| 摘要 |
<p>A coloured anodised film is formed on an aluminium (alloy) workpiece by (a) electrolytically pretreating the anodised workpiece to increase the thickness of the barrier layer of the anodised film, and (b) electrolytically colouring the workpiece, as cathode, in a bath contg. one or more metal salts, by passing d.c. with superimposed positive pulses between the cathode and a counter electrode. - The colouring rate is much higher than in conventional d.c. colouring processes and, by using a pulsed voltage, damage to the anodised film is avoided. Thus, colouring can be carried out for a time sufficient to give a deep colouration without peeling off of the anodised film.</p> |
