生物医用T42NG铁合金腐蚀性能研究

对生物医用的T42NG经3Crl3不锈钢复合构成的T42NG钛合金“双金属材料”，在常温常常压下3。5％的NaCl水溶液中，采用“三电极体系”实验装置运用恒电位法测定其阳极稳态极化曲线，对其电化学腐蚀行为进行了系统地研究。结果表明：经3crl3不锈钢复合后的T42NG钛合金，其电极过程的阳极稳态极化曲线几乎只有纯化区和析氧区，不易发生腐蚀。     

不锈钢在NaCl溶液和海水中的腐蚀行为

用动电位扫描法测定了几种不锈钢在３．５％ＮａＣｌ溶液和海水中的阳极极化曲线。研究了Ａ７２５Ｍ０２Ｔｉ及Ｒ１系列的不锈钢在二种腐蚀介质中的电化学腐蚀行为，并与含Ｃｌ－的Ｈ３ＰＯ４溶液中几种不锈钢的腐蚀特征进行了比较。结果表明，在不同的腐蚀介质中，各种不锈铜的腐蚀行为不同，铬、铂、镍等合金元素对不锈钢的耐蚀性能有很大影响。几种不锈钢在含Ｃｌ－的Ｈ３ＰＯ４溶液中其极化曲线具有典型的活化—钝化极化曲线的特征，而在３．５％ＮａＣｌ溶液和海水中，除了Ａ７２５外，其它几种不锈钢极化曲线上的钝化区很小或没有钝化区．Ａ７２５，Ｒ（１０）及Ｍ０２Ｔｉ等三种不锈铜均出现点蚀的情况．     

TiAl基合金铌碳复合渗后抗腐蚀性能研究

T iAl基合金的密度低强度高高温蠕变性能好,在航空航天汽车船舶领域有着广泛的应用。但是TiAl基合金在一些特殊介质中如酸、盐溶液中容易被腐蚀,为了解决此问题,常常需要对其进行一定的表面处理。本文对TiAl基合金进行双层辉光等离子铌碳复合渗处理渗技术,对复合渗后试样(记作TiAl-Nb-C)合金层组织成分进行分析,同时,研究其在不同腐蚀介质中的电化学腐蚀行为,绘制阳极极化曲线,并和原T iAl基材的腐蚀极化曲线进行比较分析。     

硫酸溶液中离子注入铅的铝电极的腐蚀行为

在弱极化区测量了 2 5℃时H2 SO4溶液中离子注入铅的铝电极的阳极极化曲线 .研究了Pb离子注入量对铝电极腐蚀速率的影响 .实验结果表明 ,当Pb离子注入量为 2× 1 0 1 7离子数 /cm2 时 ,2 # 铝电极的腐蚀速率最小 ,其耐蚀性最佳 .在此基础上 ,测量了 2 # 铝电极在 2 5～ 65℃时的阳极极化曲线 ,详细考察了温度对其腐蚀速率的影响 ,并给出腐蚀电流密度与温度T的关系式 ,求出腐蚀过程的活化能     

激光熔覆Ni+Cr_2O_3复合涂层的耐蚀性

研究了激光搭接熔覆Ni+Cr2 O3复合涂层在 0 .5mol/LH2 SO4 +0 .5mol/LNaCl水溶液中的电化学行为 .试验表明Cr2 O3粒子在激光熔池中发生了完全溶解 ,涂层具有胞状枝晶组织特征 .激光熔覆Ni+Cr2 O3复合涂层比单一熔覆Ni合金涂层和 2Cr13马氏体不锈钢基材具有更低的维钝电流密度和更宽的钝化区范围 ,明显改善了在该腐蚀介质中的抗点蚀能力 .     

316L不锈钢在西沙海洋大气环境下的腐蚀行为评估

采用循环阳极极化、电化学阻抗谱(EIS)和扫描Kelvin探针技术(SKP)评估了在西沙群岛苛刻海洋大气环境下,316L不锈钢经过不同时间暴露后的腐蚀行为。研究结果表明,暴露时间的长短对316L不锈钢的钝化行为没有显著影响。在极化曲线上均表现为阳极活化溶解特征,钝化膜失去保护作用,且暴露时间越长,不锈钢表面破损越多。同时随着暴露时间的延长,不锈钢表面微区的Kelvin电位整体分布下降,且趋向于不均匀分布,电位波动逐渐增大,这可能是由于钝化膜发生破裂进而发生点蚀以及腐蚀产物积累造成的。     

氮含量和环境温度对316L不锈钢耐腐蚀性的影响

研究低温条件下腐蚀溶液温度以及钢中氮含量对316L奥氏体不锈钢耐腐蚀性能的影响,在1mol／L H2SO4＋0．5mol／L NaCl的腐蚀液中,对氮含量为0．0095％～0．5575％的316L奥氏体不锈钢进行阳极极化曲线及电化学阻抗测量。结果表明,提高氮含量,316L奥氏体不锈钢耐蚀性增强;腐蚀液温度升高,316L奥氏体不锈钢耐蚀性减弱。     

激光熔敷钻基合金高温腐蚀的试验研究

本文对以2Cr13不锈钢为基础，表面经激光熔敷钴基金合金在高温PbSO4盐中的热腐蚀行为和机制，进行了深入的研究探讨。试验结果表明，经激光敷估基金合金，耐高温腐蚀性比原2Cr13钢提高2．5倍以上；耐磨性提高2倍以上。原因是获得细密枝晶＋多元共晶组织，大量Co能促进Cr2O3、CoO.Cr2O3致密保护膜的形成，阻碍S的扩散，因而提高了耐高温腐蚀性能。腐蚀机制是沿晶腐蚀，硫化一氧化循环进行造成剥落型破坏腐蚀。     

激光熔敷钴基合金高温腐蚀的试验研究

本文对以2Cr13不锈钢为基材,表面经激光熔敷钴基合金在高温PbSO_4盐中的热腐蚀行为和机制,进行了深入的研究探讨。试验结果表明,经激光熔敷钴基合金后,耐高温腐蚀性比原2Cr13钢提高2.5倍以上;耐磨性提高2倍以上。原因是获得细密枝晶+多元共晶组织,大量Co能促进Cr_2O_3、CoO.Cr_2O_3致密保护膜的形成,阻碍S的扩散,因而提高了耐高温腐蚀性能。腐蚀机制是沿晶腐蚀,硫化一氧化循环进行造成剥落型破坏腐蚀。     

镍钛合金表面含壳聚糖的钙磷复合涂层的仿生合成

将高浓度模拟体液5×SBF与壳聚糖溶液相互结合,在预处理后的镍钛合金基体上快速形成了含壳聚糖的钙磷复合涂层。电化学测试表明,钙磷涂层复合壳聚糖以后,阳极极化曲线中的钝化区变宽,击穿电位明显升高,涂层的抗腐蚀性增强。复合涂层在单倍模拟体液SBF中浸泡4d后,SEM、EDS对涂层的测试结果表明,复合涂层具有良好的生物活性。     

耐蚀合金材料点蚀及高温高压腐蚀性能研究

研究了镍基合金材料在高温高压腐蚀环境下的腐蚀性能以及在含氧化性离子溶液中的点蚀敏感性.采用了溶液浸泡法、电化学极化曲线方法进行试验,并结合扫描电镜以及能谱分析手段对两种镍基合金的腐蚀特性进行了研究.利用高温高压釜研究了在高温高压条件以及含H2S/CO2气体介质下材料的高温腐蚀性能以及试验温度的影响关系.依据相关标准在氯化铁溶液中进行了材料的点蚀敏感性研究.试验结果表明：G3合金的耐点蚀性能优于Incoloy 825,其点蚀临界温度高于50℃;两种镍基合金材料在FeCl3水溶液中的动电位极化曲线显示不同的腐蚀状态,Incoloy 825合金极化曲线中阳极曲线部分很平缓,无钝化区出现,极化度较低,G3阳极钝化区较明显,点蚀电位相对较高;高温高压腐蚀试验显示,随着温度升高,腐蚀程度加剧,腐蚀产物主要有NiS、FeS及CrO3等金属氧化物组成.     

烘烤对重铬酸盐封闭膜形貌和腐蚀行为的影响

铝合金阳极氧化后需进行封孔处理,烘烤极大的影响铝合金氧化膜的形貌和耐蚀性。本实验对2024铝合金阳极氧化经过重铬酸钾封孔处理后的膜进行烘烤研究。对烘烤过的试片与未烘烤的试片做电子显微镜表面形貌、激光共聚焦显微镜三维形貌及膜层的表面轮廓、膜的孔隙分布测试,且比较烘烤前后膜层的极化曲线。结果如下:铝合金阳极氧化重铬酸钾封闭后未烘烤膜的表面轮廓有很多非常深(深达18μm)、窄而细的孔,孔隙分布广而且密集;烘烤后封孔膜的孔隙深度降低,多孔层收缩变薄,孔隙分布稀疏。烘烤降低了重铬酸钾封闭膜的粗糙度且膜表面的凹坑有一定程度减少。从极化曲线看,烘烤后重铬酸钾封孔阳极钝化电流比未烘烤时低了几个数量级,说明烘烤提高了重铬酸钾封孔的铝合金的耐蚀能力。     

Electrochemical Behavior of Antimierobial Stainless Steel Bearing Copper in Sulfate Reducing Bacterial Medium

The electrochemical characteristic of antimicrobial stainless steel beating copper NSSAM3 in sulfate reducing bacterial(SRB)was investigated by electrochemical impedance spectroscopy(EIS)and potentiodynamic polarization.The results show that inoculation of SRB into the culture medium significantly affects the anodic polarization behavior of NSSAM3 and accelerates anodic depolarization process,however, it has little effect on cathodic polarization curves of NSSAM3.Under the same exposure time,the anodic polarization curves of NSSAM3 in culture medium with SRB are in anodic active dissolution state when anodic polarization potential value is below 0 V(SCE),whose anodic polarization current density is bigger than that of in culture medium without SRB.Moreover,when the concentration of Cu~(2 ) in SRB medium increases, anodic polarization current density of NSSAM3 decreases and polarization resistance increases with increasing time.Scanning electron microscope(SEM)observations indicate that SRB unevenly attaches on the surface of NSSAM3,and induces the sensitivity to local corrosion.     

Electroehemieal Behavior of Antimicrobial Stainless Steel Bearing Copper in Sulfate Reducing Bacterial Medium

The electrochemical characteristic of antimicrobial stainless steel bearing copper NSSAM3 in sulfate reducing bacterial （SRB） was investigated by electrochemical impedance spectroscopy （EIS） and potentiodynamic polarization. The results show that inoculation of SRB into the culture medium significantly affects the anodic polarization behavior of NSSAM3 and accelerates anodic depolarization process, however, it has little effect on cathodic polarization curves of NSSAM3. Under the same exposure time, the anodic polarization curves of NSSAM3 in culture medium with SRB are in anodic active dissolution state when anodic polarization potential value is below 0 V（SCE）, whose anodic polarization current density is bigger than that of in culture medium without SRB. Moreover, when the concentration of Cu^2＋ in SRB medium increases, anodic polarization current density of NSSAM3 decreases and polarization resistance increases with increasing time. Scanning electron microscope （SEM） observations indicate that SRB unevenly attaches on the surface of NSSAM3, and induces the sensitivity to local corrosion.     

Alternating pulse current in electrocoagulation for wastewater treatment to prevent the passivation of al electrode

A novel current feed style, alternating pulse current, was proposed in electrocoagulation aiming at preventing the passivation of electrode materials. The open circuit potential （OCP） measurements after anodic and cathodic potentiodynamic polarization showed that cathodic polarization could activate Al electrode. The surface of Al electrode after alternating pulse current electrocoagulation was investigated by scanning electron microscope （SEM） and X-ray photoelectron spectroscopy （XPS）, and the results indicate that passivation of Al is not observed. Furthermore, the simulated wastewater treatment tests show that alternating pulse current electrocoagulation has a visible energy saving effect and is worthy of generalization.     

Alternating Pulse Current in Electrocoagulation for Wastewater Treatment to Prevent the Passivation or Al Electrode

A novel current feed style, alternating pulse current, was proposed in electrocoagulation aiming at preventing the passivation of electrode materials. The open circuit potential (OCP) measurements after anodic and cathodic potentiodynamic polarization showed that cathodic polarization could activate Al electrode. The surface of Al electrode after alternating pulse current electrocoagulation was investigated by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS), and the results indicate that passivation of Al is not observed. Furthermore, the simulated wastewater treatment tests show that alternating pulse current electrocoagulation has a visible energy saving effect and is worthy of generalization.     

Corrosion and Electrochemical Behavior of Zn-Cu-Ti Alloy Added with La in 3% NaOH Solution

The corrosion mechanism of Zn-Cu-Tialloy added with La in 3% NaOH solution was investigated by electrochemicaltesting and SEM observation.Polarization curves manifested that the overallcorrosion kinetics of alloys are under anodic control.The anodic passivation of the Zn-Cu-Tialloy is remarkably improved by the addition of La.Because La can effectively improve the hydrogen evolution/oxygen reduction over-potentialof alloy elements,and the rare earth oxide film plays an important role in insulation that can strengthen the dielectric properties of Zn-Cu-Tialloy,the corrosion resistance of Zn-Cu-Tialloy is made significantly better by adding a trace amount of La.The improvement of corrosion resistance is not positively correlated with the adding amount of La to alloy.The Zn-Cu-Ti-0.5La alloy displays the best corrosion resistance behavior.The corrosion form of the alloys mainly belongs to a selective corrosion and the main solid corrosion products are Zn(OH)_2 and ZnO.     

Electrochemical Behavior of Antimicrobial Stainless Steel Bearing Copper in Sulfate Reducing Bacterial Medium

The electrochemical characteristic of antimicrobial stainless steel beating copper NSSAM3in sulfate reducing bacterial(SRB)was investigated by electrochemical impedance spectroscopy(EIS)and potentiodynamic polarization.The results show that inoculation of SRB into the culture medium significantly affects the anodic polarization behavior of NSSAM3 and accelerates anodic depolarization process,however,it has little effect on cathodic polarization curves of NSSAM3.Under the same exposure time,the anodic polarization curves of NSSAM3 in culture medium with SRB are in anodic active dissolution state when anodicpolarization potential value is below 0 V(SCE),whose anodic polarization current density is bigger than that of in culture medium without SRB.Moreover,when the concentration of Cu2 in SRB medium increases,anodic polarization current density of NSSAM3 decreases and polarization resistance increases with increasing time.Scanning electron microscope(SEM)observations indicate that SRB unevenly attaches on the surface of NSSAM3,and induces the sensitivity to local corrosion.     

混凝土中钢筋极化曲线特征分析

为避免极化曲线测试中平衡电位发生偏移,提出了阳极极化电流方法。根据锈蚀前后钢筋极化曲线特征分析对平衡电位发生偏移做出了合理解释,明确了相关影响因素。给出了基于阳极极化电流法的钢筋锈蚀临界极化电流密度及相应的腐蚀电流密度经验公式。试验结果表明,阳极极化电流方法能有效判别钢筋锈蚀,对应的临界极化电流密度为0.2μA/cm2。     

Ti6Al4V合金表面纳米管阵列的制备

以氢氟酸和铬酸为电解液,采用阳极氧化法在Ti6Al4V合金表面制备高密度的纳米管阵列.利用场发射扫描电镜、X射线衍射仪和X射线光电子能谱对多孔氧化膜的形貌和结构进行分析,利用极化曲线和电化学阻抗谱研究了电解液中CrO3的作用机理.结果表明:电解液种类决定能否形成多孔氧化膜,而电解液的浓度影响多孔氧化膜的形貌和孔径大小;纳米管阵列氧化膜主要由大部分非晶态组织的TiO2,Al2O3和少部分晶态的Al2TiO5,Al3Ti5O2,Al2O3组成,氧化膜内的Al,Ti原子比高于基体中的Al,Ti原子比;CrO3浓度的高低会影响氧化膜的结构.