Rezumat
A study of the pulse plating of chromium from standard chromic electrolyte in the regime of rectangular unipolar pulses (iavg = 0.1–2.0 A/cm2, τр = 0.1–20 s, 12.5 – 50.0% duty cycle) at Т0 = 50oС has been conducted. Under these conditions we investigated dependence of a current efficiency of chromium η from different parameters of a pulse current (duration τр, duty cycle (%), average current density iavg), controlling changes of the surface temperature. The results indicate that growth of surface temperature at the increase of i, in the range of applied pulse durations and current densities, is the factor influencing on: a degree of enhancement of η under pulse conditions; dependence of a current efficiency on current density. We demonstrate that the surface temperature depends on pulse duration (pause) at the same average current densities. The dimensional effect of rate of plating of chromium has been discovered (dependence of a current efficiency of chromium on the size of electrode surface). It is shown, that this effect is caused by the surface heat evolution.