N,N′-二(4-羟基苄叉)乙二胺双希夫碱在HCl溶液中对5052铝合金的缓蚀作用

以合成的N,N′-二(4-羟基苄叉)乙二胺双希夫碱作为缓蚀剂,通过失重法、动电位极化曲线、电化学阻抗谱评定了该缓蚀剂在HCl溶液中对5052铝合金的缓蚀作用。结果表明:该缓蚀剂在1.0mol/L HCl溶液中对5052铝合金具有很好的缓蚀效果,且缓蚀率随着缓蚀剂含量的增加而增大;N,N′-二(4-羟基苄叉)乙二胺双希夫碱缓蚀剂在5052铝合金表面的吸附属于物理和化学的混合吸附,并遵循Langmuir吸附等温式。     

碳酸钠对搅拌摩擦加工AZ31镁合金缓蚀性能的影响

通过搅拌摩擦加工(FSP)手段,对3 mm厚的AZ31镁合金板材作表面加工处理.然后在质量分数为5%的NaCl腐蚀溶液中添加不同浓度的碳酸钠作为缓蚀剂,通过动电位极化曲线以及交流阻抗(EIS)测试,研究了室温下该缓蚀剂对镁合金母材及搅拌摩擦加工处理镁合金电化学行为的影响.结果表明,添加缓蚀剂后,FSP镁合金及母材的腐蚀电流密度均减小,极化电阻及电荷转移电阻均增大,而且FSP镁合金的缓蚀效率要优于母材的缓蚀效率,且随浓度的增加而增加,碳酸钠是一种有效的无机缓蚀剂,并且其缓蚀作用效果与金属表面状态密切相关.     

酸性介质中N,N′-双(2-亚甲基吡啶)-1,2-亚氨基乙烷对AZ91D镁合金的腐蚀抑制作用(英文)

采用电化学方法研究N,N′-双(2-亚甲基吡啶)-1,2-亚氨基乙烷(BPIE)Schiff碱在0.010 mol/L HCl溶液中对AZ91D镁合金的腐蚀抑制作用。动电位极化曲线表明,BPIE Schiff碱是一种混合型缓蚀剂。电化学阻抗谱(EIS)测量证实了BPIE的腐蚀抑制作用。随着缓蚀剂浓度的增加,由于有更多的缓蚀剂吸附在AZ91D镁合金表面,电荷转移阻力减小,双电层电容减小。电化学噪声(EN)分析获得的数据在时间和频率域与EIS和极化曲线所得结果表现出良好的一致性。采用扫描电子显微镜(SEM)、X射线衍射(XRD)和能量色散X射线(EDX),研究BPIE的缓蚀作用。SEM照片显示,在存在BPIE的情况下,AZ91D合金表面的腐蚀损伤得到减轻。XRD分析显示,在存在BPIE的情况下,对应于富镁α相的谱峰强度增大,表明合金样品的腐蚀程度低。EDX分析也证实了BPIE的缓蚀作用。此Schiff碱化合物通过物理吸附在合金表面,吸附行为遵循Langmuir等温吸附模型。     

Shot Noise Analysis to Investigate the Corrosion Inhibition of AZ91D Magnesium Alloy in Sulfuric Acid Solution

The corrosion inhibition of AZ91D magnesium alloy in 0.01 M H₂SO₄ by a Schiff base compound was investigated using Potentiodynamic polarization, Electrochemical Impedance Spectroscopy and Electrochemical Noise methods. It is found that the Schiff base acts as mixed-type inhibitor and the inhibition efficiency increases with concentration. Electrochemical impedance spectroscopy results showed that the Schiff base acts by adsorption at the metal/solution interface. Shot noise analysis showed that the inhibitor addition decreases the number of charge transfer events instead of the value of charge transfer at each electrochemical corrosion event. The corrosion inhibition effect was approved by suitable surface analysis.     

木质素磺酸钠对3.5%NaCl溶液中AZ31镁合金的缓蚀作用

采用失重法,极化曲线,电化学阻抗谱和扫描电子显微镜研究木质素磺酸钠(SLS)在质量分数为3.5%NaCl溶液中对AZ31镁合金的缓蚀作用。结果表明:在298 K时SLS可有效抑制AZ31在Na Cl介质中的腐蚀。当SLS为4.0 g·L~(-1)时,缓蚀率可达到最大。提高浓度后,其缓蚀率会下降。SLS是阴极型缓蚀剂,并且SLS在AZ31表面的吸附符合Langmuir吸附模型。由吸附自由能?G~0及Arrhenius活化能E_a可知,SLS在AZ31镁合金表面是化学吸附。     

MoO42-与 Zn2+对镁合金在 NaCl 溶液中的协同缓蚀作用

采用动电位极化曲线法,结合腐蚀后的表面微观形貌及EDS能谱分析,研究了MoO42-与Zn2+对AZ31镁合金在3.5%NaCl溶液中的协同缓蚀性能。结果表明:0.005 mol/L Zn2+与0.05 mol/L钼酸钠联合作用,可有效抑制镁合金在NaCl溶液中的腐蚀,Zn2+促进MoO42-在合金表面的吸附,缓蚀效果优于单一的钼酸盐缓蚀剂。缓蚀机制是:钼酸盐与Zn2+协同作用,使镁合金表面形成更为致密的钝化膜,从而抑制镁合金的腐蚀。     

磷酸钠在NaCl溶液中对AZ31镁合金的缓蚀作用

采用电化学阻抗法、动电位极化曲线法、全浸泡失重法和扫描电镜,研究了在3.5%(质量分数)Na Cl溶液中磷酸钠(Na3PO4)对AZ31镁合金腐蚀的抑制作用。结果表明:Na3PO4对3.5%Na Cl溶液中的AZ31镁合金具有缓蚀作用,其缓蚀率随着Na3PO4含量增大逐渐提高,当Na3PO4质量浓度为1.0 g/L时,缓蚀率达到81.5%。结合扫描电镜分析表明,Na3PO4在镁合金表面形成含有Mg(OH)2和Mg3(PO4)2的保护层,这层致密的膜减少了基体与Cl-接触,抑制了镁合金的阳极反应。     

Comparison of corrosion behaviors of AZ31, AZ91, AM60 and ZK60 magnesium alloys

The corrosion behaviours of four kinds of rolled magnesium alloys of AZ31, AZ91, AM60 and ZK60 were studied in 1 mol/L sodium chloride solution. The results of EIS and potentiodynamic polarization show that the corrosion resistance of the four materials is ranked as ZK60＞AM60＞AZ31＞AZ91. The corrosion processes of the four magnesium alloys were also analyzed by SEM and energy dispersive spectroscopy(EDS). The results show that the corrosion patterns of the four alloys are localized corrosion and the galvanic couples formed by the second phase particles and the matrix are the main source of the localized corrosion of magnesium alloys. The corrosion resistance of the different magnesium alloys has direct relationship with the concentration of alloying elements and microstructure of magnesium alloys. The ratio of the β phase in AZ91 is higher than that in AZ31 and the β phase can form micro-galvanic cell with the alloy matrix, as a result, the corrosion resistance of AZ31 will be higher than AZ91. The manganese element in AM60 magnesium alloy can form the second phase particle of AlMnFe, which can reduce the Fe content in magnesium alloy matrix, purifying the microstructure of alloy, as a result, the corrosion resistance of AM60 is improved. However, due to the more noble galvanic couples of AlMnFe and matrix, the microscopic corrosion morphology of AM60 is more localized. The zirconium element in ZK60 magnesium alloy can refine grain, form stable compounds with Fe and Si, and purify the composition of alloy, which results in the good corrosion resistance of ZK60 magnesium alloy.     

Investigation of the inhibition effect of 5-((E)-4-phenylbuta-1,3-dienylideneamino)-1,3,4-thiadiazole-2-thiol Schiff base on mild steel corrosion in hydrochloric acid

The inhibition effect of 5-((E)-4-phenylbuta-1,3-dienylideneamino)-1,3,4-thiadiazole-2-thiol (PDTT) Schiff base on mild steel corrosion in 0.5 M HCl was studied for both short and long immersion time. For this purpose, potentiodynamic polarization, electrochemical impedance spectroscopy, linear polarization resistance, hydrogen gas evolution, the change of open circuit potential as a function of immersion time, SEM and AFM techniques were utilized. The PDTT Schiff base has shown remarkable inhibition on the corrosion of mild steel in 0.5 M HCl solution. The high inhibition efficiency was attributed to the blocking of active sites by adsorption of inhibitor molecules on the steel surface.     

Improvement of corrosion resistance of AZ31 Mg alloy by anodizing with co-precipitation of cerium oxide

Anodizing of AZ31 Mg alloy in NaOH solution by co-precipitation of cerium oxide was investigated. The chemical composition and phase structure of the coating film were determined via optical microscopy, SEM and XRD. The corrosion properties of the anodic film were characterized by using potentiodynamic polarization curves in 17 mmol/L NaCl and 0.1 mol/L Na₂SO₄ solution at 298 K. The corrosion resistance of AZ31 magnesium alloy is significantly improved by adding cerium oxide to alkaline solution. In addition, the surface properties are enhanced and the film contains no crack.     

Fe41Co7Cr15Mo14C15B6Y2块体非晶合金在HCl溶液中的腐蚀行为

采用电化学极化曲线和电化学阻抗(EIS)测试方法研究Fe_(41)Co_7Cr_(15)Mo_(14)C_(15)B_6Y_2块体非晶合金在0.5,1,2以及4 mol/L HCl溶液中的腐蚀行为,并比较了1 mol/L HCl溶液中非晶合金和不锈钢的腐蚀行为.极化曲线测试结果表明,Fe_(41)Co_7Cr_(15)Mo_(14)C_(15)B_6Y_2块体非晶合金在各种浓度的HCl溶液中都具有很好的耐蚀性,阳极极化曲线表现出明显的钝化特征.随着HCl溶液浓度的增大,其耐蚀性能逐渐下降.在1 mol/L HCl溶液中,非晶合金的自腐蚀电位高于不锈钢,自腐蚀电流密度比不锈钢小1个数量级.EIS结果显示,在开路电位下,Fe_(41)Co_7Cr_(15)Mo_(14)C_(15)B_6Y_2非晶合金和不锈钢的Nyquist图均由单一的容抗弧构成,但非晶合金的电化学转移电阻Rt比不锈钢的大2个数量级,这一结果与极化曲线结果一致,说明非晶合金在HCl溶液中的耐蚀性能优于不锈钢.     

Effects of benzotriazole on anodized film formed on AZ31B magnesium alloy in environmental-friendly electrolyte

An environmental-friendly electrolyte of silicate and borate, which contained an addition agent of 1H-benzotriazole (BTA) with low toxicity (LD50 of 965 mg/kg), was used to prepare an anodized film on AZ31B magnesium alloy under the constant current density of 1.5 A/dm² at room temperature. Effects of BTA on the properties of the anodized film were studied by scanning electron microscopy (SEM), energy dispersion spectrometry (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), loss weight measurement, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS), respectively. The results demonstrated that anodized growth process, surface morphology, thickness, phase structure and corrosion resistance of the anodized film were strongly dependant on the BTA concentration, which might be attributed to the formation of an BTA adsorption layer on magnesium substrate surface. When the BTA concentration was 5 g/L in the electrolyte, a compact and thick anodized film could provide excellent corrosion resistance for AZ31B magnesium alloy.     

NH4F浓度对镁合金表面微弧氧化制备氟化物膜层结构和性能的影响

目的 考察乙二醇-氟化铵电解液中氟化铵浓度对镁合金表面微弧氧化制备氟化物膜层结构和性能的影响,提高镁合金氟化物膜层的耐腐蚀性能。方法 在含不同浓度NH4F的EG-NH4F电解液中,采用微弧氧化的方法制备氟化物膜层,NH4F质量浓度分别为40、60、80、100、120 g/L。通过扫描电子显微镜(SEM)、X射线能量色散谱仪(EDS)和X射线衍射仪(XRD),对膜层表面微观形貌和成分组成进行分析,并通过电化学测试表征了膜层的腐蚀防护性能,通过盐雾试验评估了膜层长效防腐蚀行为,通过SEM和EDS表征了腐蚀形貌和腐蚀产物。结果 在EG-NH4F中制备膜层的物相组成主要是MgF2。随着NH4F浓度的提高,微弧氧化的起弧电压与工作电压均逐渐减小,膜层中氟含量逐渐增加,膜层的孔径减小,孔数量分布更加均匀,膜层表面粗糙度降低。质量浓度为100 g/L NH4F的膜层自腐蚀电流密度(Jcorr)为2.226×10^‒7 A/cm²,较镁合金基材降低了1个数量级,极化电阻Rp增大到90.156 kΩ.cm²,其阻抗模量|Z|f=0.01 Hz=8.55×10⁵ Ω.cm²,与镁合金基材的阻抗模量|Z|f=0.01 Hz=8.86×10² Ω.cm²相比,提高了3个数量级。结论 微弧氧化处理能够显著改善AZ31镁合金的腐蚀防护性能。NH4F浓度的增加有利于提高膜层的耐腐蚀性能,质量浓度为100 g/L NH4F的膜层耐腐蚀性能最优。     

Environmentally friendly anodization on AZ31 magnesium alloy

A novel anodization which is environmentally friendly,low voltage and low energy consumption was developed to improve corrosion resistance of AZ31 magnesium alloy.The corrosion resistance of the anodic films was studied by electrochemical impcdance spectroscopy(EIS) and potentiodynamic polarization techniques.The microstructure and compositions of films were examined by SEM,XPS and XRD.A new kind of organic additive used in the electrolyte is friendly to the environment.The compact, intact and uniform co...     

氯化铈对镁合金在NaCl溶液中的缓蚀作用

采用电化学阻抗法和动电位极化曲线法研究了氯化铈对镁合金AZ31在3.5％NaCl溶液中腐蚀行为的影响,用扫描电镜(SEM)和能谱仪(EDS)分析了腐蚀产物膜的形貌和成分.结果表明,当NaCl溶液中加入50～200mg/L氯化铈时,镁合金的腐蚀速率均有降低,当稀土含量为l00mg/L时,腐蚀速率最低;加入适当的稀土,腐蚀...     

新型噁二唑类缓蚀剂的合成及其缓蚀性能

合成了一种恶二唑类缓蚀剂2,5-（2-十一烷基）-1,3,4恶二唑（简称HOX）,对其进行了表征,并采用静态失重法、动电位极化和电化学阻抗谱（EIS）研究其在HCl介质中对Q235钢的缓蚀作用。研究表明,所合成的恶二唑类化合物是一种性能优异的混合控制型酸性碳钢缓蚀剂,其在碳钢表面的吸附符合Langmuir吸附模型。     

十六烷基二甲基乙基溴化铵与 NH4 SCN 缓蚀协同效应

目的研究十六烷基二甲基乙基溴化铵(CDAB)与NH4SCN在硫酸介质中对Q235钢的缓蚀协同效应,并探讨其缓蚀机理和性能,以期为工业实际生产提供理论数据。方法运用失重法研究CDAB质量浓度与缓蚀率的关系,通过失重法、动电位极化曲线法和交流阻抗法分析CDAB与NH4SCN复配后的缓蚀率和缓蚀机理。结果仅添加CDAB时,缓蚀率随着CDAB质量浓度增大而增大,但缓蚀性能并不显著,当质量浓度为10 mg/L时缓蚀率仅为85.07%;当CDAB与30 mg/L的NH4SCN复配后,缓蚀率显著提高到96.73%,能有效抑制Q235钢在0.5 mol/L硫酸介质中的腐蚀。极化试验结果显示,该复配缓蚀剂是一种以控制阳极反应为主的混合型缓蚀剂,缓蚀率随CDAB质量浓度增大而增大,与交流阻抗法、失重法试验结果相一致。复配缓蚀剂在Q235钢表面的吸附服从Langmiur吸附等温模型,吸附吉布斯自由能ΔG0=-48.33 k J/mol,为自发吸附。结论 CDAB与NH4SCN在0.5 mol/L硫酸介质中具有优异缓蚀协同效应,能有效抑制腐蚀介质对Q235钢在的腐蚀,复配缓蚀剂具有较高的缓蚀率。     

十六烷基三甲基溴化铵对镁合金腐蚀行为的影响

采用动电位极化和电化学阻抗等方法检测了十六烷基三甲基溴化铵(CTAB) 对AZ31镁合金在3.5% NaCl溶液中腐蚀行为影响的规律, 用扫描电镜观察表面腐蚀产物膜的形貌并分析其组成. 结果表明, 当NaCl溶液中加入2000~3500 mg/L CTAB时, 镁合金的腐蚀速率降低, 且CTAB浓度为3500 mg/L时, 镁合金的腐蚀速率最低. 这主要是因为CTAB在镁合金表面发生吸附, 使阳极溶解过程受阻, 同时, CTAB减少了腐蚀产物膜内的微观缺陷数量, 减少了腐蚀介质的渗入通道, 增大了电荷转移阻力, 从而使镁合金的耐蚀性得到改善.。     

AZ31镁合金搅拌摩擦焊焊缝电化学性能的分析

试验的样品为3 mm厚挤压态AZ31镁合金,采用搅拌摩擦焊接工艺对焊而成.通过静态失重法、动电位极化曲线以及交流阻抗谱(electrochemical impedance spectroscopy,EIS)测试,研究了室温下浓度5%(质量分数)NaCl溶液中AZ31镁合金搅拌摩擦焊焊缝和母材的电化学行为.结果表明,在室温腐蚀介质中通过静态失重法测得AZ31镁合金母材和焊缝在168 h后的平均腐蚀速率分别为0.154和0.135 g/(m2·h),通过动电位极化曲线及交流阻抗谱(EIS)测得AZ31镁合金母材和焊缝的腐蚀电流分别为0.001 63和0.000 45 A/cm2,极化电阻分别为9.553和12.61Ω/cm2.AZ31镁合金搅拌摩擦焊焊缝的抗腐蚀性能优于其母材的表现.     

4-苯基氨基硫脲在盐酸介质中对Q235钢的缓蚀性能

目的研究4-苯基氨基硫脲(4-PTC)对Q235钢在1mol/L HCl中的缓蚀作用。方法采用异硫氰酸苯酯和水合肼为原料,合成4-PTC。采用熔点分析、核磁共振氢谱和红外光谱等方法确定合成物质为目标产物4-苯基氨基硫脲。采用静态失重法、电化学极化曲线法、电化学阻抗谱法和扫描电子显微镜法,分析研究4-PTC的缓蚀性能。结果静态失重实验表明,当4-PTC浓度增加到1.0 mmol/L时,缓蚀效率达到85.9%,在Q235钢表面吸附符合Langmuir吸附等温式,形成单分子吸附层。计算得到吉布斯自由能为?35.60 k J/mol,说明缓蚀剂分子在Q235钢表面吸附同时存在物理吸附和化学吸附过程。动电位极化曲线表明,该缓蚀剂是以阴极型为主的混合型缓蚀剂,当4-PTC浓度增加到1.0 mmol/L时,缓蚀效率达到83.6%。电化学阻抗谱表明,随4-PTC浓度的增加,电荷转移电阻值增大,双电层电容值减小,金属腐蚀速率降低,缓蚀作用增强。当4-PTC浓度增加到1.0 mmol/L时,缓蚀效率达到84.7%。扫描电子显微镜表明,缓蚀剂分子能有效保护金属表面,抑制腐蚀。结论在盐酸介质中,4-PTC对Q235钢具有优良的缓蚀性能。