Pub Date : 2024-11-29DOI: 10.1016/j.surfcoat.2024.131603
T. Tekin , G. Ischia , F. Naclerio , R. Ipek , A. Molinari
The tensile ductility of a surface-treated 18Ni300 maraging steel produced by Laser Powder Bed Fusion (L-PBF) was investigated in the present work. Both plasma nitriding and duplex treatments (plasma nitriding and Physical Vapour Deposition (PVD) coating) were considered using a direct aged material as a reference. The inhomogeneous microstructure of the surface-treated materials causes an early strain-induced austenite transformation, with a positive effect on the uniform plastic deformation. However, the brittle failure of the hardened surface and the coating promotes an inhomogeneous stress field and inhomogeneous deformation whose effect on tensile ductility prevails on the enhanced TRansformation Induced Plasticity (TRIP), resulting in a negative overall effect on ductility.
The study's results suggest a metallurgical approach to optimizing the inhomogeneous microstructure of the surface-treated material, with the aim of preventing the decrease of ductility.
{"title":"Tensile ductility of a duplex surface treated maraging steel produced by Laser Powder Bed Fusion: Interaction between the inhomogeneous microstructure and transformation induced plasticity","authors":"T. Tekin , G. Ischia , F. Naclerio , R. Ipek , A. Molinari","doi":"10.1016/j.surfcoat.2024.131603","DOIUrl":"10.1016/j.surfcoat.2024.131603","url":null,"abstract":"<div><div>The tensile ductility of a surface-treated 18Ni300 maraging steel produced by Laser Powder Bed Fusion (L-PBF) was investigated in the present work. Both plasma nitriding and duplex treatments (plasma nitriding and Physical Vapour Deposition (PVD) coating) were considered using a direct aged material as a reference. The inhomogeneous microstructure of the surface-treated materials causes an early strain-induced austenite transformation, with a positive effect on the uniform plastic deformation. However, the brittle failure of the hardened surface and the coating promotes an inhomogeneous stress field and inhomogeneous deformation whose effect on tensile ductility prevails on the enhanced TRansformation Induced Plasticity (TRIP), resulting in a negative overall effect on ductility.</div><div>The study's results suggest a metallurgical approach to optimizing the inhomogeneous microstructure of the surface-treated material, with the aim of preventing the decrease of ductility.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"496 ","pages":"Article 131603"},"PeriodicalIF":5.3,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142756689","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 : 2024-11-28DOI: 10.1016/j.surfcoat.2024.131599
Hongkang Pan , Honghua Hu , Zhonghua Wei , Fan Yang , Zhanshuai Fan , Hailin Lu
Cathodic deposition (CD) technology, as a surface treatment technology, is widely used to prepare surface protective layers of non-valve metals. However, due to the presence of a dense oxide film on the surface of valve metal, during the CD process, this dense oxide film will hinder the contact between ions in the electrolyte and the substrate surface, making CD deposition technology unsuitable for valve metal. In this paper, valve metal AZ31 Mg alloy was first treated by micro-arc oxidation (MAO) technology, and then CD treatment was performed using ethylene glycol organic solution as electrolyte. This method not only solves the problem that CD technology cannot be applied to valve metals and successfully prepares a coating with excellent friction and corrosion resistance, but also explores a new solution as a CD electrolyte. By comparing with the samples after CD treatment in deionized water solution and the samples after MAO, the results show that after CD treatment in deionized water solution, only the porosity (8.572 %) and coefficient of friction (COF) (0.403) of the coating were improved, but after CD treatment in ethylene glycol solution, the coating surface had the lowest porosity (4.263 %), the highest hardness (265.2 HV), and the smallest COF (0.362). Electrochemical tests further showed that the sample had the lowest corrosion current density (5.6099 × 10−10 A/cm2) after CD treatment in ethylene glycol electrolyte. The coating prepared by this method can be widely used in aerospace, medical equipment and other fields due to their excellent friction and corrosion resistance, and can increase the service life of Mg alloy parts. However, this method is currently more suitable for the processing of small parts. This study not only provides a valuable strategy for improving the performance of MAO coatings, but also provides a new direction for the application of CD technology on valve metals.
{"title":"Investigation on surface properties of AZ31 magnesium alloy modified by micro-arc oxidation and cathodic deposition techniques","authors":"Hongkang Pan , Honghua Hu , Zhonghua Wei , Fan Yang , Zhanshuai Fan , Hailin Lu","doi":"10.1016/j.surfcoat.2024.131599","DOIUrl":"10.1016/j.surfcoat.2024.131599","url":null,"abstract":"<div><div>Cathodic deposition (CD) technology, as a surface treatment technology, is widely used to prepare surface protective layers of non-valve metals. However, due to the presence of a dense oxide film on the surface of valve metal, during the CD process, this dense oxide film will hinder the contact between ions in the electrolyte and the substrate surface, making CD deposition technology unsuitable for valve metal. In this paper, valve metal AZ31 Mg alloy was first treated by micro-arc oxidation (MAO) technology, and then CD treatment was performed using ethylene glycol organic solution as electrolyte. This method not only solves the problem that CD technology cannot be applied to valve metals and successfully prepares a coating with excellent friction and corrosion resistance, but also explores a new solution as a CD electrolyte. By comparing with the samples after CD treatment in deionized water solution and the samples after MAO, the results show that after CD treatment in deionized water solution, only the porosity (8.572 %) and coefficient of friction (COF) (0.403) of the coating were improved, but after CD treatment in ethylene glycol solution, the coating surface had the lowest porosity (4.263 %), the highest hardness (265.2 HV), and the smallest COF (0.362). Electrochemical tests further showed that the sample had the lowest corrosion current density (5.6099 × 10<sup>−10</sup> A/cm<sup>2</sup>) after CD treatment in ethylene glycol electrolyte. The coating prepared by this method can be widely used in aerospace, medical equipment and other fields due to their excellent friction and corrosion resistance, and can increase the service life of Mg alloy parts. However, this method is currently more suitable for the processing of small parts. This study not only provides a valuable strategy for improving the performance of MAO coatings, but also provides a new direction for the application of CD technology on valve metals.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"496 ","pages":"Article 131599"},"PeriodicalIF":5.3,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747006","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 : 2024-11-26DOI: 10.1016/j.surfcoat.2024.131596
Chaoqun Xia , Wanwan Liang , Xing Zhang , Bin Zhang , Shuguang Liu , Bohan Chen , Ning Liu , Tai Yang , Qiang Li
Zr-2.5Nb alloy is widely used as an implant material in the biomedical field. Zr-2.5Nb alloy was subjected to laser processing and laser processing combined with thermal oxidization composite treatment to investigate the effects of different structures and surface treatments on its morphology and surface element distribution, corrosion, friction properties and biocompatibility. The results show that after laser processing alone, ZrO2 and Nb2O5 appear on the surface, but the oxide film is thin, and after composite treatment, t-ZrO2 appears on the surface of the Bulge structure. Meanwhile, the corrosion resistance of the alloy in simulated body fluids is significantly improved after composite treatment, among which the LIPSS structure has the strongest corrosion resistance, and the corrosion current density is improved by two orders of magnitude in comparison with that of the substrate. The results of the wear volume experiments show that the wear resistance of both the laser treatment and its composite treatment is improved, with the LIPSS structure having the best performance. In addition, the composite treatment was shown to be biocompatible and suitable for use as an implant material.
{"title":"Enhancing wear resistance and biocompatibility of medical ZrNb alloy used for artificial joint via femtosecond laser surface processing combined with thermal oxidation","authors":"Chaoqun Xia , Wanwan Liang , Xing Zhang , Bin Zhang , Shuguang Liu , Bohan Chen , Ning Liu , Tai Yang , Qiang Li","doi":"10.1016/j.surfcoat.2024.131596","DOIUrl":"10.1016/j.surfcoat.2024.131596","url":null,"abstract":"<div><div>Zr-2.5Nb alloy is widely used as an implant material in the biomedical field. Zr-2.5Nb alloy was subjected to laser processing and laser processing combined with thermal oxidization composite treatment to investigate the effects of different structures and surface treatments on its morphology and surface element distribution, corrosion, friction properties and biocompatibility. The results show that after laser processing alone, ZrO<sub>2</sub> and Nb<sub>2</sub>O<sub>5</sub> appear on the surface, but the oxide film is thin, and after composite treatment, t-ZrO<sub>2</sub> appears on the surface of the Bulge structure. Meanwhile, the corrosion resistance of the alloy in simulated body fluids is significantly improved after composite treatment, among which the LIPSS structure has the strongest corrosion resistance, and the corrosion current density is improved by two orders of magnitude in comparison with that of the substrate. The results of the wear volume experiments show that the wear resistance of both the laser treatment and its composite treatment is improved, with the LIPSS structure having the best performance. In addition, the composite treatment was shown to be biocompatible and suitable for use as an implant material.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"496 ","pages":"Article 131596"},"PeriodicalIF":5.3,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747005","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 : 2024-11-26DOI: 10.1016/j.surfcoat.2024.131594
Marvin Sauter , Christian Semmler , Tobias Nies , Giulia Poppi , Luca Bortolotti , Filippo Ottani , Giovanni Bolelli , Luca Lusvarghi , Andreas Killinger
This study investigates the performance of Nichrome coatings, a nickel‑chromium alloy containing 20 wt.-% chromium, applied using three thermal spray techniques: powder plasma spray, suspension HVOF, and filament HVOF. Thin, homogeneous coatings approximately 35 μm thick were deposited onto steel substrates pre-coated with an insulating Al2O3 layer. The oxide content in the coatings varied based on the spraying technique and parameters, ranging from 57 to 64 vol.-% for plasma spraying, 42 to 54 vol.-% for filament HVOF, and 9 to 43 vol.-% for suspension HVOF. The coating's heating performance was evaluated over a temperature range of room temperature (RT) to 700 °C. Analytical techniques such as X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray Spectroscopy (EDS) were employed to investigate the mechanisms affecting temperature-dependent resistivity in relation to the coating microstructure. The results indicate that increased oxidation leads to a decrease in specific resistivity at RT (ρ0). In example, plasma sprayed coatings exhibited lower specific resistivity ρ0 of 0.80 Ωmm2/m. In contrast, suspension HVOF reaches values up to 2.75 Ωmm2/m. At the same time coatings with higher oxidation levels demonstrate an elevated dependence of resistivity as compared to less oxidized coatings. Both can be attributed to changes in the phase composition of the conductive phase as the dominating factor, primarily driven by the preferential oxidation of chromium during the spraying process. Notably, the results provide valuable information for adjusting the coating properties to suit specific needs, such as self-regulating or high-temperature heating applications.
{"title":"High temperature properties of nichrome resistant heaters – A systematic comparison of APS, suspension and filament HVOF sprayed coatings","authors":"Marvin Sauter , Christian Semmler , Tobias Nies , Giulia Poppi , Luca Bortolotti , Filippo Ottani , Giovanni Bolelli , Luca Lusvarghi , Andreas Killinger","doi":"10.1016/j.surfcoat.2024.131594","DOIUrl":"10.1016/j.surfcoat.2024.131594","url":null,"abstract":"<div><div>This study investigates the performance of Nichrome coatings, a nickel‑chromium alloy containing 20 wt.-% chromium, applied using three thermal spray techniques: powder plasma spray, suspension HVOF, and filament HVOF. Thin, homogeneous coatings approximately 35 μm thick were deposited onto steel substrates pre-coated with an insulating Al<sub>2</sub>O<sub>3</sub> layer. The oxide content in the coatings varied based on the spraying technique and parameters, ranging from 57 to 64 vol.-% for plasma spraying, 42 to 54 vol.-% for filament HVOF, and 9 to 43 vol.-% for suspension HVOF. The coating's heating performance was evaluated over a temperature range of room temperature (RT) to 700 °C. Analytical techniques such as X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray Spectroscopy (EDS) were employed to investigate the mechanisms affecting temperature-dependent resistivity in relation to the coating microstructure. The results indicate that increased oxidation leads to a decrease in specific resistivity at RT (<em>ρ</em><sub>0</sub>). In example, plasma sprayed coatings exhibited lower specific resistivity <em>ρ</em><sub>0</sub> of 0.80 Ωmm<sup>2</sup>/m. In contrast, suspension HVOF reaches values up to 2.75 Ωmm<sup>2</sup>/m. At the same time coatings with higher oxidation levels demonstrate an elevated dependence of resistivity as compared to less oxidized coatings. Both can be attributed to changes in the phase composition of the conductive phase as the dominating factor, primarily driven by the preferential oxidation of chromium during the spraying process. Notably, the results provide valuable information for adjusting the coating properties to suit specific needs, such as self-regulating or high-temperature heating applications.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"496 ","pages":"Article 131594"},"PeriodicalIF":5.3,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-26DOI: 10.1016/j.surfcoat.2024.131597
Atiyeh Adelinia , Aleksey Yerokhin , David T.A. Matthews , Matthijn B. de Rooij , Jamal Seyyed Monfared Zanjani
The porosity and microstructure of plasma electrolytic oxidation (PEO) coatings are key factors in determining their properties and applications. Despite advances in understanding the PEO process, the mechanisms driving pore formation and their correlation with process parameters remain unclear due to the complex interplay between these variables. This study investigates the effects of treatment time and duty cycle on the microstructure of PEO coatings produced on an aluminium alloy in an alkaline electrolyte, with a particular focus on pore formation. Our findings reveal that longer treatment durations lead to the significant development of sub-surface pores at the interface between the inner and outer layers. Additionally, a lower duty cycle leads to an increase in sub-surface pores, while a higher duty cycle favours the formation of surface pores. Morphological, 3D microstructural mapping, and chemical analyses reveal that pore formation is driven by the micro-discharges, gas generation, and the preferred gas escape path within the micro-melt pools formed during the PEO formation process. The preferred gas escape path is closely linked to the characteristics and lifetime of local micro-melt pools, elucidating the mechanisms behind pore formation.
{"title":"Pore formation and pore inter-connectivity in plasma electrolytic oxidation coatings on aluminium alloy","authors":"Atiyeh Adelinia , Aleksey Yerokhin , David T.A. Matthews , Matthijn B. de Rooij , Jamal Seyyed Monfared Zanjani","doi":"10.1016/j.surfcoat.2024.131597","DOIUrl":"10.1016/j.surfcoat.2024.131597","url":null,"abstract":"<div><div>The porosity and microstructure of plasma electrolytic oxidation (PEO) coatings are key factors in determining their properties and applications. Despite advances in understanding the PEO process, the mechanisms driving pore formation and their correlation with process parameters remain unclear due to the complex interplay between these variables. This study investigates the effects of treatment time and duty cycle on the microstructure of PEO coatings produced on an aluminium alloy in an alkaline electrolyte, with a particular focus on pore formation. Our findings reveal that longer treatment durations lead to the significant development of sub-surface pores at the interface between the inner and outer layers. Additionally, a lower duty cycle leads to an increase in sub-surface pores, while a higher duty cycle favours the formation of surface pores. Morphological, 3D microstructural mapping, and chemical analyses reveal that pore formation is driven by the micro-discharges, gas generation, and the preferred gas escape path within the micro-melt pools formed during the PEO formation process. The preferred gas escape path is closely linked to the characteristics and lifetime of local micro-melt pools, elucidating the mechanisms behind pore formation.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"496 ","pages":"Article 131597"},"PeriodicalIF":5.3,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-25DOI: 10.1016/j.surfcoat.2024.131592
Omid Bakhtiary, Shayan Sarraf, Mansour Soltanieh
Si-modified aluminide coatings are promising for improving oxidation and corrosion resistance in superalloys at high temperatures. This study investigated the effect of different silicon levels in the aluminizing slurry on the morphology and structure of Si-modified aluminide coatings on IN625. This process involved spraying a slurry of aluminum and silicon particles in an aqueous PVA solution onto IN625 samples, followed by heat treatment under controlled conditions - two atmospheres (air and argon) and two heating ramps (regular and flash). Surface morphologies, cross-sectional structures, elemental compositions, and phase formations were analyzed using FE-SEM, SEM, EDS, and XRD methods, while DTA analysis assessed AlSi alloy formation during heating. The results showed that higher silicon content in the slurry increased silicon incorporation in the coatings but did not reduce aluminum activity enough to deposit a low-activity aluminide coating. The inert atmosphere (argon) and flash heating promoted the co-deposition of Si and Al, resulting in Cr and Mo silicide-enriched outer layers in some samples. The aluminum content in all slurries was sufficient for consistent β-NiAl formation across different silicon levels. The average silicon content in coatings ranged from 5 to 15 wt% and depended on the slurry composition and heat treatment conditions. The Al30Si slurry produced the thickest coatings (~90 μm), with further increases in Si leading to reduced thickness. This study suggests that slurry aluminizing can be optimized to control silicon incorporation, depositing Si-modified aluminide coatings for durable, high-performance applications.
{"title":"Microstructure evaluation of si-modified aluminide coatings on in625 deposited by slurry aluminizing process","authors":"Omid Bakhtiary, Shayan Sarraf, Mansour Soltanieh","doi":"10.1016/j.surfcoat.2024.131592","DOIUrl":"10.1016/j.surfcoat.2024.131592","url":null,"abstract":"<div><div>Si-modified aluminide coatings are promising for improving oxidation and corrosion resistance in superalloys at high temperatures. This study investigated the effect of different silicon levels in the aluminizing slurry on the morphology and structure of Si-modified aluminide coatings on IN625. This process involved spraying a slurry of aluminum and silicon particles in an aqueous PVA solution onto IN625 samples, followed by heat treatment under controlled conditions - two atmospheres (air and argon) and two heating ramps (regular and flash). Surface morphologies, cross-sectional structures, elemental compositions, and phase formations were analyzed using FE-SEM, SEM, EDS, and XRD methods, while DTA analysis assessed Al<img>Si alloy formation during heating. The results showed that higher silicon content in the slurry increased silicon incorporation in the coatings but did not reduce aluminum activity enough to deposit a low-activity aluminide coating. The inert atmosphere (argon) and flash heating promoted the co-deposition of Si and Al, resulting in Cr and Mo silicide-enriched outer layers in some samples. The aluminum content in all slurries was sufficient for consistent β-NiAl formation across different silicon levels. The average silicon content in coatings ranged from 5 to 15 wt% and depended on the slurry composition and heat treatment conditions. The Al<img>30Si slurry produced the thickest coatings (~90 μm), with further increases in Si leading to reduced thickness. This study suggests that slurry aluminizing can be optimized to control silicon incorporation, depositing Si-modified aluminide coatings for durable, high-performance applications.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"495 ","pages":"Article 131592"},"PeriodicalIF":5.3,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699753","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 : 2024-11-23DOI: 10.1016/j.surfcoat.2024.131589
Xuyue Yao , Dexin Chen , Zhong Alan Li , Zhentao Yu
The high corrosivity of MgLi alloy limits its wide application in maritime, aerospace, electronic device, etc. Therefore, there is an urgent need for an efficient coating to effectively protect it. In this study, hexamethyldisiloxane (HMDSO) was utilized as a precursor to deposit polysiloxane films on MgLi alloy using Plasma Enhanced Chemical Vapor Deposition (PECVD) technology, aimed at improving surface properties and enhancing corrosion resistance. By adjusting the O2 flow rate, a series of films with different properties were prepared, and their structures were transitioned from organic (SiOxCyHz) to inorganic (SiOx). The test results showed that different O2 flow rates led to different deposition rates, the film thickness initially increased and then decreased. With the increase in O2 flow rate, the content of O element in the film gradually increases, the molecular chain extension of the film increases the crosslinking degree, which changes the mechanical properties and wettability. Electrochemical tests showed that the corrosion current density of the coated MgLi alloy is decreased by 5 orders of magnitude compared to the bare MgLi alloy. Additionally, in the voltage corrosion test at 10 V, the film showed good endurance against current breakdown, and the film surface was not damaged after 2 min of test.
镁锂合金的高腐蚀性限制了它在航海、航空航天、电子设备等领域的广泛应用。因此，迫切需要一种有效的涂层来对其进行有效保护。本研究以六甲基二硅氧烷（HMDSO）为前驱体，采用等离子体增强化学气相沉积（PECVD）技术在镁锂合金上沉积聚硅氧烷薄膜，旨在改善其表面性能并增强其耐腐蚀性。通过调节氧气流速，制备了一系列不同性质的薄膜，其结构也从有机（SiOxCyHz）过渡到无机（SiOx）。测试结果表明，不同的氧气流速会导致不同的沉积速率，薄膜厚度先增加后减小。随着氧气流速的增加，薄膜中 O 元素的含量逐渐增加，薄膜分子链的延伸增加了交联度，从而改变了机械性能和润湿性。电化学测试表明，涂层镁锂合金的腐蚀电流密度比裸镁锂合金降低了 5 个数量级。此外，在 10 V 的电压腐蚀测试中，薄膜显示出良好的耐电流击穿性能，测试 2 分钟后薄膜表面未受损。
{"title":"Protective polysiloxane films on MgLi alloy by PECVD: Optimized oxygen flow rate to obtain highly anti-corrosion properties","authors":"Xuyue Yao , Dexin Chen , Zhong Alan Li , Zhentao Yu","doi":"10.1016/j.surfcoat.2024.131589","DOIUrl":"10.1016/j.surfcoat.2024.131589","url":null,"abstract":"<div><div>The high corrosivity of MgLi alloy limits its wide application in maritime, aerospace, electronic device, etc. Therefore, there is an urgent need for an efficient coating to effectively protect it. In this study, hexamethyldisiloxane (HMDSO) was utilized as a precursor to deposit polysiloxane films on MgLi alloy using Plasma Enhanced Chemical Vapor Deposition (PECVD) technology, aimed at improving surface properties and enhancing corrosion resistance. By adjusting the O<sub>2</sub> flow rate, a series of films with different properties were prepared, and their structures were transitioned from organic (SiO<sub>x</sub>C<sub>y</sub>H<sub>z</sub>) to inorganic (SiO<sub>x</sub>). The test results showed that different O<sub>2</sub> flow rates led to different deposition rates, the film thickness initially increased and then decreased. With the increase in O<sub>2</sub> flow rate, the content of O element in the film gradually increases, the molecular chain extension of the film increases the crosslinking degree, which changes the mechanical properties and wettability. Electrochemical tests showed that the corrosion current density of the coated MgLi alloy is decreased by 5 orders of magnitude compared to the bare MgLi alloy. Additionally, in the voltage corrosion test at 10 V, the film showed good endurance against current breakdown, and the film surface was not damaged after 2 min of test.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"495 ","pages":"Article 131589"},"PeriodicalIF":5.3,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699752","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 : 2024-11-23DOI: 10.1016/j.surfcoat.2024.131558
Ke-ran Li , Yong Yang , Hong-jian Zhao , Wei Li , Xing-yu Wang , Yan-wei Wang , Wen-wei Sun , Yu-xuan Shao , Yu-duo Ma , Pei-wen Ru , Yong-gang Wang , Yan-chun Dong , Sheng-yong Gao
Zirconium boride composite coatings were synthesized in situ using atmospheric plasma spraying process with ZrO2-B4C-Al as precursor, and ZrB2-ZrC-Al2O3 composite coatings were prepared as a comparison, and the microstructures and thermal shock and ablation resistance of the two systems of composite coatings were studied comparatively. The results showed that the ZrO2-B4C-Al system composite coating had higher density and ultra-fine microstructure, and this coating had better thermal shock resistance, which is mainly due to the reaction between the composite powders during the in-situ formation process of the coating, resulting in higher density and more stable phase structure. In the ablation test, a large amount of Al4B2O9 was formed on the surface of the ZrB2-ZrC-Al2O3 composite coating, which played the role of stabilizing the liquid phase and covered the surface of the coating to prevent the diffusion of oxygen, and the crystals grew and arranged preferentially to form a large-grained spherical oxidized eutectic phase as well as a solid solution of alumina and zirconia, so that the coating showed excellent ablation-resistant properties.
{"title":"Thermal shock and ablation resistance of ZrB2-ZrC-Al2O3 composite coatings synthesized in situ by plasma spraying","authors":"Ke-ran Li , Yong Yang , Hong-jian Zhao , Wei Li , Xing-yu Wang , Yan-wei Wang , Wen-wei Sun , Yu-xuan Shao , Yu-duo Ma , Pei-wen Ru , Yong-gang Wang , Yan-chun Dong , Sheng-yong Gao","doi":"10.1016/j.surfcoat.2024.131558","DOIUrl":"10.1016/j.surfcoat.2024.131558","url":null,"abstract":"<div><div>Zirconium boride composite coatings were synthesized in situ using atmospheric plasma spraying process with ZrO<sub>2</sub>-B<sub>4</sub>C-Al as precursor, and ZrB<sub>2</sub>-ZrC-Al<sub>2</sub>O<sub>3</sub> composite coatings were prepared as a comparison, and the microstructures and thermal shock and ablation resistance of the two systems of composite coatings were studied comparatively. The results showed that the ZrO<sub>2</sub>-B<sub>4</sub>C-Al system composite coating had higher density and ultra-fine microstructure, and this coating had better thermal shock resistance, which is mainly due to the reaction between the composite powders during the in-situ formation process of the coating, resulting in higher density and more stable phase structure. In the ablation test, a large amount of Al<sub>4</sub>B<sub>2</sub>O<sub>9</sub> was formed on the surface of the ZrB<sub>2</sub>-ZrC-Al<sub>2</sub>O<sub>3</sub> composite coating, which played the role of stabilizing the liquid phase and covered the surface of the coating to prevent the diffusion of oxygen, and the crystals grew and arranged preferentially to form a large-grained spherical oxidized eutectic phase as well as a solid solution of alumina and zirconia, so that the coating showed excellent ablation-resistant properties.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"495 ","pages":"Article 131558"},"PeriodicalIF":5.3,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699754","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 : 2024-11-23DOI: 10.1016/j.surfcoat.2024.131593
Fan Liu , Huyue Wang , Bo Zhao , Wei Zhang , Qiang Wang , Yunsong Niu , Yu Wang , Hailong Yu , Qingchuan Wang , Ke Yang
With superior bone growth and integration abilities, porous tantalum (Ta) implants prepared by depositing Ta coating on foam carbon have been widely used in clinical for two decades. To solve their high cost and high weight disadvantages, the deposition of thin Ta coating on porous titanium (Ti) alloys substrate by chemical vapor deposition (CVD) is expected to be a promising strategy. However, until now realizing the novel strategy is still a big challenge. In this study, by the TaCl5-H2 reaction, we investigated the preparation of Ta coating on Ti6Al4V (TC4) matrix by CVD. The effects of reaction temperature and gas flow on the microstructure, composition, and properties of the Ta coating were systematically investigated. The results indicated that Ta coatings about 5 μm with high quality was successfully prepared on plane and porous TC4 for the first time, and the reaction temperature played a more important role than the gas flow. The optimal preparation parameters were determined to be 950 °C and 200 sccm. Under the condition, Ta coating with the fully α-Ta phase, high purity, high uniformity and compactness was achieved. The Ta coating exhibited excellent binding force, corrosion resistance, hydrophilicity. Through eliminating the toxic V ions dissolution from TC4, the Ta coating also obtained excellent cell compatibility, which is meaningful for porous TC4 implants widely used in clinic with very high specific surface area. Therefore, this research evidenced that, by CVD, the novel thin Ta coated porous TC4 implants with lower cost, lower weight and higher biocompatibility could be achieved.
通过在泡沫碳上沉积钽（Ta）涂层制备的多孔钽（Ta）植入物具有卓越的骨生长和整合能力，二十年来已广泛应用于临床。为了解决其成本高、重量大的缺点，通过化学气相沉积（CVD）在多孔钛（Ti）合金基底上沉积薄薄的 Ta 涂层有望成为一种前景广阔的策略。然而，到目前为止，实现这一新型策略仍是一个巨大的挑战。在本研究中，我们利用 TaCl5-H2 反应，研究了通过 CVD 在 Ti6Al4V (TC4) 基体上制备 Ta 涂层。系统研究了反应温度和气体流量对 Ta 涂层微观结构、成分和性能的影响。结果表明，首次在平面多孔的 TC4 上成功制备出了高质量的 5 μm 左右的 Ta 涂层，而且反应温度比气体流量起着更重要的作用。最佳制备参数被确定为 950 °C 和 200 sccm。在此条件下，制备出了全α-Ta 相、高纯度、高均匀性和致密性的 Ta 涂层。Ta 涂层具有优异的结合力、耐腐蚀性和亲水性。通过消除毒性 V 离子从 TC4 中的溶出，Ta 涂层还获得了极佳的细胞相容性，这对于在临床上广泛使用的具有极高比表面积的多孔 TC4 植入物来说意义重大。因此，这项研究证明，通过 CVD 技术，可以实现成本更低、重量更轻、生物相容性更高的新型薄 Ta 涂层多孔 TC4 植入体。
{"title":"Study on deposition of biomedical Ta coating on Ti6Al4V alloy substrate by CVD and its properties","authors":"Fan Liu , Huyue Wang , Bo Zhao , Wei Zhang , Qiang Wang , Yunsong Niu , Yu Wang , Hailong Yu , Qingchuan Wang , Ke Yang","doi":"10.1016/j.surfcoat.2024.131593","DOIUrl":"10.1016/j.surfcoat.2024.131593","url":null,"abstract":"<div><div>With superior bone growth and integration abilities, porous tantalum (Ta) implants prepared by depositing Ta coating on foam carbon have been widely used in clinical for two decades. To solve their high cost and high weight disadvantages, the deposition of thin Ta coating on porous titanium (Ti) alloys substrate by chemical vapor deposition (CVD) is expected to be a promising strategy. However, until now realizing the novel strategy is still a big challenge. In this study, by the TaCl<sub>5</sub>-H<sub>2</sub> reaction, we investigated the preparation of Ta coating on Ti6Al4V (TC4) matrix by CVD. The effects of reaction temperature and gas flow on the microstructure, composition, and properties of the Ta coating were systematically investigated. The results indicated that Ta coatings about 5 μm with high quality was successfully prepared on plane and porous TC4 for the first time, and the reaction temperature played a more important role than the gas flow. The optimal preparation parameters were determined to be 950 °C and 200 sccm. Under the condition, Ta coating with the fully α-Ta phase, high purity, high uniformity and compactness was achieved. The Ta coating exhibited excellent binding force, corrosion resistance, hydrophilicity. Through eliminating the toxic V ions dissolution from TC4, the Ta coating also obtained excellent cell compatibility, which is meaningful for porous TC4 implants widely used in clinic with very high specific surface area. Therefore, this research evidenced that, by CVD, the novel thin Ta coated porous TC4 implants with lower cost, lower weight and higher biocompatibility could be achieved.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"495 ","pages":"Article 131593"},"PeriodicalIF":5.3,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699761","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 : 2024-11-23DOI: 10.1016/j.surfcoat.2024.131540
Martin Matas , Paul H. Mayrhofer , David Holec
CrN belongs to a family of transition metal nitrides used as protective coatings. It has an antiferromagnetic (AFM) orthorhombic structure below the Néel temperature () and adopts paramagnetic (PM) cubic B1 above . In the past, the PM state was often wrongly approximated by a non-magnetic (NM) configuration. First-principles calculations suggested interesting mechanical properties of this hypothetical NM-CrN phase. In this work, we use density functional theory to probe the hypothesis that alloying or spatial confinement can cause local quenching of the Cr magnetic moments and, hence, stabilize the NM-CrN phase. Our calculations show that the magnetic moments are extremely robust and remain almost intact irrespective of which of the group III B to group VI B elements is alloyed. Similarly, superlattices with AlN and TiN in various thickness ratios do not reveal any quenching of the local magnetic moments. We therefore conclude that it is unlikely that material design would promote the NM-CrN phase, which thereby remains a purely hypothetical construct.
{"title":"Magnetic moments in CrN-based systems are robust: An ab initio study of alloys and superlattices","authors":"Martin Matas , Paul H. Mayrhofer , David Holec","doi":"10.1016/j.surfcoat.2024.131540","DOIUrl":"10.1016/j.surfcoat.2024.131540","url":null,"abstract":"<div><div>CrN belongs to a family of transition metal nitrides used as protective coatings. It has an antiferromagnetic (AFM) orthorhombic structure below the Néel temperature (<span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>N</mi></mrow></msub></math></span>) and adopts paramagnetic (PM) cubic B1 above <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>N</mi></mrow></msub></math></span>. In the past, the PM state was often wrongly approximated by a non-magnetic (NM) configuration. First-principles calculations suggested interesting mechanical properties of this hypothetical NM-CrN phase. In this work, we use density functional theory to probe the hypothesis that alloying or spatial confinement can cause local quenching of the Cr magnetic moments and, hence, stabilize the NM-CrN phase. Our calculations show that the magnetic moments are extremely robust and remain almost intact irrespective of which of the group III<!--> <!-->B to group VI<!--> <!-->B elements is alloyed. Similarly, superlattices with AlN and TiN in various thickness ratios do not reveal any quenching of the local magnetic moments. We therefore conclude that it is unlikely that material design would promote the NM-CrN phase, which thereby remains a purely hypothetical construct.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"496 ","pages":"Article 131540"},"PeriodicalIF":5.3,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","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