环氧粉末涂层对金属基材附着力的影响因素

环氧粉末涂料具有附着力好、耐腐蚀性强、耐温性能好等优点,在金属防腐特别是重防腐领域应用非常广泛。在环氧粉末涂层的诸多性能中,涂层对基材的附着力是非常重要的一项技术指标,也是满足其他性能的基础,附着力的好坏直接影响着涂层对基材的保护寿命。本文主要从喷涂温度、基材表面处理的表面粗糙度以及粉末涂料原材料等方面讨论了环氧涂层对金属基材表面附着力的影响因素。研究表明:喷涂温度提高有利于涂层附着力的提高,表面粗糙度提高且锚纹深度相对均匀有利于涂层附着力的提高,填料以及助剂的种类对附着力具有一定的影响。     

激光和等离子处理对复合材料表面涂层附着力的影响研究

为了提高环氧涂料在纤维增强聚丙烯复合材料上的附着力,采用激光和等离子体表面前处理方法,应用超景深显微镜、粗糙度测定仪、接触角测试仪以及附着力测试仪,研究了激光和等离子体表面处理对纤维增强聚丙烯复合材料表面形貌、表面粗糙度和表面水接触角的影响,并且探究了这 2种表面处理方式对环氧涂层在复合材料上附着力的影响。结果表明： 2种处理方式均可明显提高环氧涂层在基材上的附着力,附着力均可由不到 1 MPa提高至 8 MPa以上。     

激光和等离子体处理对复合材料表面涂层附着力的影响研究

为了提高环氧涂料在纤维增强聚丙烯复合材料上的附着力,采用激光和等离子体表面前处理方法,应用超景深显微镜、粗糙度测定仪、接触角测试仪以及附着力测试仪,研究了激光和等离子体表面处理对纤维增强聚丙烯复合材料表面形貌、表面粗糙度和表面水接触角的影响,并且探究了这2种表面处理方式对环氧涂层在复合材料上附着力的影响。结果表明:2种处理方式均可明显提高环氧涂层在基材上的附着力,附着力均可由不到1 MPa提高至8 MPa以上。     

金属管道内涂层—环氧粉末涂料及静电涂装工艺的研究

四、表面处理管道内防腐蚀涂层的有效寿命,在很大程度上取决于涂装前表面除锈的质量。适当的除锈质量等级和粗糙度,能使涂层有良好的附着力。通常环氧粉末涂料要求处理后的金属表面清洁度(除锈等级)应达到美国NACE标准的近白金属级,或瑞典SiS标准的Sa2.5级。粗糙度根据涂层厚度而定,最大不超过涂层厚度的2/3。钢管内表面处理主要有喷砂除锈、酸洗除锈和钢丝刷除锈等几种。其中以喷砂     

民机铝合金蒙皮的激光织构化处理

采用波长为1064 nm的激光表面处理设备在2024-T3铝合金表面刻蚀出平行线、正方形和菱形这3种织构表面。采用扫描电子显微镜与激光共聚焦显微镜观察了不同织构表面的微观形貌。通过测量对水和甘油的接触角来评价它们的浸润性。用拉脱法测试了其表面环氧涂层的附着力。结果表明,在单位面积能量密度相同的情况下,表面织构为正方形和菱形的试样表面粗糙度由处理前的1.9μm分别提升至7.6μm和7.9μm,表现出更好的浸润性,环氧涂层的附着力比未处理试样提高了70%左右,而平行线织构表面的涂层附着力只提高了24%。通过金相观察、强度失效分析及硬度测试发现,织构化处理对飞机蒙皮的力学性能基本没有影响。     

磨料质量对钢材表面清理质量的影响

我们使用磨料来清理钢材表面的目的是为了使涂层具有良好的附着力，因此清理后的钢材表面必须达到一定的清洁度（如：很彻底清理级（Sa2．5）和最彻底清理级（Sa3）等）和粗糙度要求。磨料本身的质量对表面清洁度和表面粗糙度的影响是决定性的。使用粒度合适的磨料才能获得所需要的表面粗糙度，而要获得理想的表面清洁度，磨料必须具有清除表面上所有杂质（包括铁锈、氧化皮、旧涂层等）的能力。另外，磨料本身必须是清洁的，不会对被清理表面造成污染。因此，使用磨料清理钢材表面前，我们必须对磨料的质量进行必要的检查。     

前处理清洁度对涂装维修后涂层附着力的影响

设计了不同前处理清洁度等级的钢板,并模拟桥梁工程涂装维修工况,用环氧底漆和低表面处理环氧底漆分别制备了标准试样、模拟锈蚀试样、模拟维修试样及模拟维修时返锈试样,采用划格法及拉开法测试了盐雾试验前与盐雾试验144 h和240 h后涂层的附着力,分析了不同试样的附着力变化情况.结果表明,维修涂装前处理清洁度对涂层的附着力有...     

粗糙度对彩色涂层与基体间附着力的影响

研究粗糙度对基体和涂层之间的附着力的影响,其一,是因为基体表面的凸凹不平导致漆膜在其上附着时产生互相咬合的现象,增大了附着力;另外,基体表面粗糙度越大其真实表面积越大,在基体表面发生腐蚀时腐蚀产物不易扩散,因此涂层附着力不易下降。     

附着力促进剂对铝阴极板表面环氧涂层性能的影响

为了探究附着力促进剂对铝阴极板表面环氧涂层性能的影响,本文通过拉拔实验、盐雾实验、硫酸锌浸泡实验以及交流阻抗测试,系统研究了磷酸酯类和硅烷偶联剂类附着力促进剂对环氧涂层附着力和耐腐蚀性的影响。结果表明：附着力促进剂可以明显提升环氧涂层和铝基材的结合力,添加 3%附着力促进剂 2063的涂层附着力最优,可以达到 12. 85 MPa,破坏类型以层间破坏为主;但是交流阻抗图谱显示其低频区的阻抗值比附着力促进剂 4512的低 2个数量级,通过盐雾实验和硫酸锌浸泡实验也可以看出附着力促进剂 4512可以显著提升环氧涂层的耐腐蚀性能。为平衡涂层附着力和耐腐蚀性能,通过将附着力促进剂 2063与 4512按质量比 2∶1进行复配,其附着力和耐腐蚀性可以满足要求,附着力可以达到 14. 4 MPa。     

SMC制件上单组分水性底漆附着力的影响因素

就SMC（片状模塑料复合材料）片材配方、制件表面张力、制件表面粗糙度及制件过程使用的脱模剂对SMC制件表面单组分水性底漆附着力的影响进行了试验。结果表明,SMC片材配方、制件表面粗糙度及外喷脱模剂对单组分水性底漆附着力均有直接影响。给出了一些提高涂层附着力的建议。     

Adhesion improvement of RF-sputtered alumina coatings as determined by the scratch test

One of the most important problems to overcome in the production of coatings, a major technology in surface modification, is the maximization of coating to substrate adhesion. In spite of its limitations, the scratch technique is most used in adhesion characterization studies. In this study, the adhesion of alumina coatings deposited by RF magnetron sputtering on AISI M2 high speed steel (HSS) was evaluated by the scratch test. An attempt to improve the adhesion of the alumina coatings was investigated by the deposition of an intermediate layer of Ti or TiN. The influence of the substrate surface roughness, the intermediate layer thickness, and the sputter etch cleaning on the coating adhesion was studied.     

Corrosion stability of polyester coatings on steel pretreated with different iron–phosphate coatings

The influence of steel surface pretreatment with different types of iron–phosphate coatings on the corrosion stability and adhesion characteristics of polyester coatings on steel was investigated. The phosphate coating was chemically deposited either from the simple novel plating bath, or with the addition of NaNO₂, as an accelerator in the plating bath. The morphology of phosphate coatings was investigated using atomic force microscopy (AFM). The corrosion stability of polyester coatings on steel pretreated by iron–phosphate coatings was investigated by electrochemical impedance spectroscopy (EIS) in 3% NaCl solution, while “dry” and “wet” adhesion were measured by a direct pull-off standardized procedure. It was shown that greater values of pore resistance, R_p, and smaller values of coating capacitance of polyester coating, C_c, on steel pretreated with iron–phosphate coating were obtained, as compared to polyester coating on steel phosphated with accelerator, and on the bare steel. The surface roughness of phosphate coating deposited on steel from the bath without accelerator is favorable in forming stronger bonds with polyester coating. Namely, the dry and wet adhesion measurements are in accordance with EIS measurements in 3% NaCl solution, i.e. lower adhesion values were obtained for polyester coating on steel phosphated with accelerator and on the bare steel, while the iron–phosphate pretreatment from the novel bath enhanced the adhesion of polyester coating on steel.     

Effect of vanadium additive and phosphating time on anticorrosion,morphology and surface properties of ambient temperature zinc phosphate conversion coatings on mild steel

An attempt has been made to investigate the effect of phosphating time and vanadium additive on the anticorrosion and surface properties of ambient temperature zinc phosphate coatings. Zinc phosphate coatings with different phosphating times and vanadium concentrations were applied to low carbon steel samples. A potentiostatic polarization test in 3.5 wt% NaCl solution was carried out to investigate the electrochemical properties of coated samples. Field emission scanning electron microscopy, energy-dispersive spectroscopy, and atomic force microscopy were utilized to evaluate the microstructure, chemistry and roughness of coatings. Surface properties such as wettability, surface tension, and work of adhesion were measured. Results indicate that the sample which was immersed for 30 min in the phosphating bath exhibits the lowest corrosion current density, one tenth of bare steel, due to formation of a compact coating while having a low number of microcracks. Addition of 500 ppm vanadium to the coating in a secondary bath decreases the corrosion rate of zinc phosphate coating remarkably, by almost 80%. Microstructural results reveal that vanadium-rich precipitates are formed and enhance the coating coverage on the steel substrate. Vanadium addition increases the surface roughness, surface free energy, and work of adhesion of the phosphate coating.     

A study of the effect of surface pre-treatment on the adhesion of coatings

This paper deals with the study of effects of mechanical surface preparation on the adhesion of coating with high content of zinc dust. Five kinds of mechanically blasted surfaces were studied. The following were used as abrasives: steel shot, steel grit, brown corundum oxide and zirblast. The last surface type was modified by MBX Blaster technology (mechanical bristle blasting). The surfaces topography was quantified by a roughness profilometer. The shape and size of the incurred inequalities on the modified surfaces were studied using 3D microscope images of the surface. The purity of the surfaces after pre-treatment was evaluated by impurity glued on the tape and measuring the reflection of light from the surface. Fractal analysis was used to evaluate the diversity of inequalities on the prepared surfaces. Cross-sections were also taken of the prepared surfaces. The prepared surfaces were coated with zinc-filled coating. The adhesion of the coating to the substrate was evaluated by a pull-off test after curing the coating (as sprayed), as well as after exposure to severe corrosive environments. The best adhesion of the coating was found for the coating applied to the substrate which had been pre-treated with brown corundum and steel grit.     

Effect of Cu strike coating on adhesion between Cu–Sn coated steel and rubber

In order to improve the adhesion between steel and rubber, a novel coating deposition technique has been developed, where steel substrate with orchestrated surface roughness was coated with double-layer coatings consisting of a thin Cu strike layer followed by a Cu–Sn layer with varying Sn compositions by immersion route. Coating surface characteristics studied using scanning electron microscope coupled with energy dispersion spectroscopy analyzer, electron probe micro analyzer, and inductively coupled plasma optical emission spectroscopy showed improvement in surface coverage with coating after employing the strike layer coating attributed to the better coating penetration in the deep roughness troughs. Peel test of the coated samples vulcanized with styrene butadiene rubber (SBR) was carried out which showed improvement in adhesion strength of the double-layer-coated samples inferring more uniform Cu-sulfide layer formation at interface due to more uniform coating coverage in these samples. Highest peel strength with uniform cohesive fracture within rubber was observed for optimum 2–3?wt% Sn content in the coatings. This result was further supported by pull-out test conducted on coated wire samples vulcanized with SBR.     

Role of Sn on the adhesion in Cu–Sn alloy-coated steel–rubber interface

Cu–Sn coatings with varying Sn content were deposited on steel substrate by immersion route and the effect of variation of Sn content and the substrate roughness on the interfacial adhesion strength of Cu–Sn-coated steel substrates vulcanized with styrene butadiene rubber were investigated. The surface roughness of the coatings did not vary compared to pristine steel substrate with change in Sn weight% in the coatings. The coated surfaces exhibited bare spots or deep trough as micro-discontinuities in the coatings, where formation of Fe₂O₃ was evident from SEM-EDS, AES, and XPS analysis. Microstructural study of the coating cross-section and coating-substrate interface by transmission electron microscopy of cross-sectioned samples revealed inadequate penetration of coating inside these troughs. Peel test carried out on the Cu–Sn-coated steel–rubber joints showed mixed mode i.e. adhesive and cohesive mode of interfacial fracture irrespective of the coating composition. The peel test further indicated higher interfacial adhesion strength for Cu–Sn-coated samples than pure Cu-coated samples, with an optimum adhesion strength for the coatings containing 3–4?wt.% Sn.     

Polyurethane paint adhesion improvement on aluminium alloy treated by plasma jet and dielectric barrier discharge

The effect of atmospheric pressure plasma treatment on the adhesion between a protective coating and AA1100 alloy was investigated. Two plasma sources were used for surface modifications: atmospheric pressure plasma jet and dielectric barrier discharge. The surface roughness and water contact angle measurements were conducted in order to evaluate the changes on the aluminium surface after plasma processing. The paint coating was tested using the adhesion tape test (ASTM D3359). A significant improvement of surface wettability and adhesion was obtained after plasma treatments.     

Effects of the pretreatment of a cemented carbide surface on its properties and on the properties of diamond coatings deposited by oxygen–acetylene flame CVD

The influence of the pretreatment of the WC (6% Co) surface on its properties (i.e. roughness, grain size and chemical composition) and on the properties of flame-deposited coatings have been studied. The surface treatments included the action of an oxidizing oxygen/acetylene flame at 1000 °C, scratching with diamond particles (14–20 μm), mixture with iron (<45 μm) in an ultrasound bath, and seeding with a nm-sized diamond suspension. An acid treatment was included in the pretreatment sequence. It is found that the oxidizing flame and the seeding decrease the surface roughness of the substrate as well as the diamond coatings, at the same time increasing the adhesion of the coating. Ultrasound scratching with the diamond/iron suspension increases the roughness of both the substrate and the diamond coating and decreases the adhesion of the coating. Scratching with diamond particles shows a similar but lesser effect. Except for scratching with diamond, all the surface pretreatment procedures lead to an increase in the density of diamond particles: this increase is greatest for seeding. Our results indicate that good adhesion and a small surface roughness are best obtained by the use of an oxidizing flame followed by acid treatment and seeding with nanoparticles.     

石化防腐涂装工程表面预处理要求评述

石化设备与钢结构防腐涂装前须进行表面处理,表面处理对涂层使用寿命至关重要。探讨了涂层下金属腐蚀、涂层附着力、表面预处理与各类底漆相互关系。认为采用锈面底漆与多功能环氧涂料是较好办法。     

Adhesion of SiO2 thin films to plasma-treated SUS304 stainless steel substrates

The adhesion strength of the coated SiO₂ thin film to SUS304 stainless steel substrates with various surface treatment conditions is studied in this research. The surface of the SUS304 stainless steel substrate is first treated with 1000-W plasma and then a SiO₂ thin film is deposited onto the surface via radio-frequency magnetron sputtering. Scanning electron microscopy is employed to observe the surface and cross section of the coating and X-ray diffraction is used to analyze the crystallographic structure. Moreover, a nanoscratch test instrument was employed to examine the indentation, scratches, coating hardness, modulus of elasticity, coefficient of friction, and critical adhesion of the SiO₂ film and to obtain surface profiles. A comparison of the coating adhesion of the substrate surfaces with and without plasma treatment indicates that critical adhesion increases significantly after Ar/N₂/O₂ plasma treatment.