Preparation technology and anti-corrosion performances of black ceramic coatings formed by micro-arc oxidation on aluminum alloys

In order to prepare ornamental and anti-corrosive coating on aluminum alloys, preparation technology of black micro-arc ceramic coatings on Al alloys in silicate based electrolyte was studied. The influence of content of Na2WO4 and combination additive in solution on the performance of black ceramic coatings was studied; the anticorrosion performances of black ceramic coatings were evaluated through whole-immersion test and electrochemical method in 3.5% NaCl solution at different pH value; SEM and XRD were used to analyze the surface morphology and phase constitutes of the black ceramic coatings. Experimental results indicated that, without combination additives, with the increasing of Na2WO4 content in the electrolyte, ceramic coating became darker and thicker, but the color was not black; after adding combination additive, the coating turned to be black; the black ceramic coating was multi-hole form in surface. There was a small quantity of tungsten existing in the black ceramic coating beside α-Al2O3 phase and β-Al2O3 phase. And aluminum alloy with black ceramic coating exhibited excellent anti-corrosion property in acid, basic and neutral 3.5% NaCl solution.

Investigation of anti-corrosion property of hybrid coatings fabricated by combining PEC with MAO on pure magnesium

Novel hybrid coatings on pure magnesium were prepared by combining plasma electrolytic carburizing(PEC)with micro-arc oxidation(MAO)to further enhance the anti-corrosion property in this paper.Scanning electron microscopy(SEM)was used to observe the microstructure of the coatings,meanwhile,energy dispersive spectrometry(EDS)and X-ray diffraction(XRD)were separately used to investigate the elemental as well as phase compositions of the coatings.The anti-corrosion property of the coatings was evaluated by potentiodynamic polarization curves as well as electrochemical impedance spectroscopy(EIS).The results show that PEC process is closely related with the effects of adsorption as well as diffusion of the activated carbon atoms,and it can provide a favorable pretreatment surface with predesigned chemical composition to obtain a new kind of phase,namely Si C with superior corrosion resistance and chemical stability,in the following PEC+MAO hybrid coatings.Meanwhile,PEC preprocessing also can afford an excellent micro-structure to increase the coating thickness as well as to improve the compactness of the PEC+MAO hybrid coatings.During the fabrication process of the PEC+MAO hybrid coatings,an overlapping phenomenon in regard to coating thickness can be observed instead of heaping up layer by layer.Compared with both single PEC surface modification layers as well as single MAO coatings,the PEC+MAO hybrid coatings exhibit more superior anti-corrosion property.Especially,the EIS data reveal that the PEC+MAO hybrid coatings can act as an effective protection system to provide relatively excellent long-range anti-corrosion protection.Note also that employing same MAO technique for both single MAO treatment as well as PEC+MAO combining procedure is the key to this research.

An electrochemical method for evaluating the resistance to cathodic disbondment of anti-corrosion coatings on buried pipelines

Methods for evaluating the resistance to cathodic disbondment （RCD） of anti-corrosion coatings on buried pipelines were reviewed. It is obvious that these traditional cathodic disbondment tests （CDT） have some disadvantages and the evaluated results are only simple figures and always rely on the subjective experience of the operator. A new electrochemical method for evaluating the RCD of coatings, that is, the potentiostatic evaluation method （PEM）, was developed and studied. During potentiostatic anodic polarization testing, the changes of stable polarization current of specimens before and after cathodic disbonding （CD） were measured, and the degree of cathodic disbondment of the coating was quantitatively evaluated, among which the equivalent cathodic disbonded distance AD was suggested as a parameter for evaluating the RCD. A series of testing parameters of the PEM were determined in these experiments.

Influence of graphene on the anti-corrosion performance of epoxy-based coatings

In this work, graphene-modified epoxy-based anti-corrosion coatings were prepared and the influence of graphene on the anti-corrosion performance of the epoxy-based coatings was investigated with water contact angle test ,chemical solution immersion test, and electrochemical test. The water contact angle and chemical solution resistance of the epoxy-based coatings were improved with an increase in graphene content from 0 to 0.4%. These results prove that addition of graphene can significantly improve the hydrophobicity and impermeability of epoxy- based coatings. However, when the graphene content was increased to 0.5%, the performance of the epoxy-based coatings decreased because of graphene aggregation. Tafel polarization results show that graphene addition can significantly reduce the corrosion current density and corrosion potential of epoxy-based coatings, which enhance their anti-corrosion performance.

The Effect of Cerium Dioxide (CeO_2) in an Anti-corrosion and Self-lubricating Coating

The effect of cerium dioxide(CeO_2)as an additive on the structure and properties of a melting type coating has been studied by means of microhardness measurement,scanning electron microscopy and thermal analysis. The results show that cerium dioxide can modify the microstructure and tribological properties of the coating. Model LIC-23 composite coating which contains CeO_2 performs well as a self-lubricating coating in hydrochloric acid solution.

An Abrasion Resistant TPU/SH-SiO_(2) Superhydrophobic Coating for Anti-Icing and Anti-Corrosion Applications

As a passive anti-icing strategy,properly designed superhydrophobic coatings can demonstrate outstanding performances.However,common preparation strategies for superhydrophobic coatings often lead to environmental pollution,high energy-consumption,high-cost and other undesirable issues.Besides,the durability of superhydrophobic coating also plagues its commercial application.In this paper,we introduced a facile and environment-friendly technique for fabricating abrasion-resistant superhydrophobic surfaces using thermoplastic polyurethane(TPU)and modified SiO_(2)particles(SH-SiO_(2)).Both materials are non-toxicity,low-cost,and commercial available.Our methodology has the following advantages:use of minimal amounts of formulation,take the most streamlined technical route,and no waste material.These advantages make it attractive for industrial applications,and its usage sustainability can be promised.In this study,the mechanical stability of the superhydrophobic surface was evaluated by linear wear test.It is found that the excellent wear resistance of the superhydrophobic coating benefits from the characteristics of raw materials,the preparation strategy,and the special structure.In anti-icing properties test,the TPU/SH-SiO_(2)coating exhibits the repellency to the cold droplets and the ability to extend the freezing time.The electrochemical corrosion measurement shows that the asprepared superhydrophobic surface has excellent corrosion resistance that can provide effective protection for the bare Q235 substrates.These results indicate that the TPU/SH-SiO_(2)coating possesses good abrasion resistance and has great potential in anti-corrosion and anti-icing applications.

A novel anti-corrosion coating for magnesium alloy

A novel enviromental protective water based metallic coating were prepared on the surface of AZ91D magnesium alloy. The properties and structure of the coating were investigated by adhension test, hardness test, heat resisting test, neutral salt spray test and scanning electron microscopy (SEM). The results show that the coating has a stepped structure which can achieve good adhesion of first-grade, heat resistance temperature of 400℃, hardness of HV_ 0.50/30210 and anti-corrosion time of 250h in salt spray test. Meanwhile, the film forming and corrosion mechanism of the coating were also put forward based on the results of the Fourier transform infrared spectroscopy (FTIR) test and electrochemical impedance spectroscopy (EIS) test.

Cerium Methacrylate Assisted Preparation of Highly Thermally Conductive and Anticorrosive Multifunctional Coatings for Heat Conduction Metals Protection

Preparing polymeric coatings with well corrosion resistance and high thermal conductivity(TC)to prolong operational life and ensure service reliability of heat conductive metallic materials has long been a substantive and urgent need while a difficult task.Here we report a multifunctional epoxy composite coating(F-CB/CEP)by synthesizing cerium methacrylate and ingeniously using it as a novel curing agent with corrosion inhibit for epoxy resin and modifier for boron nitride through"cation-π"interaction.The prepared F-CB/CEP coating presents a high TC of 4.29 W m^(−1)K^(−1),which is much higher than other reported anti-corrosion polymer coatings and thereby endowing metal materials coated by this coating with outstanding thermal management performance compared with those coated by pure epoxy coating.Meanwhile,the low-frequency impedance remains at 5.1×10^(11)Ωcm^(2)even after 181 days of immersion in 3.5 wt%NaCl solution.Besides,the coating also exhibits well hydrophobicity,self-cleaning properties,temperature resistance and adhesion.This work provides valuable insights for the preparation of high-performance composite coatings with potential to be used as advanced multifunctional thermal management materials,especially for heat conduction metals protection.

Development of anti-corrosive coating on AZ31 Mg alloy subjected to plasma electrolytic oxidation at sub-zero temperature

Plasma electrolytic oxidation(PEO)is a promising surface treatment to generate adherent and thick anti-corrosive coating on light-weight metals(Al,Mg,Ti,etc.)using an eco-friendly alkaline electrolyte.High energy plasma,however,inevitably generates porous structures that limit their practical performance.The present study proposes a straight-forward simple method by utilizing sub-zero electrolyte(268 K)to alter the plasma characteristics during formation of the protective coating on AZ31 Mg alloy via PEO with a comparison to the electrolyte at room temperature(298 K).In refrigerated electrolyte,the formation of micro-defects is suppressed relatively at the expense of low coating growth,which is measured to be twice lower than that at 298 K due to the temperature-dependent soft plasma discharges contributing to the development of the present coating.As a consequence,corrosion resistance of the sample processed at 268 K is superior to that of 298K,implying that the effect of coating thickness is less dominant than that of compactness.This phenomenon is interpreted in relation to the ionic movement and oxide solidification controlled by soft plasma discharges arising from the temperature gradient between electrolyte and surface of the substrate during PEO.

Bonding strength of graded anti-corrosive coatings of fluoroethylenepropylene (FEP)/polyphenylene sulfide (PPS)

Fluororesin-based anti-corrosive coatings including graded FEP/PPS were prepared on carbon steel by melt powder coating, the bonding strength of all coating systems was determined by the pull-off test. It is found that the poor adhesion of fluororesin coatings to metallic substrates is improved obviously by the graded coating structure of FEP/PPS, and the bonding strength reaches up to 11.8 MPa for the five-layer system. Examination by electron probe microanalysis （EPMA） verifies that the distribution of main components is graded in the five-layer system, which is responsible for the enhancement of the interfacial bonding.

Recent Progress in Superhydrophobic Coatings Using Molecular Dynamics Simulations and Experimental Techniques

Superhydrophobic(SH)coatings are intended to resist a surface from cor­rosion and thereby increases the product life duration.It is also a promising solution to save cleaning costs and time by providing self-clean nature to the surface.This review article provides the most recent updates in design­ing SH surfaces and their characterizations adopted both in experimental and computational techniques.To gain a comprehensive perspective,the SH surfaces present in nature those are inspiring human beings to mimic such surfaces are introduced at the beginning of this article.Subsequently,different fabrication techniques undertaken recently to design artificial SH surfaces are briefly discussed.Recent progress in computations employed in the development of SH surfaces is then discussed.Next,the limitations in SH surfaces are addressed.Finally,perceptiveness of different strategies and their limitations are presented in the concluding remarks and outlook.Overall,this mini review article brings together and highlights the significant advancements in fabrication of superhydrophobic surfaces which may surely help the early-stage researchers/scientists to plan their work accordingly.

Coated fabrics covering sales outlook, demand forecast & up-to-date key trends

Coated fabrics market to grow at 5.1%CAGR through 2031.Coated fabrics are woven or non-woven cloth with a specialized coating that's applied to the surface of the material,or saturated into the material's bulk.The coating is usually a polymer or elastomer that imparts particular properties,such as resistance to water,mildew,or sunlight.

加工专用型双青大豆齐农绿1号的选育研究

随着特用型双青大豆商品原料需求量日益增多,现有双青豆品种的商品产出量不能满足生产和市场需要,尤其是双青豆新品种的更新换代速度与育成数量不及普通类型品种,现有生产应用的品种相对单一,老品种在生产上连年种植,种性退化,对病虫草害的抵抗能力减弱,造成产量和品质降低,有碍于双青大豆产业的健康发展。针对存在的问题,黑龙江省农业科学院齐齐哈尔分院大豆研究团队开展了双青大豆育种工作,选育出双青大豆齐农绿1号,该品种属特用型绿种皮绿子叶大豆品种。适宜在黑龙江省第四积温带≥10℃活动积温2250℃区域种植,在适应区出苗至成熟生育日数113 d左右。株高89 cm左右,有分枝,白花、尖叶、亚有限结荚习性,灰色茸毛,荚弯镰形、成熟时呈褐色,籽粒圆形、种皮绿色有光泽,种脐褐色,百粒重20.6 g左右。2020—2021年区域试验平均产量2630.4 kg·hm^(-2),较对照品种广石绿大豆1号增产9.8%;中抗灰斑病;平均蛋白质含量39.39%,脂肪含量20.04%。该品种的育成,既为特用型双青大豆生产提供新品种支撑,满足市场对新品种的需求,提升品种对产业的贡献度,又为双青大豆育种特供优异的亲本资源,拓宽了遗传基础,加快了双青大豆新品种的培育速度。

基于随机森林回归的船舶特涂维修的日能耗预测

特殊涂装(简称特涂)维修是修船工作的核心内容,能耗的预测是船舶智能能效优化中的一项重要任务。使用随机森林回归(RFR)模型对船舶特涂维修日能耗进行分析,去除异常值、随机化和标准化数据集,然后使用RFR模型对船舶日能耗历史数据进行训练拟和,利用带交叉验证的网格搜索优化RFR模型,使用优化后的RFR模型对船舶特涂维修日能耗数据进行分析,并与其他模型进行对比实验。结果表明,优化后的RFR模型预测效果优于多种其他模型,R2值达93.25%,均方误差明显更低。

航空特种涂料的发展应用探讨

重点介绍了隐身涂料、耐高温涂料和抗静电涂料等航空特种涂料的国内外研制进展及应用情况,分析了特种涂料对航空维修的影响,为航空维修企业提供参考。

基于环保政策探讨专用汽车的涂装工艺选择

环保低碳化、智能化转型是专用汽车制造工艺发展的方向,专用汽车涂装工艺的选择首先要满足环保政策法规的要求,同时要兼顾成本和质量效率的要求。本文归纳了与专用汽车行业有关的国家和地方环境保护政策、法律和标准要求,对水性涂装和粉末涂装进行了对比分析,并给出了选择建议。

硅氧烷改性聚醚胺固化剂对环氧连接漆的性能影响研究

为了解决低表面能防污面漆与常规防腐底漆之间匹配应用性能较差的问题,利用低表面能防污面漆的物理特性及活性基团特征,制备硅氧烷改性聚醚胺固化剂;以常规环氧连接漆配方为基础,通过探讨硅氧烷改性聚醚胺固化剂对连接漆的微观形貌、邵氏A型硬度、静态水接触角、附着强度的影响,确定专用连接漆中硅氧烷改性聚醚胺固化剂的添加量;将专用连接漆与低表面能防污面漆结合后,测试了体系的FIIR谱,对体系进行了耐甲苯/氨溶液浸泡和浅海浸泡性能测试,探究了专用连接漆的界面反应机理及实海应用性能。结果表明:硅氧烷改性聚醚胺固化剂的胺氢当量为200~300,旋转黏度为180~250 mPa·s(25℃),硅氧烷改性聚醚胺固化剂可显著提高专用连接漆的自流平性能、降低邵氏A型硬度、增大静态水接触角、增强各漆膜间的相容性;当硅氧烷改性聚醚胺固化剂添加质量分数为6%时,可实现与防污面漆的最佳连接效果,附着强度达2.1 MPa左右,且相互间为稳定牢固的化学键合,浅海浸泡试验结果明显优于常规环氧连接漆。本研究结果可有效解决低表面能防污面漆与底漆之间的配套问题,延长防腐防污涂层整体的使用寿命。

药物球囊预扩联合支架置入治疗椎动脉狭窄患者中专项管理方案的构建与应用

目的 研究药物球囊联合支架置入治疗椎动脉狭窄患者中专项管理方案的构建及应用效果。方法 纳入2020年1月至2021年6月收治的椎动脉狭窄行药物球囊预扩联合支架置入治疗的患者共计96例为研究对象。将患者以数字表法随机分为观察组与对照组,每组48例。对照组实施常规管理方案,观察组实施专项管理方案,对比不同管理方案对2组患者临床康复效果的影响。结果 干预后观察组上消化道出血率、住院费用均低于对照组(P<0.05),住院时间短于对照组(P<0.05);干预前2组患者三酰甘油、胆固醇与低密度脂蛋白水平无明显差异(P>0.05),干预后观察组指标水平均低于对照组(P<0.05);干预后观察组患者服药依从率与运动锻炼依从率显著高于对照组(P<0.05);干预前2组患者生活质量及家庭亲密度与适应性量表得分均无明显差异(P>0.05),干预后观察组患者上述量表得分均高于对照组(P<0.05);干预前2组患者焦虑与抑郁量表得分均无明显差异(P>0.05),干预后观察组患者焦虑与抑郁量表得分均低于对照组(P<0.05);连续随访1年,观察组患者椎动脉再狭窄率低于对照组(P<0.05)。结论 在接受药物球囊预扩联合支架置入术治疗的椎动脉狭窄患者中应用专项管理方案能够改善患者的临床指标,降低血脂指标水平与再狭窄率,提升患者生活质量、心理状况及家庭功能。

特殊基材用绝缘粉末涂料的应用研究

针对当下特殊基材的使用场景及性能要求,通过对环氧树脂和固化体系的改性复配,对填料及助剂的选择,探究适用于特殊基材用的绝缘粉末涂料。最终研制出解决特殊基材附着力、高低温冲击等问题,同时兼具绝缘、耐温、阻燃等性能的特殊基材用绝缘粉末涂料。

特种功能涂料的发展

综述了特种功能涂料的品类及作用机理,阐述了近年来在部分领域具有代表性和开发潜力的特种功能涂料,并提出了特种功能涂料未来的发展方向。