共查询到19条相似文献,搜索用时 176 毫秒
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目前,鲜见研究杂质元素含量对铝合金牺牲阳极性能影响的报道。浇铸了不同Si含量的Al-5.00Zn-0.02In-1.00Mg-0.05Ti-xSi-0.10Fe-0.01Cu(质量分数,%)铝合金阳极。采用电化学方法、电感耦合等离子体质谱仪(ICP-MS)和金相显微镜对不同Si含量阳极在海水中的形貌、Al,Zn元素溶解量及电化学性能进行了研究。结果表明:Si的加入改善了铝合金的组织均匀性,Al-5.00Zn-0.02In-1.00Mg-0.05Ti-0.09Si(%)铝合金中的等轴晶较多,阳极表面溶解均匀,电流效率达到92%以上;该合金阳极在0.1 mol/L NaCl溶液中浸泡2 h后的Al和Zn溶解量分别为23.00,4.40 g/L,在由海水和KI组成的溶液中浸泡2,48 h后的扫描电流峰值分别为27,36μA,耐蚀性较强。 相似文献
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针对油气田分离器用铝基牺牲阳极出现的电流效率低和局部掉块问题,采用正交试验法,依据国家标准加入不同含量的Zn,In,Mg和Ti等合金,开展合金元素含量对阳极电流效率及溶解性能影响规律研究,研制新型高效铝基牺牲阳极.结果 表明:Mg和Zn对电流效率的影响较大,In和Ti影响较小,各元素含量的变化对电流效率的影响趋势不同.Mg含量是影响阳极腐蚀均匀性的主要因素,Mg在铝合金阳极中会形成第二相,导致表面局部电位发生变化,进而形成微电池,加速局部腐蚀;而Ti具有细化晶粒的作用;若Mg和Ti2种元素搭配不当,会导致局部偏析,发生掉块问题.正交试验极差法分析可知,阳极的最优配方为0.5 %Mg-4%Zn-0.035 %In-0.045%Ti,能够显著提高阳极的电流效率,改善试样溶解的均匀性. 相似文献
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研究了Ga含量对Al-Zn-In-Mg-Ga-Mn牺牲阳极性能的影响规律及其在干湿交替条件下的活化机制。结果表明:Ga含量在0.02%(质量分数)时,Al-Zn-In-Mg-Ga-Mn牺牲阳极在干湿交替环境下综合电化学性能最佳。金相组织观察和腐蚀产物EDS分析得出,随着Ga含量的增加,Ga在晶界处富集,由于Ga的活化作用,晶界处优先溶解造成晶粒的脱落,电流效率急剧下降;活性元素Ga和In在溶解反应时发生共同沉积现象,破坏了基体表面氧化膜的完整性和致密性,有效地维持了阳极的活性溶解。 相似文献
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以"硅热还原法"生产的纯镁为原料,采用金属型铸造工艺浇铸了纯镁牺牲阳极,考察了纯镁牺牲阳极的杂质含量在熔铸过程中的变化趋势及其电化学性能和腐蚀形貌。结果表明:纯镁牺牲阳极杂质含量仍然保持较低水平,其电化学性能满足ASTM 843-2003的要求,电流效率最大值达到了54%;纯镁牺牲阳极的开路电位取决于α-Mg基体的电位,α-Mg基体固溶元素较少,电位较负,开路电位较高,其最大值达到了-1.74V(vs SCE)。 相似文献
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Z.L. Zhao S.Q. Yin Y.D. Liu Z.Q. Zhang R.F. Ren 《Materialwissenschaft und Werkstofftechnik》2019,50(9):1124-1130
The microstructures and corrosion resistance of two as‐cast alloys, aluminum‐10 wt.% silicon hypoeutectic alloy and aluminum‐20 wt.% silicon (weight percent) hypereutectic alloy are investigated by conventional casting, the scanning electron microscope equipped with oxford X‐ray energy dispersive spectroscopy system and transmission electron microscope are applied for analysis. The results show that the microstructures change from the strip‐like into lump shape with the increase of silicon content from 10 % to 20 %. The electrochemical polarization curves prove that the aluminum‐20 wt.% hypereutectic silicon alloy had the better resistance with the corrosion potential of ?1.414 V and corrosion current density of 5.41 ? 10?5 ampere compared with the aluminum‐10 wt.% silicon hypoeutectic alloy. 相似文献
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《材料科学技术学报》2020,(6)
The effect of indium alloying on the corrosion and discharge behaviors of Mg-Al-Zn-Ga alloys is investigated via materials characterization, immersion test and electrochemical methods. The results indicate that indium alloying can effectively modify the distribution of intermetallic phases in Mg matrix via promoting the segregation of Al in the form of Mg_(17)Al_(12) in matrix. The addition of indium can effectively activate Mg-Al-Zn-Ga alloy evidenced by increased hydrogen evolution volume and weight loss, negative shift of corrosion and discharge potentials, increase of corrosion current density, decrease of polarization resistance and promoted Faradic efficiency. Nonetheless, excessive indium alloying(2.0 wt.%) would strikingly deteriorate the electrochemical performance of Mg-Al-Zn-Ga anode due to the exorbitant active effect. The Mg-6 wt.%Al-3 wt.%Zn-1 wt.%Ga-1 wt.%In in as-cast state with acceptable corrosion rate and desirable discharge performance is a low cost, non-toxic and well-performance magnesium alloy, which is a promising anode materials for seawater-activated batteries. 相似文献
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新型铝合金阳极电化学性能与组织研究 总被引:18,自引:2,他引:16
研制了两种新型铝合金阳极材料;用恒电流方法和动电位方法测定了铝合金阳极在碱性氯化钠(25%KOH+3.5%NaCl)介质中的电化学性能;用金相显微镜、扫描电子显微镜观察了新型铝合金的微观组织和阳级溶解后的表面腐蚀状态。结果表明:固溶于铝基体的微量合金化元素Ga、In及其适量均匀分布的第二相,可以破坏铝氧化膜的致密结构,促使铝基体的正常溶解,减少铝阳极极化,使铝合金阳极的稳定电极电位变得更负;加入能改变铝基体中杂质的存在状态和降低杂质含量的合金化元素Mg等,可以改善铝阳极的腐蚀均匀性,降低自腐蚀速度,提高阳极利用率。 相似文献
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为了扩大铝阳极的应用范围,采用添加剂来降低其腐蚀速度,同时活化铝阳极.用塔菲尔曲线、线性扫描伏安法、恒电流放电等方法,研究了在4 mol/L KOH溶液中,NaAlO2及添加剂NaF对铝(99.999%)阳极电化学性能的影响.结果表明:NaAlO2对铝阳极有害,NaAlO2的浓度不要超过3 mol/L;但添加50 mmol/L NaF在3.5 mol/L NaAlO2 4 mol/L KOH中,则铝的腐蚀电流密度由23.7 mA/cm2降低到20.8 mA/cm2,电极电位由-0.75 V负移到-1.50 V,开路电位由-1.64 V负移到-1.68 V,电位滞后时间缩短,基本上恢复到铝在4 mol/L KOH溶液中的电化学性能. 相似文献
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铸造不同成分的铜锡合金,通过人为腐蚀,利用LSV(电位扫描)、XRD、SEM等多种手段进行分析,结果表明:1)含Sn量为10%左右的青铜器在酸性含Cl^-环境中易产生晶间腐蚀生成粉状锈,而20% ̄40%含Sn量的青铜合金无明显晶腐蚀现象出现;2)含Sn量高于10%的合金,在NaCl溶液中在低电位处出现欠电位阳极电流峰(UPC),且形成V型CaCl晶相的电极表面膜。在较正电位处,铜锡合金及纯铜出现主 相似文献
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铝合金船舶的腐蚀防护技术现状与展望 总被引:2,自引:0,他引:2
针对国内外铝合金船舶的船体、空舱、海水管路系统、艉板法兰等部位的铝合金腐蚀现状进行了调研分析,发现船体基本采用涂料+铝合金牺牲阳极的方法进行保护,效果良好;而空舱、海水管路系统和艉板法兰等部位,却因防腐措施不到位分别存在一定的腐蚀问题。文章结合青岛海洋腐蚀研究所多年积累的铝合金实海腐蚀研究资料,在对相应部位腐蚀问题客观分析的基础上,分别对铝合金船舶的牺牲阳极阴极保护、防腐防污涂层保护、微弧氧化处理和电绝缘保护等腐蚀防护技术,在使用过程中存在的问题以及相应应对措施进行了分析总结,同时对铝合金船舶各项腐蚀防护技术的发展前景以及需要解决的问题进行了展望。 相似文献
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提高海水温度对锌合金和铝合金牺牲阳极电化学性能的影响 总被引:1,自引:0,他引:1
研究了提高海水温度对锌合金和铝合金牺牲阳极电化学性能的影响。结果表明,锌合金和铝合金牺牲阳级的电化学性能都随着海水温度的提高而变劣;凡是发生晶间腐蚀的合金,其晶间腐蚀程度都随着海水温度的提高而加剧。低含铝量的锌-铝-镉合金阳极在70℃海水介质中,工作电位仍负于-1.010V,电流效率>80%,阳极工作表面溶解均匀,且不产生晶间腐蚀。 相似文献
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Oxide films are incorporated into melts by an entrainment process, and are expected to be present in most metals, but particularly cast Al alloys. The oxides are necessarily present as folded-over double films (bifilms) that are effectively cracks. Their effect on the electrochemical behaviour of cast Al-5Zn-0.02ln sacrificial anodes was studied in 3 wt pct sodium chloride solution using the NACE efficiency evaluation. Three methods were employed to entrain progressive amounts of oxide in the alloy, including the addition of Al-Zn-ln maching chips to the charge, increasing the pouring height, and agitating the melt. The introduction of oxide bifilms in the cast alloy resulted in the deterioration of the electrochemical properties of the sacrificial anodes, such as current capacity and anode efficiency, and introduced increasing variability in these properties. The results suggest that corrosion behaviour is strongly related to the presence of bifilms suspended in the liquid alloy because bifilms provide crack paths allowing the corrodant to penetrate deeply into the metal matrix, and simultaneously provide localized galvanic cells because of the precipitation of Fe rich intermetallic compounds on their outer surfaces. 相似文献
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In this study, effects of manganese and magnesium content on the electrochemical properties of Al-Zn-In sacrificial anode were studied in 0.5 mol/L NaCl solution (pH=5). The aluminum base alloy with different amounts of Mn and Mg were melted at 750℃, then casted at molds at 25℃. Corrosion experiments were mounted to determine the optimal eeeect of Mn and Mg on the effciencies of the aluminum alloy anodes. The corroded and unexposed sample surfaces were subjected to microstructure characterization by optical and scanning electron microscopy. Al-Zn-In alloy doped with 0%, 0.01%, 0.05%.0.2% and 0.3% by weights of Mn and 0%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5% and 3.0% by weights of Mg were prepared to determine the effect of Mn and Mg on anode effciency in the environment. The different microstructures of the evolved Al- Zn-In-Mg-Mn alloy were correlated with the anode effciencies. The Al-5.0%Zn-2.0%Mg-0.15%Mn-0.02%In gave the best anode effciency (about 83%). The microstructures of the corroded surface of the optimized alloy revealed decreased distribution of the pockets of localized attacks which are characteristics of pitting (or crevice) corrosion. 相似文献