Cathodic Deposition Of Copper Research Articles

Natural convection mass transfer at horizontal screens

The free convection mass transfer behaviour of horizontal screens has been investigated experimentally using an electrochemical technique involving the measurement of the limiting currents for the cathodic deposition of copper from acidified copper sulphate solutions. Screen diameter and copper sulphate concentration have been varied to provide a range ofSc.Gr from 22×108 to 26×1010. Under these conditions, the data for a single screen are correlated by the equation:Sh=0.375(Sc.Gr)0.305 Results have been compared with previous work on free convection at horizontal solid surfaces where mass transfer coefficients are somewhat lower.

Ionic mass transfer by free convection with simultaneous heat transfer

Rates of electrochemical mass transfer by free convection under the influence of simultaneous thermal free convection have been measured for upward facing horizontal disc electrodes. The electrode reaction was the cathodic deposition of copper from cupric sulphate solutions containing H 2SO 4 as swamping electrolyte. Results have been correlated by the equations. ▪ and ▪ where GR m is a combined Grashof number for concentration and thermal buoyancy effects. ▪. Mass transfer has also been measured for the novel situation of nucleate boiling at the electrode surface and diffusion layer thicknesses as small as 1·7 × 10 −3mm have been obtained.

Kinetics of charge transfer at mechanically strained copper electrodes—II. Cathodic deposition

Current theories for the mechanism of metal deposition are briefly surveyed. It is shown that existing experimental evidence for surface-diffusion rate control at low η is unsatisfactory. The experimental method described in Part I permits the identification of the correct model and its quantitative verification. Results are presented for cathodic deposition of copper in the overpotential range 5–25 mV and at strain rates ranging from 4.7% to 91% per min. Equations are derived for the slow surface-diffusion model and the direct discharge model which relate the mechano-electrochemical deposition current to the strain. It is shown that for the former the current is directly proportional to the square root of the corrected strain; there is complex dependence for the latter. The results support the surface-diffusion model. The effect of strain rate is discussed quantitatively. For each overpotential, there is a limiting law that applies at high strain rates for all strains, and for all strain rates at sufficiently low strains. The deviation from this limiting law is attributed to the effects of thermal and electrolytic ‘healing’. The factor relating cd to strain is an order of magnitude smaller than for the anodic case; this difference is likewise attributed to the reduced activity of dislocations for deposition, because of healing. The conditions for the transition from the surface-diffusion control to charge-transfer control with solid electrodes are examined.

銅の陰極析出速度に及ぼす磁場の影響電解に及ぼす磁場の影響 (第2報)

The effect of the static magnetic field (solenoid) on the rate of cathodic deposition of copper from acidulated sulphate solution using insoluble platinum electrode is studied. In whole case, the rate of deposition in the magnetic field increases as compared with the case of non magnetic field. Particullary, the magnitude of the effect increases as the concentration of copper in electrolyte is diluted. By increasing the intensity of current density or magnetic field, the rate of deposition increases gradually.In case of alternating magnetic field, the tendency of the results is nearly proportional to that of the static magnetic field.The mechanism of the effect of magnetic field on the rate of cathodic deposition is discussed.

Studies on the Cathodic Deposition of Copper from its Alloys. (Report 1)

Studies on the Cathodic Deposition of Copper from its Alloys. (Report 1)