>) of up to 99.8 %. Moreover, no obvious macroscopic corrosion signs are observed on the ZrO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> coating after prolonged immersion, and its I<sub>corr</sub> remains stable at 9.26 × 10<sup>−9</sup> A·cm<sup>−2</sup>, indicating durable protective performance. This study offers a novel and controllable strategy for the design of anti-corrosive coatings on 3D-printed high-Si Al alloys.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"521 ","pages":"Article 133133"},"PeriodicalIF":6.1,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885342","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}
Pub Date : 2025-12-29DOI: 10.1016/j.surfcoat.2025.133131
Yuxi Zhang , Jiarong Lu , Guojun Zhang
This study develops a novel in-situ construction strategy for fabricating micro-nano hierarchical structures on copper substrates through electroless copper plating and chemical oxidation. This method represents a significant advancement beyond conventional fabrication approaches by eliminating the requirement for low surface energy chemical modifications. The resulting Cu/CuO dual-phase composite surface demonstrates stable superhydrophobicity with a high water contact angle (WCA) of 164.5 ± 1° and a low sliding angle (SA) of 4.9 ± 0.5°. The fabricated superhydrophobic coating exhibited one order of magnitude reduction in corrosion current density compared to bare copper, accompanied by a corrosion inhibition efficiency of 91.22 %, demonstrating exceptional corrosion resistance performance in 3.5 wt% NaCl aqueous solution. Furthermore, the fabricated superhydrophobic coating demonstrated exceptional wear resistance and self-cleaning properties, maintaining its superhydrophobicity over an abrasion distance of 1.8 m on 240 mesh SiC sandpaper under controlled testing conditions (1.9 kPa). Systematic characterization through SEM, XRD, and 3D profilometry elucidated the correlation between surface wettability and multiscale surface topography.
{"title":"Facile synthesis of Cu/CuO hierarchical micro-nano architectures for durable superhydrophobic coatings exhibiting enhanced corrosion resistance","authors":"Yuxi Zhang , Jiarong Lu , Guojun Zhang","doi":"10.1016/j.surfcoat.2025.133131","DOIUrl":"10.1016/j.surfcoat.2025.133131","url":null,"abstract":"<div><div>This study develops a novel in-situ construction strategy for fabricating micro-nano hierarchical structures on copper substrates through electroless copper plating and chemical oxidation. This method represents a significant advancement beyond conventional fabrication approaches by eliminating the requirement for low surface energy chemical modifications. The resulting Cu/CuO dual-phase composite surface demonstrates stable superhydrophobicity with a high water contact angle (WCA) of 164.5 ± 1° and a low sliding angle (SA) of 4.9 ± 0.5°. The fabricated superhydrophobic coating exhibited one order of magnitude reduction in corrosion current density compared to bare copper, accompanied by a corrosion inhibition efficiency of 91.22 %, demonstrating exceptional corrosion resistance performance in 3.5 wt% NaCl aqueous solution. Furthermore, the fabricated superhydrophobic coating demonstrated exceptional wear resistance and self-cleaning properties, maintaining its superhydrophobicity over an abrasion distance of 1.8 m on 240 mesh SiC sandpaper under controlled testing conditions (1.9 kPa). Systematic characterization through SEM, XRD, and 3D profilometry elucidated the correlation between surface wettability and multiscale surface topography.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"521 ","pages":"Article 133131"},"PeriodicalIF":6.1,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885359","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}
Pub Date : 2025-12-29DOI: 10.1016/j.surfcoat.2025.133132
Yaxia Liu , Hongxi Liu , Chen Yang , Ming Wen , Ben Niu , Xiaowei Zhang , Haifang Liu
An Al0.3TiZrNb high-entropy alloy coating (HEAC) was prepared by laser cladding and subsequently isothermally aged at 800 °C for 1, 2, and 4 h. The effects of ageing time on the microstructure, mechanical properties, and wear behavior of the Al0.3TiZrNb HEAC were investigated. The Al0.3TiZrNb HEAC has a single BCC solid solution structure. After the ageing treatment, the ZrAl nanoprecipitates gradually formed near the grain boundaries; when the ageing time was prolonged, compared with those of Al0.3TiZrNb HEAC, the number of nanoprecipitates increased, and the grain size was obviously refined. Notably, the coating that was aged for 2 h had the greatest number of precipitates and the smallest grain size, indicating the best deformation resistance and wear resistance. Specifically, the interaction between the precipitates and high-density dislocations produced a strain-hardening effect, which enhanced the fracture toughness of the coating, changed its wear mechanism, and improved its wear resistance. This study reveals the key role of precipitation strengthening in enhancing the mechanical and wear resistance of Al0.3TiZrNb HEAC, thus increasing its potential for industrial applications.
{"title":"Effect of aging time on precipitation behaviors, mechanical properties, and wear resistance of Al0.3TiZrNb high-entropy alloy coating","authors":"Yaxia Liu , Hongxi Liu , Chen Yang , Ming Wen , Ben Niu , Xiaowei Zhang , Haifang Liu","doi":"10.1016/j.surfcoat.2025.133132","DOIUrl":"10.1016/j.surfcoat.2025.133132","url":null,"abstract":"<div><div>An Al<sub>0.3</sub>TiZrNb high-entropy alloy coating (HEAC) was prepared by laser cladding and subsequently isothermally aged at 800 °C for 1, 2, and 4 h. The effects of ageing time on the microstructure, mechanical properties, and wear behavior of the Al<sub>0.3</sub>TiZrNb HEAC were investigated. The Al<sub>0.3</sub>TiZrNb HEAC has a single BCC solid solution structure. After the ageing treatment, the Zr<img>Al nanoprecipitates gradually formed near the grain boundaries; when the ageing time was prolonged, compared with those of Al<sub>0.3</sub>TiZrNb HEAC, the number of nanoprecipitates increased, and the grain size was obviously refined. Notably, the coating that was aged for 2 h had the greatest number of precipitates and the smallest grain size, indicating the best deformation resistance and wear resistance. Specifically, the interaction between the precipitates and high-density dislocations produced a strain-hardening effect, which enhanced the fracture toughness of the coating, changed its wear mechanism, and improved its wear resistance. This study reveals the key role of precipitation strengthening in enhancing the mechanical and wear resistance of Al<sub>0.3</sub>TiZrNb HEAC, thus increasing its potential for industrial applications.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"522 ","pages":"Article 133132"},"PeriodicalIF":6.1,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145928887","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}
Pub Date : 2025-12-29DOI: 10.1016/j.surfcoat.2025.133130
C.F. Yang , L.B. Lv , S.Q. Ding , D.X. Zhang , J.Z. Jiang , X.D. Wang , Q.P. Cao
The influences of the deposition rate (Rdep) and substrate temperatures (Tsub) on the morphology, phase structure and nanomechanical properties of AlCoCrFeNi2.1 eutectic high entropy alloy (EHEA) thin films fabricated by magnetron sputtering (MS) were systematically investigated. The surface morphology featured by a granular structure with the particle size increased from ~28.5 nm for Rdep = 0.12 nm/s to ~66.7 nm for Rdep = 4.53 nm/s. With increasing Tsub from 298 K to 673 K at Rdep = 1.28 nm/s, the particle size rose from ~43.6 nm to ~62.2 nm. The enhanced adatom surface diffusivity dominating the competition with available time effect was introduced to account for this. The phase structure evolved from fcc-dominated to bcc-dominated structure at higher Rdep and Tsub owing to the enhanced adatom diffusivity and the heterogeneous nucleation features of MS. The nanoindentation hardness (H) value increased from ~6.73 GPa to ~9.64 GPa as Rdep varied from 0.12 nm/s to 1.28 nm/s, due to the improved adhesion of nanocolumns and the increased fraction of bcc phase, then reduced to ~7.11 GPa as Rdep further rose to 4.53 nm/s due to the weakening of the Hall-Petch effect dominated in competition with the strengthening effect of bcc phases. Meanwhile, the H value also dramatically decreased from ~9.64 GPa to ~7.13 GPa as Tsub increased from 298 K to 573 K with Rdep = 1.28 nm/s due to the increased grain size, and further increased to ~7.87 GPa with Tsub = 673 K owing to the precipitation strengthening of nano-sized σ phase. The designable dual-phase structure shows remarkable potential in balancing strength and plasticity, making it suitable for fabricating protective gas turbine blade coatings.
{"title":"Modulable microstructure and nanomechanical property of AlCoCrFeNi2.1 eutectic high entropy alloy thin films","authors":"C.F. Yang , L.B. Lv , S.Q. Ding , D.X. Zhang , J.Z. Jiang , X.D. Wang , Q.P. Cao","doi":"10.1016/j.surfcoat.2025.133130","DOIUrl":"10.1016/j.surfcoat.2025.133130","url":null,"abstract":"<div><div>The influences of the deposition rate (<em>R</em><sub>dep</sub>) and substrate temperatures (<em>T</em><sub>sub</sub>) on the morphology, phase structure and nanomechanical properties of AlCoCrFeNi<sub>2.1</sub> eutectic high entropy alloy (EHEA) thin films fabricated by magnetron sputtering (MS) were systematically investigated. The surface morphology featured by a granular structure with the particle size increased from ~28.5 nm for <em>R</em><sub>dep</sub> = 0.12 nm/s to ~66.7 nm for <em>R</em><sub>dep</sub> = 4.53 nm/s. With increasing <em>T</em><sub>sub</sub> from 298 K to 673 K at <em>R</em><sub>dep</sub> = 1.28 nm/s, the particle size rose from ~43.6 nm to ~62.2 nm. The enhanced adatom surface diffusivity dominating the competition with available time effect was introduced to account for this. The phase structure evolved from fcc-dominated to bcc-dominated structure at higher <em>R</em><sub>dep</sub> and <em>T</em><sub>sub</sub> owing to the enhanced adatom diffusivity and the heterogeneous nucleation features of MS. The nanoindentation hardness (<em>H</em>) value increased from ~6.73 GPa to ~9.64 GPa as <em>R</em><sub>dep</sub> varied from 0.12 nm/s to 1.28 nm/s, due to the improved adhesion of nanocolumns and the increased fraction of bcc phase, then reduced to ~7.11 GPa as <em>R</em><sub>dep</sub> further rose to 4.53 nm/s due to the weakening of the Hall-Petch effect dominated in competition with the strengthening effect of bcc phases. Meanwhile, the <em>H</em> value also dramatically decreased from ~9.64 GPa to ~7.13 GPa as <em>T</em><sub>sub</sub> increased from 298 K to 573 K with <em>R</em><sub>dep</sub> = 1.28 nm/s due to the increased grain size, and further increased to ~7.87 GPa with <em>T</em><sub>sub</sub> = 673 K owing to the precipitation strengthening of nano-sized <em>σ</em> phase. The designable dual-phase structure shows remarkable potential in balancing strength and plasticity, making it suitable for fabricating protective gas turbine blade coatings.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"522 ","pages":"Article 133130"},"PeriodicalIF":6.1,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145898177","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号