电沉积Ni-W合金在NaCl溶液中的腐蚀行为

通过电沉积的方法制备了Ni-W晶态合金与Ni-W非晶态合金.采用极化曲线与电化学阻抗谱测试了Ni-W合金在0.5mol/L NaCl溶液中的腐蚀行为.结果表明,Ni-W非晶态合金在0.5mol/L NaCl溶液中的极化曲线与Ni-W晶态合金相比,腐蚀电位较正,且钝化区间明显.Ni-W非晶态合金在0.5mol/L NaCl溶液中的电化学阻抗谱容抗弧半径远远大于Ni-W晶态合金,并且随着浸泡时间的延长Ni-W非晶态合金的表面生成一层钝化膜,容抗弧半径变化较小,而Ni-W晶态合金的容抗弧半径随浸泡时间的延长而越来越小,表面腐蚀越来越严重.总体来说,Ni-W非晶态合金的耐蚀性能要远远优于Ni-W晶态合金.     

聚环氧琥珀酸对白铜在3％NaCl溶液中的缓蚀作用

目前,有关绿色缓蚀剂聚环氧琥珀酸（PESA）对铜及铜合金的缓蚀影响研究较少。运用交流阻抗法和极化曲线法考察了PESA及其与Na2SiO3复配后对白铜B10在3％NaCl溶液中的缓蚀作用。结果表明,PESA是一种阳极型缓蚀剂,具有一定的缓蚀作用,浓度为15mg／L时,缓蚀率最大,为50．35％;PESA和5～20mg／L...     

Laurus nobilis L. oil as green corrosion inhibitor for aluminium and AA5754 aluminium alloy in 3% NaCl solution

The influence of (30%, v/v) ethanolic solution of Laurus nobilis L. oil on the corrosion inhibition of aluminium and AA5754 aluminium alloy in 3% NaCl solution was studied by weight loss method, potentiodynamic polarization, and linear polarization method. The polarization measurements show that addition of this oil in concentrations ranging from 10 ppm to 50 ppm induces a decrease of cathodic currents densities. The results confirm that AA5754 alloy has better corrosion resistance in 3% NaCl solution than pure aluminium, while the oil investigated has better inhibition action on corrosion process of pure aluminium. The surface analysis via SEM techniques indicate that the active molecules from L. nobilis L. oil absolutely retard the pitting corrosion on the specimen surfaces.     

含Ce的CuCrZr合金退火前后在氯化钠溶液中的电化学性能

退火作为工业上控制和改变金属材料组织、结构和性能的重要手段,在生产中具有很重要的意义.采用电化学工作站研究了含稀土Ce的CuCrZr合金退火前后在氯化钠溶液中的电化学性能.结果表明,稀土元素Ce的添加有利于提高合金的耐蚀性.对于未退火的研究试样,Ce的添加降低了合金的腐蚀电流;而对于经过退火处理的试样,退火增加了合金在氯化钠溶液中的腐蚀电流,但Ce对耐蚀性的提高作用依旧存在,它的存在可减缓退火对合金耐蚀性的降低作用.同时,试样在1 mol/L NaCl水溶液中的阻抗谱表明:退火提高了试样表面产物膜的致密度,增加了腐蚀反应的难度.     

三乙醇胺对镁合金的缓蚀效果及其吸附行为研究

为了研究三乙醇胺在氯化钠溶液中对镁合金的缓蚀效果,运用电化学工作站和扫描电子显微镜测试分析了镁合金在含三乙醇胺的氯化钠溶液中的微分电容曲线、表面覆盖度、循环极化曲线、电化学阻抗谱和表面微观形貌。结果表明:在氯化钠溶液中添加3 m L/L三乙醇胺时,镁合金与溶液界面的微分电容值减小,微分电容曲线出现电位平台,零电荷电位正移;随着阳极极化加强,三乙醇胺在镁合金表面覆盖度下降,产生阳极脱附现象;随着浸泡时间延长,镁合金表面出现裂缝,并逐渐发展为腐蚀孔,腐蚀产物分布在蚀孔周边,且易脱落。     

新型不对称双季铵盐表面活性剂的制备及缓蚀性能

本文以十二烷基二甲基叔胺、十六烷基二甲基叔胺、氯乙酰氯和1,3-丙二胺为原料,通过三步法制得一种新型高效、环境友好的不对称双季铵盐表面活性剂,研究了其在1 mol/L盐酸溶液中对2024 Al-Cu-Mg合金表面的缓蚀性能和机理.通过红外光谱和核磁共振氢谱对其结构进行表征;通过表面张力获得其临界胶束浓度(CMC);利用...     

双稀土处理液对H62黄铜成膜耐蚀性能的影响

为了提高H62黄铜合金的表面性能,通过正交试验获得了最佳锅、钵双稀土处理液配方。利用硝酸点滴、中性盐雾试验评价了H62黄铜合金钝化膜的耐蚀性能,通过电子探针(EPMA)观测了其表面形态结构及元素分布,利用电化学方法表征了 H62黄铜表面钝化膜在3.5%NaCl溶液中的缓蚀行为,采用XRD对H62黄铜表面钝化膜的成分进行了检测。结果表明:H62黄铜合金由镉、钵双稀土处理液钝化成膜的主要成分为Cu2O,CeO2,La(OH)3,Ce(OH)4;致密的钝化膜耐硝酸点滴时间达到21.98s,在3.5%NaCl溶液自腐蚀电位增加,腐蚀电流降低,腐蚀速度明显降低,耐蚀性能增加,耐中性盐雾性能明显优于鋪单一稀土处理液。     

镁锂合金碱性条件下腐蚀的EIS分析

为了研究镁锂合金在碱性条件下的腐蚀行为,测试了镁锂合金在不同pH值0.4 mol/L NaCl溶液中的电化学阻抗谱、pH=9和pH=14条件下不同浓度的NaCl溶液中的电化学阻抗谱及在不同体系的碱性NaCl溶液中腐蚀100 h过程中的电化学阻抗谱,并对电化学阻抗谱进行了拟合、分析.结果表明:溶液的Cl-和pH值显著影响着腐蚀速率,当Cl-浓度相同时,溶液的pH值越大电化学反应电阻越小;当pH相同时Cl-浓度越高电化学反应电阻越小,并且随Cl-浓度的增加pH值对腐蚀速率的影响逐渐减弱;镁锂合金在低Cl-浓度高pH值的条件下腐蚀0~100 h的电化学阻抗谱中随腐蚀时间的增加,高频弧和低频弧均扩张,在低Cl-浓度低pH值及高Cl-浓度任意pH值条件下低频弧变化显著,先扩张后收缩,腐蚀100 h时镁锂合金在Cl-浓度较低的溶液中无论pH值如何,其腐蚀速率远远小于在Cl-浓度较高的溶液中的腐蚀速率.     

乙醇胺和KI对低硅高硫铁的缓蚀作用

缓蚀剂对古代铁器保护具有重要的作用.按不同比例配制了5种乙醇胺与KI的复合缓蚀剂,采用失重法、SEM显微形貌观察、电化学极化曲线和电化学交流阻抗谱研究了3.5%NaCl溶液中乙醇胺和KI对低硅高硫铁的缓蚀作用.结果表明:加入乙醇胺和KI复配缓蚀剂,能显著降低低硅高硫白口铁的腐蚀速率;复配缓蚀剂通过增大金属腐蚀的电化学反应电阻,抑制阴极的氧还原反应速度,起到了缓蚀作用.     

聚天冬氨酸和钨酸钠复配对氯化钠溶液中铜的缓蚀作用研究

采用交流阻抗法和极化曲线法,研究了两种环境友好型水处理药剂聚冬天氨酸和钨酸钠的单一配方以及复配对3%NaCl溶液中铜的缓蚀效果.研究表明:聚冬天氨酸和钨酸钠各自的单一配方对于铜均具有一定的缓蚀效果,其中聚冬天氨酸在浓度为40 mg/L时效果最佳,钨酸钠在浓度为350 mg/L时效果最佳.当二者复配使用时,在缓蚀剂总浓度为40 mg/L时,聚冬天氨酸与钨酸钠配比为1:5时效果最佳,具有协同效应;在缓蚀剂总浓度为350 mg/L时,聚冬天氨酸与钨酸钠配比为7:1,5:1,3:1,1:5,1:7时具有明显的缓蚀效果,且具有协同效应,其中以配比7:1为最佳.     

硫脲和I~-对碳钢在酸洗液中的协同缓蚀作用

目前,鲜见硫脲与I~-的复配技术及其在酸洗液中对碳钢缓蚀性能的报道。采用失重法、开路电位、电化学交流阻抗谱和动电位极化曲线,研究了硫脲和I~-在硫酸洗液中对碳钢的协同缓蚀效应,并采用扫描电镜对碳钢腐蚀前后的腐蚀形貌进行表征。结果发现,硫脲和I~-复配后可明显降低碳钢在硫酸洗液中的腐蚀速率,在含0.01mol/L硫脲的硫酸溶液中,添加0.01 mol/L的I~-可将对碳钢的缓蚀效率从88.7%提高到96.1%。     

类金属元素对化学沉积坡莫合金成分、结构及耐蚀性的影响

用化学沉积法在铜和碳钢基体上施镀Ｎi-Fe-P和Ｎi-Fe-P-B坡莫合金镀层,Ｘ射线衍射测定结果及镀层的腐蚀试验结果表明,镀液中还原剂的沈度,金属盐比及pH值,对镀层成分,晶体结构及耐蚀笥有直接影响,使镀层具有非晶态结构和较强的钝化趋势,是获得蚀性良好的镀层的主要条件,适当提高Ｆe含量,在镀液中加入Ｂ元素,有利于提高镀层的耐蚀性。     

[HMIM]BF_4对盐酸中A3和HP13Cr钢的缓蚀行为

为了减少钢铁冶金酸洗过程中酸液对不锈钢或碳钢的过腐蚀,得到高效的新型缓蚀剂材料,利用失重法、电化学法及扫描电子显微镜(SEM)等研究了不同浓度离子液体[HMIM]BF_4对HP13Cr不锈钢以及A3碳钢在1 mol/L盐酸溶液中的缓蚀特性和吸附行为。失重试验得出,试样在1 mol/L盐酸溶液中的腐蚀速率随离子液体添加浓度的增大而减小,即离子液体缓蚀效率随其浓度增加而增大;SEM结果显示,盐酸溶液中离子液体的添加对不锈钢HP13Cr以及碳钢A3均能起到显著的保护作用。电化学测试表明,该离子液体对这2种钢材的缓蚀作用均属于混合型抑制,但阳极抑制作用表现更强。离子液体对金属的防护作用与其在金属表面的吸附行为有关;[HMIM]BF_4在2种钢材表面的吸附行为符合Langmuir吸附等温线,兼具物理、化学吸附特性,热力学参量表明吸附过程为自发、吸热的熵增过程。相比于双咪唑季铵盐,[HMIM]BF_4离子液体缓蚀剂保护性能更优异,而且对于A3碳钢更为有效。     

Influence of coating on short steel fiber reinforcements on corrosion behavior of aluminium base short steel fiber reinforced composites

Steel fiber reinforced aluminium composites are attractive materials of high specific strength but exhibit poor resistance against electrochemical corrosion. The study discusses the electrochemical corrosion behavior of uncoated, copper and nickel coated short steel fiber reinforced aluminium and Al–2Mg matrix composites in 1 (N) NaCl solution. Galvanic corrosion between the steel fiber and aluminium governs the corrosion behavior of these composites. It has been observed that open circuit potential (OCP) is shifted to more negative side with copper coating on the fibers and to the more positive side on coating the fibers with nickel. Compared to the uncoated fiber higher corrosion current density indicates corrosion rate was observed for the copper coated fiber reinforced composites where as a lower current density was noted for the nickel coated fiber reinforced composites was observed. Addition of 2 wt% magnesium to aluminium alloy matrix increased the corrosion current density. The corrosion mechanism in these composites is dominated by galvanic cell formation that is evident from the dissolution of Al matrix near the peripheral region of steel fibers.     

Effects of High Magnetic Field on Solidification and Corrosion Behaviors of Magnesium Alloy

The solidification behaviors of AZ61 magnesium alloy under a high magnetic field were studied. The corrosion property of AZ61 alloy was investigated in a solution of 3.5 mol/L NaCI by measuring electrochemical p.olarization. The results show that the high magnetic field can refine microstructure and benefit aluminum transfer. The crystal of α-Mg is induced to orient with their c-axis parallel to the magnetic field. The corrosion studies indicate that different crystal plane of magnesium has different corrosion property. The passivating films on the α- and b-planes have higher corrosion resistance than that on the c-plane. Aligned structure affects the corrosion property of AZ61 magnesium alloy.     

Corrosion behavior of AZ91 magnesium alloy in dilute NaCl solutions

The corrosion behavior of AZ91 magnesium alloy in dilute NaCl solutions was studied using electrochemical measurements, whereby a corrosion map in terms of electrode potential and chloride concentration [Cl⁻] was obtained. AZ91 alloy exhibited the corrosion and passivation zones in dilute NaCl solutions. The passivation zone became narrow with increasing [Cl⁻]. The values of open-circuit potential were in the passivation zone when the [Cl⁻] was less than 0.5 mol/L. XRD patterns showed the presence of the Mg(OH)₂, Mg₅(CO₃)₄(OH)₂·8H₂O and MgO phases in the corrosion product, whereas the latter two phases found in the passive film.     

TiO2纳米管阵列膜的制备及对304不锈钢的光生阴极保护效应

应用电化学阳极氧化法在Ti表面构筑不同的TiO2纳米管阵列膜。采用XRD、SEM、XPS表征薄膜的结构、形貌和组成。通过电化学阻抗谱及电位随时间变化的测试,考察TiO2薄膜的光生阴极保护效应。结果表明薄膜主要由锐钛矿型的TiO2纳米管阵列组成,当304不锈钢耦连于紫外光照下的TiO2薄膜电极时,其界面反应电阻变小,电极电位显著降低,说明TiO2纳米管薄膜能够对不锈钢产生良好光生阴极保护效应,特别是掺Fe的TiO2薄膜在光照时可使不锈钢电位降低约450mV,而且在暗态时也能较长时间保持对不锈钢的阴极保护作用。     

溴化锂溶液中苯并三氮唑对碳钢缓蚀作用研究

为降低溴冷机中碳钢的腐蚀,通过失重法和电化学方法研究了含有0.07 mol/L LiOH和150mg/L Na2MoO4的55%LiBr、60%LiBr溶液中苯并三氮唑(BTA)对碳钢的缓蚀作用.结果表明,在溴化锂溶液中添加BTA时可显著降低碳钢腐蚀;55%LiBr、60%LiBr溶液中BTA的最佳添加量为100 mg/L;55%LiBr溶液中,BTA通过与铁离子形成Fe-BTA型配合物覆盖在金属表面阻碍浸蚀性Br-吸附而起缓蚀作用;60%LiBr溶液中,BTA则与MoO42-共同作用,在碳钢表面形成MoO2、MoO3和Fe-BTA致密钝化膜减缓金属活性溶解.     

Experimental and theoretical assessment of the inhibiting action of <Emphasis Type="Italic">Aspilia africana</Emphasis> extract on corrosion aluminium alloy AA3003 in hydrochloric acid

The adsorption of Aspilia africana extract and subsequent corrosion inhibition of aluminium alloy AA3003 in hydrochloric acid solutions have been investigated using gravimetric and electrochemical techniques. Inhibition efficiency increased with extract concentration and temperature rise. Polarization studies revealed that the extract essentially inhibited the cathodic reaction. An adsorption mechanism involving physisorption and chemisorption of extract constituents at low and high temperatures, respectively, has been proposed from the trend of adsorption-free energies. Quantum chemical computations and molecular dynamics simulations described the individual contributions of some extract constituents to the observed inhibiting effect.