QUANTITATIVE TEXTURE ANALYSIS IN PULSE REVERSE CURRENT ELECTROFORMINGOF NICKEL

The crystallographic texture of nickel deposits is known to be related to its magnetic and mechanical properties. However, up to now, most o f the texture analyses of electrodeposited nickels have been semi-quan titative and still use a nickel sulphate bath, which is mainly for dec orative industrial applications. In this paper, a quantitative texture analysis using ODF (orientation distribution function) has been carri ed out to study the effect of a pulse reverse current on the crystallo graphic texture of electroformed nickels, with the use of a nickel sul phamate bath, which is now commonly used for functional industrial app lications and micro-or precise components. It was found that the [100] fibre texture with different orientation densities was formed at diff erent on-times and off-times. With a constant off-time of 0.5 ms, an i ncrease in on-time led to a gradual decrease in the orientation densit y of the [100] texture, whereas with a constant on-time of 5 ms, an in crease in off-time has affected the change of the orientation density of the [100] texture in a more complicated manner. All of these phenom ena are considered to be related to the change of the amount of inhibi ting chemical species such as nickel hydroxide adsorbed on the cathode surface and the nickel deposition rate. (C) 1998 Elsevier Science S.A .