The influence of curvature on FLC’s of mild steel, (A)HSS and aluminium

In literature the influence of curvature on formability has been reported. This\ud paper shows results for four materials when an FLC is measured with increasing curvature. It shows the FLC increases for sharper curvature most notably with 20 [mm] tool diameter. The increase is negligible on the left hand side, moderate on the right hand side and large on the plane strain axis. It is thought that contact pressure plays a role here and preliminary simulations indicate that this is quite possible

Oxygen electrosorption on Ag(111) and Ag(110) electrodes in in NaOH solution

The first stages of the anodic oxidation of Ag(111) and Ag(110) electrodes in NaOH solution were studied by potential sweep voltammetry and ellipsometry. It was found that in the potential region studied, dissolution of silver species and electrosorption of oxygen occur. The (110) face is much more reactive to oxygen than the (111) face. On Ag(110) oxygen is reversibly adsorbed via a process of random deposition. The half-width of the adsorption peak indicates attractive lateral interactions in the chemisorbed layer

An intensity-monitoring technique for measuring ellipsometric transients

Intensity-monitoring techniques make possible the measurement of rapid changes in the ellipsometric parameters. Methods used hitherto have been suitable for measuring slight changes only and require prior knowledge of the Δ and Ψ values for the initial surface. It is shown that larger changes can also be measured and that the values of Δ and Ψ for the initial surface need not be known beforehand. To illustrate the method measurements are made relating to the anodising of a hanging mercury drop electrode in 1 mol dm−3 NaOH; under these conditions a thick oxide layer is known to be formed

Electrochemical formation and reduction of silver oxides in alkaline media

The anodic oxidation of silver electrodes in NaOH solution and the reduction of the silver oxides formed were studied by potential step chronoamperometry. Oxidation of Ag to Ag2O is a diffusion-controlled reaction, the diffusion control being established in the solid phase. Oxidation of Ag2O to AgO proceeds via a nucleation and growth-controlled process. The amount of AgO decreased with increasing step height. The current—time curves for this reaction have been analysed with the Kolmogoroff—Avrami equation. Reduction of AgO to Ag2O occurs initially on the outside of the electrode, and the rate of the reaction is limited by diffusion of ions across the thickening layer of Ag2O. Reduction of Ag2O to Ag proceeds via a nucleation and growth reaction

Initial stages of anodic oxidation of silver in sodium hydroxide solution studied by potential sweep voltammetry and ellipsometry

The first stages of the oxidation of polycrystalline silver electrodes in NaOH solutions were studied by potential sweep voltammetry and ellipsometry. Formation of bulk Ag2O was found to be preceded by dissolution of silver species and deposition of a surface oxide. The equilibrium oxide coverage depended on the electrode potential and occurred within a few seconds. Surface oxide formation probably took place via a process of random electro-deposition. No ageing effect was observed in the chemisorbed layer

Initial stages of anodic oxidation of silver in sodium hydroxide solution studied by potential sweep voltammetry and ellipsometry

The first stages of the oxidation of polycrystalline silver electrodes in NaOH solutions were studied by potential sweep voltammetry and ellipsometry. Formation of bulk Ag2O was found to be preceded by dissolution of silver species and deposition of a surface oxide. The equilibrium oxide coverage depended on the electrode potential and occurred within a few seconds. Surface oxide formation probably took place via a process of random electro-deposition. No ageing effect was observed in the chemisorbed layer

Initial stages of anodic oxidation of polycrystalline copper electrodes in alkaline solution

The first stages of the anodic oxidation of polycrystalline copper electrodes in NaOH solutions were studied by potential sweep voltammetry and ellipsometry. Formation of bulk Cu2O was found to be preceded by electrosorption of oxygen species, that occurs in two successive stages, each represented by a current peak, corresponding to a different submonolayer state with a different adsorption energy. This surface oxide was formed via random electrodeposition. The width of the first current peak indicates the presence of lateral attractive interactions in the chemisorbed layer. The surface layer did not show any ageing effect