研究了钝化的纯铁在含 Cl^-的中性溶液中及304和321不锈钢在含 Cl^-的硫酸溶液中在低于孔蚀电位的恒电位条件下电流噪声的特征。结果表明,噪声电流峰具有线性上升而后按指数规律衰减的特征。在一定条件下噪声电流上升到最大值所需时间...研究了钝化的纯铁在含 Cl^-的中性溶液中及304和321不锈钢在含 Cl^-的硫酸溶液中在低于孔蚀电位的恒电位条件下电流噪声的特征。结果表明,噪声电流峰具有线性上升而后按指数规律衰减的特征。在一定条件下噪声电流上升到最大值所需时间ιc 大致恒定,但ιc 随电位的升高而增大。功率密度谱(SPD)曲线的截止频率都低于20Hz,表明孔核的发生、成长与再钝化过程是相当缓慢的过程。所有 SPD 曲线在极低频率下具有白噪声的特征,即功率密度的水平不随频率改变。随着频率的升高,SPD 曲线显示噪声转变为1/f^n 噪声。视腐蚀体系和控制的电位之不同,测得的表观 n 值在2~4之间。实验结果征实了前一篇文章中导出的 SPD 方程式[1]是适用的。讨论了表砚 n 值落在2~4之间的原因。展开更多
The mechanism of the electrolytic codeposition of Y Al alloy in molten LiF AlF 3 Al 2O 3 YF 3, LiF YF 3 Y 2O 3 AlF 3 and LiF YF 3 Y 2O 3 Al 2O 3 systems was investigated by means of cyclic volta...The mechanism of the electrolytic codeposition of Y Al alloy in molten LiF AlF 3 Al 2O 3 YF 3, LiF YF 3 Y 2O 3 AlF 3 and LiF YF 3 Y 2O 3 Al 2O 3 systems was investigated by means of cyclic voltammetry. The electrodeposited products were analysed by X ray diffraction. The results show that the electrolytic codeposition of Y Al alloy in the LiF YF 3 Y 2O 3 Al 2O 3 system without AlF 3 can be achieved at the same potential for Y(Ⅲ) and Al(Ⅲ) which have great difference in deposition potential. It is beneficial to codeposition of Y(Ⅲ) and Al(Ⅲ) when temperature rises. The potential of beginning codeposition is about -0.85 V ( vs Pt reference electrode), but only at the potential of -0.95 V or more negative can Y based Al alloy containing a great amount of yttrium be obtained.展开更多
The mechanism of the cathodic process of Y(Ⅲ) on platinum and molybdenum electrode in molten LiF YF 3 Y 2O 3 was investigated by means of cyclic voltammetry. The number of electron transferred was calculated. Th...The mechanism of the cathodic process of Y(Ⅲ) on platinum and molybdenum electrode in molten LiF YF 3 Y 2O 3 was investigated by means of cyclic voltammetry. The number of electron transferred was calculated. The results show that the electrochemical reduction of Y(Ⅲ) is a reversible one step three electrons reaction and the cathodic process is diffusion controlled. The reductive product easily forms the intermetallic compounds with the platinum electrode, but it is pure yttrium on the molybdenum electrode.展开更多
The mechanism of the cathode reduction of Ti(Ⅳ) at platinum electrode in molten LiF-NaF containingvarious concentrations of K_2TiF_6 has been investigated by means of cyclic voltamrnetry and convolutiontechnique. The...The mechanism of the cathode reduction of Ti(Ⅳ) at platinum electrode in molten LiF-NaF containingvarious concentrations of K_2TiF_6 has been investigated by means of cyclic voltamrnetry and convolutiontechnique. The transfered electron number of each reduction step has been determined. It is found that thereduction of Ti(Ⅳ) proceeds in three steps: Ti(Ⅳ)→Ti(Ⅲ)→Ti(Ⅱ)→Ti(0). The first step is accompanied bythe chemical disproportionation reaction: ZTi(Ⅲ)→Ti(Ⅳ)+Ti(Ⅱ). The cathodic product is soluble and prob-ably forrns alloy with the platinurn electrode.展开更多
文摘研究了钝化的纯铁在含 Cl^-的中性溶液中及304和321不锈钢在含 Cl^-的硫酸溶液中在低于孔蚀电位的恒电位条件下电流噪声的特征。结果表明,噪声电流峰具有线性上升而后按指数规律衰减的特征。在一定条件下噪声电流上升到最大值所需时间ιc 大致恒定,但ιc 随电位的升高而增大。功率密度谱(SPD)曲线的截止频率都低于20Hz,表明孔核的发生、成长与再钝化过程是相当缓慢的过程。所有 SPD 曲线在极低频率下具有白噪声的特征,即功率密度的水平不随频率改变。随着频率的升高,SPD 曲线显示噪声转变为1/f^n 噪声。视腐蚀体系和控制的电位之不同,测得的表观 n 值在2~4之间。实验结果征实了前一篇文章中导出的 SPD 方程式[1]是适用的。讨论了表砚 n 值落在2~4之间的原因。
文摘The mechanism of the electrolytic codeposition of Y Al alloy in molten LiF AlF 3 Al 2O 3 YF 3, LiF YF 3 Y 2O 3 AlF 3 and LiF YF 3 Y 2O 3 Al 2O 3 systems was investigated by means of cyclic voltammetry. The electrodeposited products were analysed by X ray diffraction. The results show that the electrolytic codeposition of Y Al alloy in the LiF YF 3 Y 2O 3 Al 2O 3 system without AlF 3 can be achieved at the same potential for Y(Ⅲ) and Al(Ⅲ) which have great difference in deposition potential. It is beneficial to codeposition of Y(Ⅲ) and Al(Ⅲ) when temperature rises. The potential of beginning codeposition is about -0.85 V ( vs Pt reference electrode), but only at the potential of -0.95 V or more negative can Y based Al alloy containing a great amount of yttrium be obtained.
文摘The mechanism of the cathodic process of Y(Ⅲ) on platinum and molybdenum electrode in molten LiF YF 3 Y 2O 3 was investigated by means of cyclic voltammetry. The number of electron transferred was calculated. The results show that the electrochemical reduction of Y(Ⅲ) is a reversible one step three electrons reaction and the cathodic process is diffusion controlled. The reductive product easily forms the intermetallic compounds with the platinum electrode, but it is pure yttrium on the molybdenum electrode.
文摘The mechanism of the cathode reduction of Ti(Ⅳ) at platinum electrode in molten LiF-NaF containingvarious concentrations of K_2TiF_6 has been investigated by means of cyclic voltamrnetry and convolutiontechnique. The transfered electron number of each reduction step has been determined. It is found that thereduction of Ti(Ⅳ) proceeds in three steps: Ti(Ⅳ)→Ti(Ⅲ)→Ti(Ⅱ)→Ti(0). The first step is accompanied bythe chemical disproportionation reaction: ZTi(Ⅲ)→Ti(Ⅳ)+Ti(Ⅱ). The cathodic product is soluble and prob-ably forrns alloy with the platinurn electrode.