天冬聚脲涂层体系的防腐蚀性能

制备了以天冬聚脲涂料为面漆的重防腐蚀涂层体系,开展了循环盐雾试验、氙灯老化加速试验及吸水率测试。通过形貌观察、能谱分析、电化学测试、涂层厚度及附着力测试等,研究了该涂层体系的防腐蚀性能及腐蚀老化规律。结果表明：天冬聚脲面漆配套以重防腐蚀底漆和中间漆,涂层的耐盐雾腐蚀和光老化性能优异,附着力良好,吸水率低,可有效抵御湿热盐雾大气环境影响,有效防护金属基体。     

快干型高固体分环氧防腐底漆的研究

目的研制高性能快干型高固体分环氧防腐底漆。方法将低黏度高活性环氧树脂和普通环氧树脂进行复配,得到可用于高固含涂料的树脂基料;通过分子结构优化设计,合成制备了以酚醛胺改性聚酰胺树脂为主体并结合柔性长链改性胺树脂复配的固化剂体系;利用复配的环氧树脂基料、自制的固化剂体系和无铬防锈颜料等组分研制了快干型高固体分环氧底漆。根据国家标准,进行了力学性能(包括柔韧性、耐冲击性和附着力)、耐环境性能(包括耐湿热、耐盐雾性能)和耐液体介质等涂层性能测试;通过考核涂层耐丁酮擦拭100次是否露底,来表征涂层的固化,采用FTIR手段,动态跟踪环氧固化过程。结果新研制的环氧涂料具有优良的力学性能和防腐性能,涂料的固含量73%,表干时间40 min,适用期8 h,耐盐雾和湿热均能达到5000 h,全面性能已达到国外现役先进材料水平,且工艺性能良好。结论以低黏度高活性环氧树脂为基体,采用酚醛与柔性长链二聚酸改性的聚酰胺固化剂,可制备高性能快干高固体分环氧防腐底漆,在飞机的防护底漆领域具有良好的应用前景。     

银圭涂层在电力系统应用研究

本文用测试了银圭涂层的附着力、柔韧性、耐冲击性能、耐盐雾实验等,考察该涂层的性能。通过扫描电镜观察了银圭涂层盐雾实验前后的围观形貌。     

前处理方式对6016铝合金表面电泳复合涂层性能的影响

前处理+电泳处理是汽车用铝合金常用的表面处理方式,磷化处理与锆化处理是常用的前处理方式。系统对比分析了6016铝合金表面磷化+电泳复合涂层与锆化+电泳复合涂层的形貌、结构、附着力、硬度、杯突性能、耐冲击性能、电化学性能、耐丝状腐蚀性能等。结果表明：锆化处理膜层厚度在50 nm左右,磷化处理膜层厚度为2μm～3μm。锆化+电泳与磷化+电泳两种复合涂层的力学性能相当。电化学测试结果表明,锆化膜具有比磷化膜更优异的耐蚀性能,锆化处理更有益于提高6016铝合金耐丝状腐蚀性能。     

钢铁表面水性透明耐蚀涂层的研制

以苯丙乳液为主要成膜物质,利用正交试验优化各助剂用量得到了涂料的最佳配方,制备了适用于钢铁表面的水性透明耐蚀涂层.试验结果表明:该涂层具有良好的附着力、耐蚀性、耐湿热性、抗老化性、柔韧性、耐冲击性、透光性和回粘性,而且该涂料的最低成膜温度为4.9℃,可以满足钢铁在室外的防护要求.     

活载效应下钢-混凝土组合梁表面涂层的疲劳应力分析

基于等效应力原则,采用内聚力模型,通过ANSYS-Workbench在钢-混凝土组合梁受力最大处建立局部模型,分析钢-混凝土组合梁表面涂层在活载作用下的破损机理及其疲劳寿命预测。结果表明:涂层干膜厚度在210～300μm内,各层漆的拉应力从大到小依次为底漆、中间漆、面漆,各层漆的剪应力从大到小依次为中间漆、面漆、底漆,且随疲劳循环次数的增大,涂层体系越薄,面漆失效越快,抗疲劳性能越差;在只考虑活载效应时,干膜厚度为210μm时面漆的疲劳寿命约为20.9 a;干膜厚度为300μm时,面漆的疲劳寿命可达26.6 a。     

抗菌防霉防腐阻燃一体化纳米涂层应用研究

目的通过特种功能纳米粒子的协同作用以及不同功能涂层的合理配套使用,获得集抗菌防霉、防腐、阻燃和耐磨等多种功能于一体,适用于涉海和航天装备综合防护的多功能纳米涂层材料。方法以环氧树脂为底漆和中间漆的基体树脂,加入多聚磷酸盐和石墨烯复合助剂制备防腐底漆,加入石墨烯和膨胀型阻燃剂为复合阻燃助剂制备阻燃中间漆;以丙烯酸改性聚氨酯为面漆基体树脂,加入吡啶硫酮锌和纳米银抗菌复合助剂以及纳米陶瓷颗粒耐磨助剂,制备抗菌防霉耐磨聚氨酯面漆。将防腐底漆、阻燃中间漆和抗菌防霉耐磨面漆合理搭配,制备多功能一体化综合防护涂层材料。通过铅笔硬度测试、划格法附着力测试、耐冲击强度测试和耐人工老化测试评价纳米涂层的常规性能,通过盐雾测试研究防腐性能,通过燃烧实验研究阻燃性能,通过抗菌防霉实验研究抗菌防霉性能,通过摩擦实验评价其耐磨性能。结果经测试,纳米涂层的硬度为H,附着力为0级,耐冲击强度为50 kg·cm。800 h人工老化试验后,漆膜无明显变化。800 h中性盐雾测试后,基体无腐蚀点。12 s垂直燃烧实验研究发现其平均烧焦长度仅为1 mm,滴落物的续燃时间为0 s。烟密度研究发现纳米涂层240 s的Dm平均值仅为13,抗菌、防霉实验表明该纳米涂层对大部分细菌的抑菌率高达99%,其防霉等级为0级,耐磨性能测试发现涂层的质量损失为32 mg。结论所研制的一体化纳米涂层具有优异的防腐、阻燃、耐磨和抗菌防霉性能,可以在航天航空以及海工设施等特种设备上使用,能够起到综合防护作用。     

涂层结构对建筑节能涂层性能的影响

目的通过探究建筑节能涂层的最佳涂层结构,进而提升涂层的隔热和耐久性能。方法将含空心微珠和二氧化钛的涂层作底漆,硅溶胶-苯丙复合涂层作面漆,探究不同种类底漆和面漆对铬绿建筑节能涂层性能的影响。采用正交试验寻求最佳底漆和面漆组合方案,对最佳组合方案涂层进行了综合性能测试,并探讨了相关机理。结果在不改变涂层颜色外观的情况下,底漆可增加涂层的太阳光反射比,面漆可增大涂层的静态接触角,增强涂层的耐水性、耐沾污性和耐老化性,降低涂层污染后和人工气候老化后太阳光反射比变化率及色差。最佳涂层结构组合方案为:底漆中空心微珠和二氧化钛掺量均为5%,面漆中苯丙乳液和硅溶胶质量比为14∶1。此时涂层的太阳光反射比和隔热温差分别为0.6455和6.9℃,且综合性能均较好,具有一定的应用价值。结论涂层结构对建筑节能涂层的隔热和耐久性能具有一定的影响,实际应用时可根据需要改变涂层结构来获得满意的性能。     

铝合金与复合材料组合构件的涂装工艺

目的解决底/面漆涂层在铝合金与复合材料基材表面经常出现剥离、起泡、开裂等缺陷问题。方法通过对问题涂层部件的结构设计合理性分析,指出了封闭式蒙皮结构部件出现的设计缺陷。对铝合金与复合材料的加工工艺进行了分析,用对比试验的方法,验证了铝合金阳极氧化处理工艺所生成的保护膜对涂层性能的影响。通过改进表面前处理工艺,验证了复合材料表层残留的脱模剂是影响涂层附着力的主要原因。以改善涂层应力变化适应能力为目的,调整了涂料韧性配方,涂覆不同的基材和相关结构部件,用可模拟产品试验考核状态的"温度冲击+振动+湿热"联合加载试验方法,验证了设计与工艺改进后的涂层性能。结果合理设计通气孔后,消除了封闭式蒙皮结构部件内部气体的膨胀效应,改进铝合金与复合材料表面前处理工艺和涂料韧性后,涂层不再出现起层开裂现象。结论封闭式蒙皮结构部件应设置内外通气工艺孔,彻底清除复合材料表面脱模剂渗透层和铝合金表面的阳极氧化膜,选用韧性好的涂料体系,能够有效提升铝合金与复合材料组合构件表面涂层的环境适应性能。     

氟碳涂层对海洋环境下混凝土抗氯离子渗透性能的影响

目的研究不同氟碳涂层体系对海洋环境下混凝土抗氯离子渗透性能的影响规律及作用机理。方法以溶剂型氟碳涂层和水性氟碳涂层为研究对象,开展了两种溶剂型氟碳涂层体系和一种水性氟碳涂层体系的研究,即环氧底漆-溶剂型氟碳面漆、环氧底漆-聚氨酯中层漆-溶剂型氟碳面漆及水性环氧底漆-水性氟碳面漆。通过氯离子电迁移快速试验,研究涂覆这三种氟碳涂层体系的混凝土抗氯离子渗透性能。采用干湿循环试验模拟浪花飞溅区,通过混凝土抗氯离子侵蚀试验及扫描电镜观察试验,研究涂层对混凝土在海洋环境浪花飞溅区的防腐性能。结果氯离子电迁移快速试验测得的氯离子扩散系数表明,氟碳涂层体系作用下,混凝土氯离子扩散系数降低。干湿循环试验36 d后,通过扫描电镜观察发现这两种溶剂型氟碳涂层体系表面仍然致密,水性氟碳涂层体系表面出现裂缝。结论溶剂型和水性氟碳涂层体系均能提高混凝土抗氯离子渗透性,溶剂型氟碳涂层体系在海洋浪花飞溅区更耐久,更适用于该环境下的混凝土腐蚀防护。     

Mechanical Properties of TiN Coating on Nanocrystalline Surface Layer of 304 Stainless Steel

Surface nanocrystallization(SNC)can markedly improve surface mechanical properties of metallic materials and accelerate thermal diffusion of elemental atoms.In this work we study the effects of SNC on structure and mechanical properties of TiN coating on 304 stainless steel substrate.The steel was subjected to 15 min surface mechanical attrition treatment(SMAT)to obtain a nanocrystalline surface layer with thickness about 30μm.TiN coating was deposited on the surface nanocrystallized and the coarse-grained steel substrates by multi-arc ion plating.X-ray diffraction shows that TiN(111)orientation of the coating is much reduced due to SNC treatment.Mechanical tests show that the nanocrystalline surface layer has obviously increased surface hardness of the coating system;toughness and adhesion of the coating,impact resistance of the coating system are also improved.Advantages of SNC-hard coating processing over the conventional duplex treatment consisting of thermal diffusion process-hard coating are shortly discussed.     

Application of embedded sensors in the thermal cycling of organic coatings

A standard Air Force polyurethane topcoat/epoxy chromate pigmented primer system was characterized using the thermal cycling method. This method is an accelerated test method for organic coatings that involves exposing the coating to alternating room temperature and elevated temperature cycles under constant immersion. Electrochemical properties were monitored using electrochemical impedance spectroscope for the total topcoat/primer system, the inner layer of primer, and the outer layer of the topcoat. The individual layers were monitored using platinum sensors embedded between the layers. Characterization of a system comprising of two layers of the epoxy chromate pigmented primer was also performed using EIS monitoring, and embedded sensors. The systems were cycled between room temperature, and set temperatures up to 80 °C. The barrier property of the topcoat and the bulk resistance of the primer were consistent with Arrehenius behavior. The results obtained were consistent with the intended design of the polyurethane topcoat and chromate primer with the former providing the significant barrier protection, whereas the primer providing the passivating chromate to the metal/coating interface. Analysis of the EIS data obtained from the sensor with an equivalent circuit decoupled the bulk primer properties from the metal/coating interface properties.     

纳米TiO2在汽车面漆中的应用研究

阐述了纳米TiO2对汽车面漆性能的影响机理,提出了利用纳米TiO2提高汽车面漆耐老化性的设想,制定了纳米TiO2涂料的配方,并研究分析了纳米TiO2对汽车面漆性能的影响规律.通过实验对漆膜的光泽度、附着力、冲击强度、硬度、耐水性、耐老化性等进行检测,当纳米TiO2的加入量为1.0%～2.0%时,涂层的耐老化性能平均提高20%左右,其光泽度也有所提高,而附着力、冲击强度、硬度、耐水性提高不明显.     

碳纳米管复合水性丙烯酸涂层的腐蚀性能研究

目的制备碳纳米管复合水性丙烯酸涂层,探索分析碳纳米管含量对涂层力学和防腐性能的影响规律。方法采用高速球磨方式制备3%,1%,0.5%三种含量(以质量分数计)的碳纳米管复合涂层,对涂层附着力、耐冲击性、耐弯曲性等力学性能进行测试,以电化学阻抗技术来评价碳纳米管复合涂层的防腐性能。结果添加碳纳米管显著提高了涂层的附着力,并且随着碳纳米管含量的增加,附着力上升;其他力学性能,如耐冲击性、耐弯曲性,在不同含量下均保持良好。对改性和未改性的涂层进行了电化学阻抗测试,其中1%的碳纳米管涂层电化学性能最优,在浸泡36 h后,未改性涂层低频区阻抗模值|Z|0.01为2.5×103Ω·cm2,0.5%的碳纳米管涂层为1.1×106Ω·cm2,1%的为1.4×108Ω·cm2,3%的为7×102Ω·cm2。结论由于碳纳米管本身的纳米效应,在较低含量时即可提高涂层的性能,并存在最优含量,超过此含量后性能有所下降。     

树脂基复合材料表面修整工艺材料性能研究

目的为提高复合材料涂装前的喷漆表面平整度,保证漆膜表面状态。方法分别采用表面修整剂、针孔填充剂和封孔剂等三种工艺材料,对玻璃纤维增强树脂基复合材料表面进行喷漆前的表面修整,并涂装配套的防护底漆。通过对修整材料的固化性能、与基材及漆层的表面结合力以及涂层系统相容性等性能进行测试,并与未使用工艺材料进行表面修整处理的复合材料喷漆后的表面状态进行对比,评价三种工艺材料的工艺性能、附着力及与涂层的相容性等。结果在树脂基复合材料表面,涂装前配套使用针孔填充剂和封孔剂或针孔填充剂和表面修整剂进行表面修整,可有效降低复合材料表面针孔、凹坑等缺陷对涂装外观的影响,且漆层与基底的结合力大于15 MPa,与未使用工艺材料的涂层系统比较,性能未下降。结论三种工艺材料与底面漆的相容性良好,对涂层力学性能及耐介质性能无不良影响,可配套用于复合材料涂装前的表面修整,提升涂装表面状态。     

Recent Developments in the Field of Thermal Barrier Coatings

Conventional thermal barrier coating (TBC) systems consist of a duplex structure with a metallic bondcoat and a ceramic, heat-isolative topcoat. Several recent research activities are concentrating on developing improved bondcoat or topcoat materials; for the topcoat especially, those with reduced thermal conductivity are investigated. Using advanced topcoat materials, the ceramic coating can be further divided into layers with different functions. One example is the double-layer system in which conventional yttria-stabilized zirconia (YSZ) is used as bottom and new materials such as pyrochlores or perovskites are used as topcoat layers. These systems demonstrated an improved temperature capability compared to standard YSZ. In addition, new functions are introduced within the TBCs. These can be sensorial properties that can be used for an improved temperature control or even for monitoring remaining lifetime. Further increased application temperatures will also lead to efforts for a further improvement of the reflectivity of the coatings to reduce the radiative heat transfer through the TBC.     

Effect of SiC whiskers on the oxidation protective properties of SiC coatings for carbon/carbon composites

In order to effectively employ the unique high temperature mechanical properties of carbon/carbon composite substrates, SiC coatings reinforced by SiC whiskers were prepared by pack cementation method. The effect of SiC whiskers on the oxidation resistance properties of the single-layer coating and double-layer coating was investigated. SiC whiskers in the single-layer SiC coating have little effect on the anti-oxidation property but obviously improve the thermal shock property. The double-layer coating with inner-layer reinforced coating exhibits more perfect anti-oxidation ability than the double-layer coating with SiC inner-layer coating.     

Resonant-based identification of the elastic properties of layered materials: Application to air-plasma sprayed thermal barrier coatings

This work introduces a resonant-based, mixed numerical–experimental method for the determination of the in-plane elastic properties of the constituent materials of laminates. This non-destructive method identifies elastic properties from the resonant frequencies of beam-shaped layered specimens, using a set of finite element models. The method is demonstrated on a thermal barrier coating system made of NiCoCrAlY bondcoat and yttria-stabilised zirconia topcoat deposited by air-plasma spraying on stainless steel. The stainless steel was found to be elastically anisotropic, while both bondcoat and topcoat exhibited in-plane isotropy. Moreover, the topcoat Poisson's ratio approached zero, and the bondcoat properties varied with the coating thickness. Scanning electron microscopy was used to correlate the identified elastic properties with the coating microstructure.     

Anticorrosive effectiveness of coatings with reduced content of Zn pigments in comparison with zinc-rich primers

ABSTRACT

Typically, an anticorrosive coating system for long-term protection consists of a primer, one or several intermediate coats, and a topcoat. In such systems, zinc-rich primers are often used as they ensure good adhesion to the substrate and protect it from corrosion. Such coatings are very highly pigmented, which sometimes leads to losses in cohesive strength and deterioration of mechanical properties. Furthermore, Zn is known to be harmful to the environment. In this work we present Zn primers with reduced Zn content and better protective properties than traditional zinc-rich primers. The formulations of different Zn pigments in the epoxy matrix were developed with the concentration of zinc particles reduced to about 50% in the dry coating. To evaluate the distribution of pigments scanning electron microscopy has been employed. The anticorrosive properties were tested using the salt spray test and electrochemical impedance spectroscopy. The mechanical properties of the coatings were also tested.