电解液的浓度和温度对铝空气电池负极性能的影响

通过测量极化曲线、电化学阻抗谱和恒流极化曲线,研究了氯离子浓度和溶液温度对铝空气电池负极腐蚀性能和放电性能的影响.结果表明:当氯化钠溶液浓度为3.5%时,铝合金腐蚀速率最快,随着氯化钠溶液浓度升高,铝合金恒流极化稳定电位负移,极化减小.溶液温度升高,加快了铝合金的腐蚀.当溶液温度为50℃时,由于铝合金表面有腐蚀产物层的生成,腐蚀速度略有降低.当溶液温度为40℃时,铝合金表现出最低的恒流极化稳定电位.     

不同热处理态2024铝合金的腐蚀行为

分别在3.5%NaCl溶液、3.5%NaCl＋1.0%H2O2溶液和pH=12的3.5%NaCl溶液中进行动电位极化实验,研究2024 Al-Cu-Mg合金在不同热处理状态下的腐蚀行为。极化曲线表明,随着合金时效时间的延长,合金的腐蚀电位向负方向移动;向NaCl溶液中添加H2O2会使腐蚀电位正移;在pH=12的3.5%NaCl溶液中的极化曲线表现出明显的钝化现象。腐蚀试样表面表现为常见的腐蚀特征,但也有扩大的点蚀、晶间腐蚀现象出现。循环动电位极化曲线显示有宽的循环极化滞后环,不同的腐蚀模式表明合金的点蚀生长对合金的热处理状态敏感。通过显微组织分析,探讨了不同热处理状态下合金在不同NaCl溶液中的腐蚀机理。     

新型低硅铸造铝合金耐腐蚀行为研究

采用浸泡腐蚀试验、电化学极化和交流阻抗谱测试等手段,并利用扫描电镜(SEM)和能谱(EDS)等分析方法,研究了汽车转向节用新型低硅铸造铝合金在3.5%NaCl腐蚀介质下的腐蚀行为和规律。结果表明,低硅铸造铝合金在3.5%NaCl腐蚀介质下,其耐蚀性能与传统A356铝合金相当,其腐蚀产物主要为Al(OH)_3、AlCl_3及Al_2O_3;另外,Si含量在3%至4%变化时,Si含量增加引起二次枝晶壁间距减小,耐蚀性能随Si含量增加而提高;同时Cr元素的加入,使得材料的局部腐蚀倾向降低,但腐蚀速率有所提高。     

高活性铝合金负极材料的电化学性能研究

研制一种用于碱性电池的高电化学活性的新型铝合金负极材料.用熔铸法和压力加工技术将铝合金制成薄板;用电化学方法测试了材料的电化学性能;用排水法测试了材料静态浸泡腐蚀的析氢速率;结果表明:新型铝合金负极在3.5%NaCl水溶液中、3.5%NaCl 25%NaOH水溶液中均具有很负的电极电位和低的自腐蚀速率;其组成的Al/AgO碱性单体电池:当放电电流密度为750mA/cm2时,单体电池电压为1.62V,析氢速率≤0.21ml/(cm2·min).研制的新型铝合金负极材料,可望开发高能量密度的铝合金电池.     

铝合金化学镀Ni-P合金层及其耐蚀性研究

为进一步提高2024铝合金的耐蚀性,采用化学镀技术在铝合金表面沉积了Ni-P合金层,用扫描电镜观察镀层的表面形貌,通过开路电位、动电位极化和交流阻抗等电化学测试方法对比了镀层和2024铝合金在3.5%NaCl溶液中的耐蚀性。结果表明:通过该工艺可以在铝合金表面沉积一层致密的Ni-P层,镀层的自腐蚀电位比基体更正,自腐蚀电流密度更低,铝合金的耐蚀性得到提高。     

7050铝合金应力腐蚀敏感性和钝化膜引起的膜致应力随电位变化的一致性

用流变应力差值法测量了不同极化电位下7050铝合金在3.5%NaCl 水溶液（pH=10）腐蚀过程中表面钝化膜形成的拉应力,并用慢应变速率拉伸法测量了不同极化电位下的应力腐蚀敏感性。结果表明:7050铝合金在溶液中自然腐蚀时,表面钝化膜会产生一定的拉应力;阳极极化使表层拉应力明显上升,且随着电位升高应力增大;阴极极化时,当电位E ≥-1100mV时表层拉应力随着电位的升高而降低,当电位≤E-1100mV时拉应力随着电位升高而升高。应力腐蚀敏感性随外加电位变化规律和钝化膜引起的附加拉应力变化完全一致。     

脉冲电沉积纳米晶Ni-Co合金镀层腐蚀特性研究

采用X射线衍射(XRD)、扫描电镜(SEM)、能谱分析(EDS)等方法研究了脉冲电沉积法制各纳米晶Ni和纳米晶Ni-Co合金镀层的组织结构、表面形貌和成分.用浸泡法和电化学极化法研究了纳米晶Ni和不同Co含量的纳米晶Ni-C0合金镀层在3.5%NaCl(质量分数,下同)和5%HCl溶液中的腐蚀行为.结果表明:通过脉冲电沉积法制各的Ni和Ni-Co合金镀层具有典型的纳米晶结构; 随着含Co量的增加,镀层的晶粒尺寸减小,硬度增加;所制备的纳米晶Ni-Co合金镀层组织结构均匀致密,其在3.5%NaCl溶液和5%HCl溶液中的耐蚀性均优于纳米晶Ni镀层;纳米晶Ni-Co合金镀层在3.5%NaCl溶液的浸泡腐蚀中腐蚀极少,表现出优异的耐腐蚀性能,而在5%HCl溶液中的腐蚀形态则为均匀腐蚀.     

7050铝合金应力腐蚀敏感性和钝化膜引起的膜致应力随电位变化的一致性（英文）

用流变应力差值法测量了不同极化电位下7050铝合金在3.5%NaCl水溶液(pH=10)腐蚀过程中表面钝化膜形成的拉应力,并用慢应变速率拉伸法测量了不同极化电位下的应力腐蚀敏感性。结果表明:7050铝合金在溶液中自然腐蚀时,表面钝化膜会产生一定的拉应力;阳极极化使表层拉应力明显上升,且随着电位升高应力增大;阴极极化时,当电位E≥-1100 mV时表层拉应力随着电位的升高而降低,当电位E≤–1100 mV时拉应力随着电位升高而升高。应力腐蚀敏感性随外加电位变化规律和钝化膜引起的附加拉应力变化完全一致。     

AZ80镁合金与异种合金的电偶腐蚀研究

在3.5%NaCl溶液中将AZ80镁合金与石墨、铝合金、锌合金、铜合金、Q235碳钢偶合进行电偶腐蚀。在电偶腐蚀过程中测量溶液pH值及电偶电流,用失重法计算AZ80镁合金的电偶腐蚀速率,并用XRD分析腐蚀产物成分。结果表明:3.5%NaCl溶液的pH升高并在10.5左右达到平稳且腐蚀产物以Mg(OH)2为主;电偶腐蚀加快AZ80镁合金腐蚀;电偶对阴阳面积比越大,AZ80镁合金电偶腐蚀越严重。     

自抛光防污涂层中铜离子释放对铝合金基体腐蚀的影响

针对防污涂层中含铜防污剂对铝合金基体的腐蚀影响问题,采用动电位极化曲线和腐蚀失重的方法,研究5083铝合金在含不同浓度Cu2+的3.5%NaCl溶液中的电化学腐蚀行为,采用电化学交流阻抗方法研究自抛光防污涂层和不含铜防污剂的丙烯酸树脂基涂层对铝合金的屏蔽性能和腐蚀情况。结果表明,溶液中的Cu2+浓度低于70μg/L时,对5083铝合金的腐蚀速率影响不大,当Cu2+浓度超过此临界值时铝合金的腐蚀会显著加速;直接涂刷防污涂层的铝合金在3.5%NaCl溶液中浸泡4天就发生腐蚀,说明涂层中的防污剂Cu2O与NaCl溶液反应生成的Cu2+向涂层内部渗透对铝合金基体的腐蚀有负面影响。     

Effect of segregation on initiation of corrosion of aluminium sacrificial anode containing mischmetal

Abstract

The effects of rare earth (RE) elemental additions in the form of mischmetal, added into an Al–Zn–In sacrificial anode alloy, were studied in 3% NaCl solution. Scanning electron microscopy and energy dispersive X-ray analysis were employed to analyse the microstructure of all Al alloys. Potentiodynamic polarisation of the anode material and a model alloy that simulated the segregated grain boundary composition were also investigated. The results showed that the microstructure of Al–Zn–In–RE alloy exhibited a typical dentritic form with small precipitates in an Al matrix and eutectic in interdendritic regions. Preferential attack from anodic segregation produced the early pitting and minor element enrichment on the surface, thus activating the anodes. Thus, using a RE mischmetal, which is much cheaper than pure RE elements, Al–Zn–In–RE alloys obtained desirable electrochemical properties for Al sacrificial anodes.     

Effects of electrolyte components on properties of Al alloy anode

The effects of Na2SnO3, In(OH)3 and Na2SnO3+In(OH)3 on the properties of Al alloy anode were studied in alkaline medium at 25 ℃. The self-corrosion rate of Al alloy anode was studied by method of H2 immersed in aqueous medium, and the electrochemical properties of Al alloy anode were tested via galvanostatic discharge and dynamic potential methods. The results show that the self-corrosion rate of Al alloy anode in 4 mol/L NaOH+3 mol/L NaAlO2 medium can be minimized by adding Na2SnO3, In(OH)3 and Na2SnO3+ In(OH)3. Na2SnO3, In(OH)3 and Na2SnO3+In(OH)3 make Al anodic potential shift positively in galvanostatic discharging. The most effective additive of Al alloy anode in 4 mol/L NaOH+3 mol/L NaAlO2 medium is 0.075 mol/L Na2SnO3+0.005 mol/L In(OH)3, integrating self-corrosion rate and electrochemical properties.     

Al-Bi-Pb-In-Ga合金牺牲阳极的组织与电化学性能研究

研制了一种Nl-Bi-Pb-In-Ga合金牺牲阳极；用恒电流法研究了合金在自来水、淡海水、人造海水介质中的电化学性能；用金相显微技术和扫描电子显微技术观察牺牲阳极的微观组织和腐蚀后的表面形貌；结果表明，合金化元素均匀弥散分布的Nl-Bi-Pb-In-Ga合金牺牲阳极在自来水、淡海水、人造海水介质中腐蚀溶解均匀，阳极极化弱，电极电位负，阳极利用率高。     

A new electrochemical preparation method for formation Sm-Al alloys on inert Mo electrode from Sm2O3 in LiCl-KCl-MgCl2-KF molten salts

This work presents a new method for preparation of samarium alloy. Using Al rod as anode, electrochemical formation of Sm-Al alloy on Mo electrode from Sm2O3 in LiCl-KCl-MgCl2-KF molten salts was investigated. Samarium mainly exists in the form of Al2 Sm in Li-Mg matrix, and the concentration of Sm in this alloy runs up to be as high as 34.7%. The reaction of samarium preparation appears like a replacement reaction. The new preparation method makes possible a high samarium content in electrochemical deposition of Sm-Al alloy. Using Al rod as anode consumedly decreased the electrolytic cell voltage, and facilitated Sm deposition from Sm2O3 . This preparation method uses Sm2O3 as raw materials to gain samarium alloy directly, which could revolutionize the industrial production of samarium alloys.     

铸态及退火态Mg66Al34阳极镁空气电池的性能

制备了铸态及退火态Mg66Al34共晶合金,通过研究该合金的腐蚀及放电行为,考察了该合金作为镁空气电池阳极的放电性能。结果表明:在3.5 mass%NaCl溶液中,铸态合金具有较低的腐蚀速率及放电活性,退火态合金具有高的腐蚀速率及放电活性。在NaCl溶液中加入水溶性石墨烯后,铸态合金具有低的腐蚀速率及较高放电活性。铸态合金低的腐蚀速率是由于在β-Mg17Al12层间形成了黑色富铝氧化物腐蚀产物。     

海洋环境中铝合金表面改性涂层的电化学性能

目的对换热管用6061铝合金表面进行改性防护,研究一种在其表面具有牺牲性阳极保护效果且腐蚀速率小的涂层材料。方法采用线材火焰喷涂工艺在6061铝合金表面制备不同成分的锌铝涂层,分别为纯Zn、Zn50、Al95、Al、Al-RE共5种涂层,使用SEM、EDS、XRD分析测试方法对涂层形貌及成分进行分析,并测定涂层在3.5%NaCl溶液中的Tafel曲线。结果相同参数下在铝合金表面制备的涂层表观质量良好,无明显缺陷,符合热喷涂对于涂层质量的要求。常温环境下,Zn、Zn50、Al95、Al、Al-RE涂层的电位比6061铝合金的电位更负,5种涂层对6061铝合金都具有阳极性保护层的作用。结论从腐蚀电流和腐蚀电位考虑,Al95、Al-RE作为牺牲性阳极保护涂层的作用会更好。     

Effect of cooling ways on properties of Al/Pb-0.2%Ag rolled alloy for zinc electrowinning

In order to study the new anode materials for zinc electrowinning, Al/Pb-0.2%Ag rolled alloy was produced by composite casting and hot rolling. Then the effect of cooling ways on properties of Al/Pb-0.2%Ag rolled alloy was investigated. As the results of metallographic test indicated, with the increasing of cooling intensity, both Vickers hardness and yield strength of Al/Pb-0.2%Ag rolled alloy increase. Furthermore, the Al/Pb-0.2%Ag rolled alloy, cooled by ice salt, presents the finest grain size and shows the lowest oxygen evolution potential (1.5902 V), while that of alloy cooled by water and air are 1.6143 V and 1.6288 V, respectively. However, the corrosion current density and corrosion rate of the Al/Pb-0.2%Ag rolled alloy, cooled by ice salt, are the highest. This can be attributed to its largest specific surface area, which promotes the contact between the anode and electrolyte.     

A Review of Al Alloy Anodes for Al-Air Batteries in Neutral and Alkaline Aqueous Electrolytes

Aluminum-air(Al-air) batteries are promising candidates for energy storage applications because of their high theoretical energy density and low cost.Nevertheless,their developments have been severely hindered by multiple obstacles,among which the activation and self-corrosion inhibition of Al anode have been considered to be significant challenges.In neutral electrolytes,the main problem is the activation of Al anode,while the self-corrosion of Al anode becomes dominant in alkaline electrolytes.Considerable efforts have been devoted to overcoming the dilemma associated with the Al anode.This review firstly underscores the underlying mechanisms of passivation and self-corrosion of Al anode in different electrolytes.Then,specific attentions are paid to Al alloy anode,including the role of various elements and standard processing technology.Finally,general conclusions,current limitations,and future perspectives on Al alloy anode are presented.     

Study of aging and electrochemical behaviour of Al?Li?Cu?Mg alloys

Aging study of 1441 and 8090 Al? Li? Cu? Mg alloys exhibited characteristic precipitation hardening phenomena. Potentiodynamic polarisation studies carried out on various tempers of the 1441 and 8090 Al? Li? Cu? Mg alloys in 3.5% NaCl, with a small amount of H₂O₂, and in 3.5% NaCl solution with pH 10 and 12 showed the shifting of open circuit potential (OCP) towards more negative potential and higher corrosion rate, with the increase of aging time. The OCP value has shifted anodically with addition of H₂O₂ in 3.5% NaCl solution. Further, passivity phenomenon has been observed for all the alloy tempers in 3.5% NaCl solution at pH 10 and 12. The observation of OCP shift towards more negative potential and the higher corrosion rate with the increase of aging time has been attributed to the presence of higher amounts of anodic δ (AlLi), S′ (Al₂CuMg) and T₁ (Al₂CuLi) phases, studied by TEM, XRD and DSC methods.     

Effect of rolling processing on microstructure and electrochemical properties of high active aluminum alloy anode

The effect of rolling processing on the microstructure,electrochemical property and anti-corrosion property of Al-Mg-Sn-Bi-Ga-In alloy anode in alkaline solution(80℃,Na2SnO3+5 mol/L NaOH)was analyzed by the chronopotentiometry (E-T curves),hydrogen collection tests and modern microstructure analysis.The results show that when the rolling temperature is 370℃,the electrochemical activity of Al anode decreases gradually with the increase of pass deformation in rolling,while the anti-corrosion property is improved in the beginning and then declined rapidly.When the pass deformation of rolling is 40%,the Al anode has good electrochemical activity as good as the anti-corrosion property and with the increase of rolling temperature,both electrochemical activity and anti-corrosion property of Al anode increase first and then decrease.When the rolling temperature is 420 ℃,the aluminum alloy anode has the most negative electrode potential of about-1.521 V(vs Hg/HgO)and the lowest hydrogen evolution rate of 0.171 6 mL/(min·cm2).The optimum comprehensive performance of Al alloy anode is obtained.