Co-reporter:Qingbiao Li, Wenbin Yang, Cancan Liu, Daoai Wang, Jun Liang
Surface and Coatings Technology 2017 Volume 316(Volume 316) pp:
Publication Date(Web):25 April 2017
DOI:10.1016/j.surfcoat.2017.03.021
•The properties of MAO coatings are determined by growth mechanism.•The coating growth mechanism is influenced by electrolytes.•Silicate and phosphate electrolytes are comparatively studied.•The outward growth and inward growth are emphasized.In this work, the correlations between the growth mechanism and properties of micro-arc oxidation (MAO) coatings on titanium (Ti) alloy were studied using different electrolytes. The adhesion and tribological properties of MAO coatings were evaluated by thermal shock tests and ball-on-disk friction tests, respectively. Results show that the growth mechanism as well as adhesion and tribological properties of MAO coatings are greatly influenced by electrolytes. In silicate electrolyte, the growth of MAO coatings is dominated by the deposition of silicate oxides and mostly characterized by outward growth. As a result, the coatings exhibit poor adhesion, but the presence of silicate oxides in the coatings is beneficial for improving the wear resistance. In phosphate electrolyte, the coating growth mainly results from the oxidation of the substrate and is more characterized by inward growth, resulting in high adhesion but low wear resistance. Employing the mixed silicate and phosphate electrolyte, however, is a feasible way of optimization to get relatively both high adhesion and improved wear resistance.
Co-reporter:Wenbin Yang, Qingbiao Li, Weimin Liu, Jun Liang, Zhenjun Peng, Baixing Liu
Vacuum 2017 Volume 144(Volume 144) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.vacuum.2017.08.003
•A desirable aluminate electrolyte is used to prepare PEO coating on low carbon steel.•Micropores are blocked by reaction products.•The PEO coating is of dense structure and high hardness.•The wear and corrosion resistance of low carbon steel are significantly improved.Plasma electrolytic oxidation (PEO) coating was prepared from aluminate electrolyte on low carbon steel. The structure, composition, microhardness, anti-wear and anti-corrosion properties of the PEO coating were explored. The results show that the PEO coating possesses a uniform and dense structure and is mainly composed of α-Al2O3 as well as some γ-Al2O3 and Fe3O4. The PEO coating exhibits lower friction coefficient and wear rate than that of uncoated low carbon steel under dry sliding condition. The corrosion potential of coated sample shifts toward positive direction by 380 mV and the corrosion current density decreases by 2 orders of magnitude. Therefore, the PEO coating prepared from aluminate electrolyte can offer a good protection to low carbon steel from wear and corrosion.
Co-reporter:Ruixue Kang, Zhenjun Peng, Baixing Liu, Daoai Wang, Jun Liang
Surface and Coatings Technology 2017 Volume 309() pp:67-74
Publication Date(Web):15 January 2017
DOI:10.1016/j.surfcoat.2016.11.029
•Hierarchically structured Cu layer on Al alloy was obtained from ChCl-EG solution.•Deposition rate of electroless Ni-P was accelerated by the Cu layer.•This would be a simple protocol for fast electroless Ni-P at medium-low temperature.•Cu pretreatment can maintain or marginally improve performance of Ni-P coatings.•The Cu immersion layer would be an alternative method for Al alloy pretreatment.Electroless Ni-P coating is helpful to improve the corrosion resistance and mechanical properties of the Al alloys. However, the electroless Ni-P plating is usually operated at higher temperature (above 80 °C, even up to 90 °C) in order to achieve appropriate deposition rate. Herein it is demonstrated that a novel Cu immersion layer on Al alloy with a hierarchical structure can significantly accelerate the electroless Ni-P process in a wide range of temperature. The hierarchically structured Cu layer is deposited on Al alloy through galvanic replacement deposition from an environment-friendly deep eutectic solvent comprising choline chloride and ethylene glycol. The hierarchical structure of Cu immersion layer strongly affects the nucleation and growth of Ni-P, which is beneficial for enhancing the deposition rate of electroless process. This protocol might be of interest in the fast fabrication of electroless Ni-P deposition on Al alloys at medium and low temperature (50 °C ~ 70 °C).
Co-reporter:Ruiqian Li, Yuanyuan Hou, Jun Liang
Applied Surface Science 2016 Volume 367() pp:449-458
Publication Date(Web):30 March 2016
DOI:10.1016/j.apsusc.2016.01.241
Highlights
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Ni-SiO2 nanocomposite coatings were prepared in deep eutectic solvents without any additives.
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DES is more beneficial for the co-deposition of SiO2 nanoparticles than aqueous electrolyte.
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The addition of SiO2 changed the composition and morphology of the Ni coatings.
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The corrosion resistance of Ni-SiO2 nanocomposite coating is much better than that of pure Ni.
Co-reporter:Cancan Liu, Qingbiao Li, Jun Liang, Jiansong Zhou and Lingqian Wang
RSC Advances 2016 vol. 6(Issue 36) pp:30642-30651
Publication Date(Web):18 Mar 2016
DOI:10.1039/C5RA27010C
An attempt has been made to improve the corrosion behavior of WE43 magnesium alloy by laser surface melting (LSM) using a 10 kW continuous-wave CO2 laser. The microstructure evolution of WE43 alloy after LSM treatment was analyzed by using scanning electron microscopy, energy-dispersive spectroscopy and metallographic microscope. The corrosion resistance of specimens was assessed by electrochemical and immersion tests. Results showed that the LSM treated WE43 alloy presented a uniform microstructure with refined grains, enriched alloying elements and redistributed intermetallic compounds. The LSM treatment effectively improved corrosion resistance of WE43 alloy, which was mainly associated with enrichment of alloying elements in α-Mg matrix and uniform distributions of the refined Mg14Nd2Y phase.
Co-reporter:Cancan Liu, Jun Liang, Jiansong Zhou, Qingbiao Li, Zhenjun Peng and Lingqian Wang
RSC Advances 2016 vol. 6(Issue 74) pp:70343-70351
Publication Date(Web):18 Jul 2016
DOI:10.1039/C6RA17481G
Plasma electrolytic oxidation (PEO) was performed on a laser surface melting (LSM) modified AZ91 Mg alloy. The effect of LSM pre-treatment on the long-term corrosion resistance of the PEO coated AZ91 alloy was evaluated. Results showed that the LSM pretreatment had a negligible effect on the phase composition and microstructure of the PEO coatings. However, after LSM pretreatment, the long-term corrosion resistance of the PEO coated AZ91 alloy revealed a large enhancement. This was mainly ascribed to the improved corrosion resistance of the substrate resulting from the change of microstructure characteristics induced by the LSM treatment. This provided an alternative approach to improve the long-term corrosion resistance of the PEO coated Mg alloy by appropriate surface modified pretreatment of substrates.
Co-reporter:Cancan Liu, Jun Liang, Jiansong Zhou, Qingbiao Li, Lingqian Wang
Applied Surface Science 2016 Volume 382() pp:47-55
Publication Date(Web):30 September 2016
DOI:10.1016/j.apsusc.2016.04.047
Highlights
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Laser surface melting and plasma electrolytic oxidation were used on AZ31 alloy.
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The microstructure, composition and corrosion behavior of specimens were analyzed.
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Effect of laser surface melting on corrosion behavior of specimens was evaluated.
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A model of two different corrosion mechanisms was established.
Co-reporter:Cancan Liu, Jun Liang, Jiansong Zhou, Qingbiao Li, Zhenjun Peng, Lingqian Wang
Surface and Coatings Technology 2016 Volume 304() pp:179-187
Publication Date(Web):25 October 2016
DOI:10.1016/j.surfcoat.2016.07.021
•Profuse micro-sized β-phases precipitated in T6-treated AZ91 alloy.•AZ91 alloy had better corrosion resistance after T6 treatment.•T6 treatment improved the corrosion resistance of PEO coated AZ91 alloy.AZ91 Mg alloy was treated by solid solution and ageing heat treatment (T6), followed by plasma electrolytic oxidation (PEO). The microstructure and corrosion behavior of the T6, PEO and T6-PEO treated AZ91 alloy as well as the as-received one were investigated using scanning electron microscopy, X-ray diffraction and corrosion tests, respectively. The chemical compositions of the naturally formed oxide film on sample surface were determined by X-ray photoelectron spectroscopy. Especially, the effect of T6 treatment on the corrosion behavior of the bare and PEO treated specimens was evaluated. Results showed that the T6 treatment resulted in the formation of high density fine β-phase in α-Mg matrix and enhanced the corrosion resistance of AZ91 alloy. Meanwhile, the T6-PEO treated alloy had much better corrosion resistance than the PEO treated one, due to the combined effects of reduced defects of PEO coating and improved corrosion resistance of the T6 treated substrate.
Co-reporter:RenHui Zhang, Juan Zhao, Jun Liang
Surface and Coatings Technology 2016 Volume 299() pp:90-95
Publication Date(Web):15 August 2016
DOI:10.1016/j.surfcoat.2016.05.001
•The PTFE nanoparticles were successfully inserted into PEO coating forming PTFE/PEO composite coating.•The composite coating exhibited good hydrophobicity, tribological properties and corrosion resistance.•The preparation method opens a new way to fabricate the PTFE/PEO composite coating.The PTFE-containing PEO (PTFE/PEO) composite coating is fabricated on aluminium alloy by the one-step method. The composite coating integrates the advantages of wear resistance of PEO coating and a low friction coefficient and excellent corrosion resistance of polytetrafluoroethylene. Inspection of SEM, XRD and FT-IR analysis indicates that PTFE nanoparticles could effectively seal the pores of the PEO coating. The PTFE/PEO composite coating exhibits good tribological properties. And the potentiodynamic polarization and salt spray tests reveal that the composite coating was successful in providing superior corrosion resistance to aluminium alloy.
Co-reporter:Wenbin Yang, Qingbiao Li, Qian Xiao, Jun Liang
Progress in Organic Coatings 2015 Volume 89() pp:260-266
Publication Date(Web):December 2015
DOI:10.1016/j.porgcoat.2015.09.003
•Carbon steel samples were pretreated by plasma electrolytic oxidation (PEO).•Samples with and without PEO pretreatment were coated by polyurethane (PU).•The cross-sections before and after corrosion test were observed by scanning electron microscope(SEM).•The anticorrosive performance of coatings were studied by ac/dc/ac electrochemical impedance spectroscopy.Employing pretreatment is a pressing need for preparing anticorrosive coatings on carbon steels. However, conventional pretreatments are usually based on Cr, P and some other toxic elements, which are harmful to human body. For this reason, green and environmental techniques attract more and more attention. In this paper, plasma electrolytic oxidation (PEO) process was used as a pretreatment to fabricate an underlayer for the organic coating on low carbon steel. The anticorrosive performance of the organic coated samples with and without PEO pretreatment was studied by potentiodynamic polarization, ac/dc/ac electrochemical impedance spectroscopy, salt spray and immersion tests, respectively. Results show that the PEO process produces an oxide layer with porous and rough surface structure on the low carbon steel substrate. The porous and rough PEO layer is beneficial for enhancing the adhesion strength and thickness of the organic topcoatings. The organic coated sample with PEO pretreatment exhibits improved corrosion resistance and longer service life in corrosive environment compared to that without PEO pretreatment.
Co-reporter:Ruiqian Li, Qingwei Chu and Jun Liang
RSC Advances 2015 vol. 5(Issue 56) pp:44933-44942
Publication Date(Web):11 May 2015
DOI:10.1039/C5RA05918F
In this paper, a choline chloride (ChCl)/ethylene glycol (EG) based deep eutectic solvent (DES) without any stabilizing additives was used as electrolyte to electrodeposit Ni matrix composite coatings containing either micro or nano-sized SiC particles. The electrochemical behavior of Ni in the presence of micro or nano-sized SiC particles was investigated. The effects of particle concentration, current density and stirring rate on the content of micro or nano-sized SiC particles incorporated into the Ni matrix were investigated. The microstructure, microhardness and tribological property of pure Ni and Ni matrix composite coatings containing micro or nano-sized SiC particles were compared. Results showed that the addition of micro or nano-sized SiC particles have significant effects on the nucleation mechanism of Ni in ChCl/EG DES. Micro and nano-sized SiC particles uniformly incorporated into the composite coatings, the content of SiC particles embedded in Ni coatings depends on the deposition parameters and particle size, and the maximum content of SiC in composite coatings can achieve 12.80 wt% and 5.37 wt%, respectively. Compared with the pure Ni coating, the microhardness and wear resistance of Ni–SiC composite coatings are significantly improved and the Ni matrix composite coatings containing nano-sized SiC particles exhibited better tribological property than that containing the micro-sized SiC particles.
Co-reporter:Ruiqian Li, Jun Liang, Yuanyuan Hou and Qingwei Chu
RSC Advances 2015 vol. 5(Issue 75) pp:60698-60707
Publication Date(Web):09 Jul 2015
DOI:10.1039/C5RA11577A
In this work, novel zinc–graphene oxide (Zn–GO) composite coatings were successfully prepared by pulse electrodeposition in choline chloride (ChCl)/urea based deep eutectic solvent (DES). The GO sheets exhibited excellent dispersion stability in ChCl:2urea DES without stabilizing additives and were uniformly deposited in the Zn matrix. The surface morphology and textured structure of the Zn–GO composite coatings were quite different from those of pure Zn coating, owing to the effects of GO on the electrochemical deposition behavior of Zn(II). The Zn–GO composite coatings showed higher stability and better corrosion resistance than the pure Zn coating and the corrosion resistance of Zn–GO composite coatings increased with the increase of the GO concentration.
Co-reporter:Cancan Liu, Jun Liang, Jiansong Zhou, Lingqian Wang, Qingbiao Li
Applied Surface Science 2015 Volume 343() pp:133-140
Publication Date(Web):15 July 2015
DOI:10.1016/j.apsusc.2015.03.067
Highlights
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Laser surface melting was used on AM60B Mg alloy.
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The microstructure, composition and corrosion behavior of the as-received and LSM treated specimens were compared.
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The laser treated alloy exhibited better corrosion resistance than the as-received one in the long term.
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A model of two different corrosion mechanisms was established.
Co-reporter:Fengxia Wu, Jun Liang, Weixue Li
Journal of Magnesium and Alloys 2015 Volume 3(Issue 3) pp:231-236
Publication Date(Web):September 2015
DOI:10.1016/j.jma.2015.08.004
Mg(OH)2/graphene oxide (GO) composite film was electrochemical deposited on AZ91D magnesium alloys at constant potential. The characteristics of the Mg(OH)2/GO composite film were investigated by scanning electron microscope (SEM), energy-dispersive X-ray spectrometry (EDS), X-ray diffractometer (XRD) and Raman spectroscopy. It was shown that the flaky GO randomly distributed in the composite film. Compared with the Mg(OH)2 film, the Mg(OH)2/GO composite film exhibited more uniform and compact structure. Potentiodynamic polarization tests revealed that the Mg(OH)2/GO composite film could significantly improve the corrosion resistance of Mg(OH)2 film with an obvious positive shift of corrosion potential by 0.19 V and a dramatic reduction of corrosion current density by more than one order of magnitude.
Co-reporter:Qingwei Chu, Jun Liang, Jingcheng Hao
Electrochimica Acta 2014 Volume 115() pp:499-503
Publication Date(Web):1 January 2014
DOI:10.1016/j.electacta.2013.10.204
•The electrodeposition behavior of Zn-Co alloy in ChCl/urea ionic liquid was studied.•The co-deposition process of Zn-Co alloys in ionic liquid is normal type.•The nucleation mechanism of Zn-Co alloy is an instantaneous process.•The composition, structure and morphology of Zn-Co alloys were potential dependent.The electrodeposition behavior of zinc-cobalt (Zn-Co) alloy was investigated in choline chloride/urea (1:2 molar ratio) deep eutectic solvent containing 0.11 M ZnCl2 and 0.01 M CoCl2. Cyclic voltammetry revealed that Co reduced preferably with respect to Zn and anomalous codeposition of Zn-Co did not occur in this solvent. Chronoamperometric investigations combined with field emission scanning electron microscopy (FE-SEM) indicated that the electrodeposition of Zn-Co alloys followed the mechanism of instantaneous nucleation. Energy dispersive spectroscopy (EDS), grazing incidence X-ray diffraction (GI-XRD) and SEM results showed that the deposition potential influenced the compositions, phase structure and surface morphology of the Zn-Co alloys.
Co-reporter:Qingbiao Li, Jun Liang, Baixing Liu, Zhenjun Peng, Qing Wang
Applied Surface Science 2014 Volume 297() pp:176-181
Publication Date(Web):1 April 2014
DOI:10.1016/j.apsusc.2014.01.120
Highlights
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The PEO coating growth rate increased with the cathodic voltage increasing.
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Higher cathodic voltage resulted in more compact coating structure.
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The compact structure led to low surface roughness and high wear resistance.
Co-reporter:Xiangtai Zhang, Jun Liang, Baixing Liu, Zhenjun Peng
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2014 Volume 454() pp:113-118
Publication Date(Web):20 July 2014
DOI:10.1016/j.colsurfa.2014.04.029
•Three-dimensional zinc deposits was obtained in choline chloride based ionic liquid.•Superhydrophobic surface was fabricated on zinc deposits by PP modification.•The superhydrophobic surface improved the anticorrosion properties of zinc deposits.•Anticorrosion was improved mainly due to obstruct the diffusion of Cl− on surface.A superhydrophobic composite layer was successfully fabricated via an electrochemical deposition process and subsequently modified with a polypropylene (PP) film. The surface morphologies and chemical compositions were investigated using scanning electron microscope (SEM) equipped with energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD) and Fourier-transform infrared (FT-IR), respectively. The results showed that the PP modified zinc deposits had much higher water content angle (170° ± 2°) than the zinc deposits (120° ± 2°), presenting the wettability behavior from hydrophobic to superhydrophobic performance. The anticorrosion of the superhydrophobic surface was also examined. The findings revealed that the superhydrophobic surface significantly improved the anticorrosion performance of the zinc deposits.
Co-reporter:Qingwei Chu, Jun Liang, Jingcheng Hao
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2014 Volume 443() pp:118-122
Publication Date(Web):20 February 2014
DOI:10.1016/j.colsurfa.2013.10.055
•A superhydrophobic coating was fabricated on magnesium alloy by a facile method.•The super-hydrophobic coating provided good corrosion protection to the magnesium alloy.•The surface exhibited a large contact angle after immersion test, finger pressing, and abrasion with sandpaper.A super-hydrophobic surface was successfully fabricated on magnesium alloy by electrodeposition of Zn–Co coating from choline chloride-based ionic liquid and subsequent surface modification. The water contact angle (CA) was measured to be as high as 152̊. Based on surface analysis by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared (FTIR), the super-hydrophobicity can be attributed to both the rough and porous micro- and nano-scale binary structural Zn–Co coating and surface enrichment of low surface energy stearic acid (SA). The corrosion behavior was investigated with potentiodynamic polarization measurements and it was found that the super-hydrophobic coating considerably improved the corrosion resistant performance of magnesium alloy in 0.1 mol/L NaCl solution. In addition, the stability of the super-hydrophobic property was investigated by immersion in aqueous solution, finger touching and abrasion with sandpaper. The results showed that the super-hydrophobic coating exhibited high stability in aqueous solution, the rough surface textures were retained and the coating still exhibited a large contact angle after mechanical destroy.
Co-reporter:Qingwei Chu, Wei Wang, Jun Liang, Jingcheng Hao, Zisheng Zhen
Materials Chemistry and Physics 2013 Volume 142(2–3) pp:539-544
Publication Date(Web):15 November 2013
DOI:10.1016/j.matchemphys.2013.07.049
•A non-anomalous codeposition process of Zn–Co alloys was observed in ChCl–urea IL.•High Co content Zn–Co alloy was deposited from high Co2+ concentration ChCl–urea IL.•The high Co content Zn–Co deposit was dense, homogenous and nanocrystallized.Zinc–cobalt (Zn–Co) alloys were electrodeposited from a choline chloride-based ionic liquid containing ZnCl2 and different concentration of CoCl2. It was found that the Co content in deposits increased with the increase of the concentration of Co2+ in the plating bath and the codeposition of Zn–Co alloy was a non-anomalous type, i.e. more noble metal Co depositing preferentially with respect to the less noble one Zn. Structural and composition analysis revealed that the concentration of Co2+ strongly affected the morphology and chemical content, as well as the phase structure of Zn–Co alloys. A high Co content (over 60 wt.%), dense, homogenous and nanocrystallized Zn–Co alloy was deposited from plating bath containing higher concentration of Co2+.
Co-reporter:Ming Mu, Jun Liang, Xinjian Zhou, Qian Xiao
Surface and Coatings Technology 2013 Volume 214() pp:124-130
Publication Date(Web):15 January 2013
DOI:10.1016/j.surfcoat.2012.10.079
A MoS2-containing oxide coating on Ti6Al4V alloy was prepared by one-step plasma electrolytic oxidation (PEO) process in a MoS2-dispersed phosphate electrolyte. The composition and microstructure of the oxide coatings produced in the electrolytes with and without the addition of MoS2 were analyzed by X-ray diffractometer (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS). Results showed that the MoS2 particles can be successfully incorporated into the oxide coating during the PEO process and were preferentially located in the micropores. The ball-on-disk sliding tests indicated that MoS2-containing oxide coating registered much lower friction coefficient and wear rate than the oxide coating without MoS2 under dry sliding condition. The improved tribological property of the MoS2-containing oxide coating was also discussed.Highlights► A TiO2/MoS2 composite coating on Ti alloy was prepared by one-step PEO process. ► MoS2 particles were nonuniformly distributed in the TiO2 coating. ► The TiO2/MoS2 composite coating exhibited good low-friction behavior.
Co-reporter:Renhui Zhang, Jun Liang, Qing Wang
Applied Surface Science 2012 Volume 258(Issue 10) pp:4360-4364
Publication Date(Web):1 March 2012
DOI:10.1016/j.apsusc.2011.12.113
Abstract
In this work, an electrically conductive, corrosion resistant graphite-dispersed styrene-acrylic emulsion composite coating on AZ91D magnesium alloy was successfully produced by the method of anodic deposition. The microstructure, composition and conductivity of the composite coating were characterized using optical microscope (OM), scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR) and four electrode volume resistivity instrument, respectively. The corrosion resistance of the coating was evaluated using potentiodynamic polarization measurements and salt spray tests. It is found that the graphite-dispersed styrene-acrylic emulsion composite coating was layered structure and displayed good electrical conductivity. The potentiodynamic polarization tests and salt spray tests reveal that the composite coating was successful in providing superior corrosion resistance to AZ91D magnesium alloy.
Co-reporter:Ming Mu, Xinjian Zhou, Qian Xiao, Jun Liang, Xiaodi Huo
Applied Surface Science 2012 Volume 258(Issue 22) pp:8570-8576
Publication Date(Web):1 September 2012
DOI:10.1016/j.apsusc.2012.05.051
Abstract
One-step plasma electrolytic oxidation (PEO) process in a graphite-dispersed phosphate electrolyte was used to prepare a graphite-containing oxide composite coating on Ti6Al4V alloy. The composition and microstructure of the oxide coatings produced in the phosphate electrolytes with and without addition of graphite were analyzed by X-ray diffractometer (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The tribological properties of the uncoated Ti6Al4V alloy and oxide coatings were evaluated using a reciprocating ball-on-disk tribometer. Results showed that the graphite-containing oxide composite coating can be successfully produced on Ti6Al4V alloy in the graphite-dispersed phosphate electrolyte using PEO process. The graphite-containing oxide composite coating registered much lower friction coefficient and wear rate than the uncoated Ti6Al4V alloy and the oxide coating without graphite under dry sliding condition, exhibiting excellent self-lubricating property.
Co-reporter:Lingqian Wang, Jiansong Zhou, Jun Liang, Jianmin Chen
Surface and Coatings Technology 2012 206(13) pp: 3109-3115
Publication Date(Web):
DOI:10.1016/j.surfcoat.2011.12.040
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