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《Journal of Adhesion Science and Technology》2013,27(7):907-921
A variety of metallic and oxide coatings were deposited under various conditions on 1020 mild steel substrate by conventional plasma spraying. The coating thickness, microhardness, cohesion and adhesion failure loads, friction coefficient, and abrasive wear resistance were evaluated. The coatings were classified as follows, in order of decreasing microhardness and wear resistance: alumina, chromia, 316 stainless steel, Ni-5% Al, elemental aluminum and aluminum-polyester. Wear resistance increased with increasing microhardness and decreasing friction coefficient. The microhardness and wear resistance of high-velocity oxy-fuel (HVOF) diamond jet (DJ)-sprayed aluminum were found to be superior to those of plasma-sprayed aluminum. Plasma or flame-sprayed metallic coatings adhered well to the substrate. The cohesion, adhesion, microhardness, and wear resistance of alumina coatings exceeded those of equally thick chromia coatings. 相似文献
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稀土对化学镀镍溶液稳定性的影响 总被引:4,自引:0,他引:4
研究了4种稀土元素(La、Y、Eu和Nd)对化学镀镍镀液稳定性、沉积速度以及镀层耐磨性的影响,并初步探讨了稀土元素在镀液中的作用机理。结果表明:4种稀土元素对镀液均有影响,其中Y的效果最明显,La的影响程度较小。适量的稀土均能增加镀液的稳定性,提高镀层的沉积速度和耐磨性。稀土元素Y的添加量在0,04g/L时,所得镀层的综合性能最好。 相似文献
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采用赫尔槽试验、分散能力测定法、扫描电镜、X射线衍射、能谱分析、硬度测量及交流阻抗谱,研究指甲花萃取物(主要成分为2-羟基-1,4-萘醌)对镍从瓦特镀液中电沉积(以低碳钢为基体)的影响。在温度40~50°C和pH4.5~5.0的条件下,从含60mL/L指甲花萃取物的瓦特镀镍液中得到的镀层具有良好的耐蚀性和硬度。指甲花萃取物作为瓦特镀镍液的添加剂,极大地提高了镀液的分散能力和电流效率。在最佳指甲花萃取物浓度下所得的镀镍层为晶态,结晶细致。 相似文献
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Electroless nickel (EN) composite coatings incorporated with PTFE and/or SiC particles demonstrated significantly improved mechanical and tribological properties as well as low surface energy which are desired for anti-sticking and wear resistant applications. The corrosion resistance of these composite coatings, however, has not been systematically studied and compared. This work aimed to investigate the corrosion characteristics of EN composite coatings using electrochemical measurements which include open circuit potential (OCP), electrochemical impedance spectroscopy and potentiodynamic test. The effects of the co-deposited particles on corrosion behavior of the coatings in 1.0 N H2SO4 and 3% NaCl media were investigated. The surface autocatalytic properties and the post-heat-treatment on coating corrosion resistance were also discussed. The results showed that both EN and EN composite coatings demonstrated significant improvement of corrosion resistance in both acidic and salty atmosphere. Ni striking substantially enhanced the corrosion resistance due to the improvement of the surface autocatalytic properties and homogeneity. Proper post-heat-treatment significantly improves the coating density and structure, giving rise to enhanced corrosion resistance. 相似文献
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《国际智能与纳米材料杂志》2013,4(3):207-216
This article describes the influence of controlling in-flight hot particle characteristics on properties of plasma sprayed nanostructured yttria stabilized zirconia (YSZ) coatings. This article depicts dependence of adhesion strength of as-sprayed nanostructured YSZ coatings on particle temperature, velocity and size of the splat prior to impact on the metallic substrate. Particle temperature measurement is based on two-color pyrometry and particle velocities are measured from the length of the particle traces during known exposure times. The microstructure and adhesion strength of as-sprayed nano-YSZ coatings were studied. Field emission scanning electron microscopy results revealed that morphology of coating exhibits bimodal microstructure consisting of nano-zones reinforced in the matrix of fully melted particles. The coating adhesion strength is noticed to be greatly affected by the melting state of agglomerates. Maximum adhesion strength of 42.39 MPa has been experimentally found out by selecting optimum levels of particle temperature and velocity. The enhanced bond strength of nano-YSZ coating may be attributed to higher interfacial toughness due to cracks being interrupted by adherent nano-zones. 相似文献
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In this study, the geometry of the tyre cord adhesion test (TCAT) was used to evaluate the adhesion strength between rubber and fibre. The activation energy (ΔE) of rubber compound used in this study was 72.43 kJ mol?1 and the difference of cure state between the inside and outside regions of the TCAT specimen with curing time was elucidated using the value of ΔE. The difference in cure state between the inside and outside regions of the TCAT specimen corresponded to the effect of 5.06 min of curing time. The cure state of the inside region of the TCAT specimen greatly affected the final adhesion strength and the results were confirmed by additional experiments. It was concluded that optimum adhesion between rubber and cord could not be obtained in a TCAT specimen unless the additional curing time to reach the optimum cure state of the inside region of the TCAT specimen was taken into account. Copyright © 2004 Society of Chemical Industry 相似文献
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Effects of the functional groups of polystyrene on its adhesion improvement and corrosion resistance
《Journal of Adhesion Science and Technology》2013,27(9):947-955
Novel functionalized polystyrenes having groups such as epichlorohydrin, epoxy, acetyl, C=C double bond, and carboxyl were synthesized by the reaction of polystyrene with epichlorohydrin, unsaturated hydrocarbons, and organic anhydrides in the presence of Lewis acid catalysts. The adhesion capability and corrosion resistance of the new synthesized functionalized polystyrenes to metals under various conditions were investigated. A very good relationship was observed between the quantity of functional groups bonded to the aromatic rings of the polystyrenes and the adhesion and corrosion resistance properties of the polyfunctionalized polystyrenes. It was also observed that the new polyfunctionalized polystyrenes obtained by chemical modification with maleic anhydride, acetic anhydride, isoprene, butadiene, and epichlorohydrin in the presence of cationic catalysts resulted in high adhesion and anti-corrosion properties. 相似文献
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Investigation of the mechanical,thermal, and anticorrosion properties of epoxy nanocomposite coatings: Effect of synthetic hardener and nanoporous graphene
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Mehdi Naderi Morteza Hoseinabadi Mohammad Najafi Siamak Motahari Mohammad Shokri 《应用聚合物科学杂志》2018,135(17)
In the present study, epoxy samples containing nanoporous graphene (NPG) were synthesized and analyzed in terms of mechanical, morphological, thermal, adhesion, and anticorrosion properties. To this end, the employed curing agents (hardeners) were synthesized and NPG content was varied from 0 to 1 wt %. By using a hardener with aliphatic side chains, the toughness of the nanocomposite was improved without a decrease in the modulus. Adding 1 wt % NPG increased the modulus of the nanocomposite by about 30%. The dynamic mechanical results showed an increment in the glass transition of the samples containing 1 wt % NPG. Field emission scanning electron microscopy images were used to observe the fracture surface of the nanocomposites. The thermogravimetric analysis analysis also confirmed that using synthetic hardener and NPG as the nanofiller enhanced the thermal resistance of the samples. The images of the protected metal panel surfaces and their coatings were used to study adhesion and anticorrosion properties. These results indicated that the hardener synthesized in this work along with NPG improved the mechanical, thermal, adhesion, and anticorrosion properties of the epoxy nanocomposites effectively. The specific characteristic of the synthetic hardener was its chemical structure including both aliphatic and cyclic polyamines as the side groups. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46201. 相似文献
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Internal stress in organic coatings has been considered for a long time as the origin of cracking and checking. However, much more interesting and informative are changes of internal stress when coatings are exposed to water. It is demonstrated that these changes indicate interfacial relaxation processes at the coating/support interface, which are related to wet adhesion and to the recovery of adhesion after the evaporation of water and allow the measurement of the permeability of coatings on substrates to water. There is evidence that a special state of adhesion exists before delamination takes place, which may be characterized as ‘sliding or mobile bonding’. 相似文献
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Spontaneous polymerization (S‐Poly) is a novel process for forming protective polymer coatings on metals. The S‐Poly mechanism on copper is discussed for one typical monomer system. Poly(ethylene glycol) ethyl ether methacrylate (EEM), a flexible monomer, was first introduced into a styrene/N‐phenyl maleimide system that we had used for aluminum and steel. The effects of EEM on the composition, apparent molecular weight, thermal properties, and other properties of the coatings were studied with reflectance Fourier transform infrared, gel permeation chromatography, differential scanning calorimetry, and water‐uptake and adhesion experiments. N‐(4‐Fluorophenyl) maleimide (4FMI), a strongly hydrophobic monomer, was further incorporated into the EEM copolymer for improved water impermeability. The resultant coatings, which included EEM and 4FMI units, showed good bonding strength to copper and better ductility and protective properties than other coatings in both corrosion and pinhole tests. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1749–1757, 2002 相似文献