共查询到18条相似文献,搜索用时 62 毫秒
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利用扫描电子显微镜(SEM)和能谱(EDS)测试了电镀Ni-Sn-P合金镀层在人工海水中腐蚀前后表面形貌和合金成分的变化,结合X射线光电子能谱(XPS)对腐蚀后合金表面的组成进行了分析,并在此基础上探讨了Ni-Sn-P合金镀层在人工海水中的腐蚀机理。研究结果表明:电镀Ni-Sn-P合金在人工海水中耐蚀性优于Ni-P合金,由于人工海水中的氯离子的穿透效应而出现的局部腐蚀孔数较Ni-P合金大幅减少,腐蚀后Ni-Sn-P合金表面形成由SnO2、SnCl4、Ni3(PO4)2、NiO和Ni(OH)2组成的膜层,对合金耐蚀性的提高起到重要作用。 相似文献
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制备了一种Al-Sn-Ga-Bi-Pb-Cd新型铝合金阳极,研究铝阳极在常温及低温海水中的电化学性能和腐蚀形貌。结果表明:低温海水环境使铝阳极开路电位正移,20℃时开路电位约在-1.23 V(vs.SCE),4℃海水中开路电位偏移至-0.91 V。低温海水环境使电荷转移电阻(Rt)增大,减弱了合金的活化能力,20℃下Rt为1.56 m~2,4℃时增大到3.39 m~2。恒电流放电实验显示,20℃海水中阳极激活时间为5 min,稳定电位达到-1.31 V,而4℃时激活时间为30 min,稳定电位为-1.15 V。铝阳极溶解为局部腐蚀,电流密度在3 A/dm~2使铝阳极溶解更为均匀,溶解过程有部分金属发生脱落,腐蚀产物主要为氢氧化铝以及少量镁钙的氢氧化物。 相似文献
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通常,所有的腐蚀都是从焊缝处开始发生的。这是由于焊接区域的金属相当于一个铸体结构,抗腐蚀能力不如变形体的母材好,尤其是在局部腐蚀较强的地方,这种差距就更为明显了。而且在有些时候,设计需要焊接两种不同的金属材料。Hastellovy C-22(UNS N06022)本身具有极好的抗腐蚀能力和加工性能。而它的焊材也具有同样优异的抗腐蚀性能和好的强度及较高的延伸率。同时它也非常适用于异型材的过合金焊接。 相似文献
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A. S. Ismail 《SILICON》2016,8(2):211-216
The present paper discussed the corrosion behavior of aluminum-silicon-copper-manganese alloy compared with the pure aluminum metal which already reported. Weight loss tests carried out in concentration ratios of H 2 SO 4 solutions at different temperatures. As a part of the study, corrosion penetration rate determined within interval immersion periods of 5 h. At room temperature, it is observed that aluminum alloys shows decreasing of weight loss and more corrosion resistance in concentrations 10 and 15 % of H 2 SO 4 solutions compared with the obtained results of pure Al metal. Moreover, corrosion rate increases slightly with increasing concentration of H 2 SO 4media and the attack is more significant at 50 °C. Also, the corrosion penetration rate of Al alloy decreased in the same trend as a result of the formation of thin protective multi oxide films of aluminum, silicon, copper and manganese. Furthermore, the microscopic analysis showed that there is fine pits appeared on the Al alloy surface correlated directly with the increased exposure period in the acidic solution whereas in case of pure Al metal there were a many horizontal streaks formed along the surface. 相似文献
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采用静态失重法、极化曲线法、交流阻抗法等研究了2024铝合金,铝LY12,铸铝ZL101和铝镁合金在市售两种常见汽车防冻液中的腐蚀行为.研究表明,几种铝合金材料在两种汽车防冻液中的初期腐蚀速率相差较大,腐蚀速率随时间的增加呈现减小趋势.失重法、极化曲线以及交流阻抗的测试结果表明几种铝合金材料在2号汽车防冻液中的腐蚀较轻... 相似文献
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7005铝合金在模拟海水介质中的腐蚀行为研究 总被引:1,自引:0,他引:1
以7005铝合金作为研究对象,借助电化学测量和重量法研究7005和5052铝合金在模拟海水介质中的耐腐蚀性,分析介质浓度、温度及浸泡时间等对其腐蚀行为的影响规律,为7系铝合金耐蚀性的判断提供实验依据。结果表明:7005与5052均产生明显的钝化特征,钝化电流随NaCl浓度的升高而增大。随温度升高,两种铝合金的腐蚀速率均加快,但增幅不同。两种铝合金表面均以点蚀为主要特征,腐蚀72h后,7005表面发生较为严重的局部腐蚀,其腐蚀程度高于5052。 相似文献
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The corrosion behavior of (SnO2)x(Bi1.6 Pb0.4)Sr2Ca2Cu3O10-δ, (SnO2)x(Bi,Pb)-2223, in 0.5?M NaCl solutions at 30°C was studied using potentiodynamic polarization curves measurements, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) techniques as well as scanning electron microscopy (SEM) and energy dispersive X-ray emission spectroscopy (EDX). The polarization data indicated that SnO2 nanoparticles behave as a cathodic type inhibitor for the corrosion of (Bi–Pb)-2223 phase superconductors in simulating seawater solutions. The corrosion current density of (SnO2)x(Bi,Pb)-2223 in a NaCl solution decreases with the time elapsed from sample preparation. The CV of (SnO2)x(Bi–Pb)-2223 phase superconductors showed features similar to those of ideal capacitive behavior. The results indicated that a pure (Bi,Pb)-2223 phase superconductor is the most suitable choice for electrochemical capacitor applications in simulating seawater solutions. However, EIS measurements at different potentials revealed that the corrosion process is controlled not only by charge transfer but also by the diffusion process. These measurements also confirm that the corrosion rate of a cathodically polarized phase superconductor is less than that of an anodically polarized phase superconductor. SEM images and EDX analysis showed that the reduction of SnO2 nanoparticles to Sn decreases the corrosion rates of the superconducting materials. 相似文献