Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《腐蚀科学与防护技术》
Abstract: γ- glycidoxypropyltrimethoxysilane (GPTMS) was doped into pigment- free waterborne epoxy to prepare silane-incorporated coatings on galvanized steel by electrophoresis. The corrosion performance of the prepared coatings was then studied by means of electrochemical impedance spectroscopy and scanning electrchemical microscopy. Results showed that the addition of organosilane significantly improves the corrosion performance of electrophoretic epoxy coatings in corrosive medium. Silane incorporation suppresses the water absorption and inhibits the swelling of epoxy coating. The corrosion protection mechanism was proposed. On one hand, the addition of GPTMS improves the cross-linking degree of the coating; and on the other hand, GPTMS-enriched layer which was preferentially formed at the metal/coating interface during the electrophoresis process results in better adhesion between the substrate and the coating.
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《腐蚀科学与防护技术》
Abstract: Al and Al-Mn alloy coatings were electrodeposited on 20# steel substrate with ionic liquids of AlCl3-EMIC (1-ethyl-3-methylimidazolium chloride) or AlCl3-MnCl2-EMIC. The composition, morphology, microstructure and corrosion behavior of the coatings were characterized by SEM with EDS, XRD analysis and polarization curves. The electrodeposited Al-Mn alloy coatings are dense, with good adhesion on 20# steel substrate. The results of electrochemical tests showed that the as- fabricated Al and Al-Mn alloy coatings have lower corrosion rates than the bare 20# steel substrate. Among the investigated coatings, the Al-Mn alloy coating with 20.26% Mn exhibited the lowest corrosion rate.
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-19 Cooperative journals: 《金属学报》
Abstract: Since electrochemical impedance spectroscopy, polarization curve and hydrogen collection were the main technologies for corrosion research of Mg and its alloy. However, those methods only provide the mean information of entire surface of corrosion electrode. In this work, H2 evolution and active sites of pure Mg from localized sites (point, line and surface) in NaCl and Na2SO4 solution based on generation/collection and feedback modes of scanning electrochemical microscopy (SECM) were studied. The results indicate that both cathodic and anodic polarization are in favor of H2 evolution in NaCl and Na2SO4 solution, which is well in line with the negative difference effect by the classical H2 collection, but the SECM results show that the H2 evolution in localized sites is not uniform and stable. The H2 evolution rate increases with NaCl concentration increasing, which is opposite in Na2SO4 solution. The higher NaCl concentration, anodic polarization and lower pH value accelerate the formation of active sites on pure Mg surface.
Subjects: Materials Science >> Materials Science (General) submitted time 2016-11-12 Cooperative journals: 《中国腐蚀与防护学报》
Abstract:本文综述了金属材料在流体冲刷条件下的腐蚀研究现状、不同环境因素和材料性质对冲刷腐蚀机理的影响规律。冲刷腐蚀主要由冲刷磨损和电化学腐蚀组成,它们对总腐蚀速率的贡献与各种环境因素有关,其中,流体流速及溶液中沙含量均存在着临界值,流速较低时电化学腐蚀占主导地位,超过临界值冲刷磨损占主要作用,其他条件不变时,溶液中泥沙含量超过临界值时,腐蚀机制由电化学腐蚀转变为冲刷磨损。同时,探讨了冲刷腐蚀研究的未来发展趋势。
Subjects: Materials Science >> Materials Science (General) submitted time 2016-11-08 Cooperative journals: 《腐蚀科学与防护技术》
Abstract:将γ-(2,3环氧丙氧)丙基三甲氧基硅烷(GPTMS)掺杂到不含颜料的水性环氧树脂中,通过一步电泳法在镀锌钢表面构建得到硅烷掺杂的电泳漆涂层。采用电化学阻抗谱和扫描电化学显微镜技术研究了涂层体系的防护性能,并结合其它手段开展了机理研究。结果表明有机硅烷的加入能够显著提高环氧电泳漆涂层在腐蚀介质中的防护性能,硅烷掺杂抑制环氧涂层的吸水和溶胀。文中提出了硅烷掺杂电泳漆涂层的如下防护机理:一方面,GPTMS的掺杂增加了涂层的交联程度;另一方面,电泳过程中促进GPTMS组分在金属与涂层界面的优先沉积形成富集层,从而提高了基体与涂层间的结合力。