| 摘要 |
<p>The articles are coloured in an immersion bath, with heating, by forming a colour-yielding oxide surface layer, removing from bath and washing. Layer-formation in immersion bath is stopped by superimposing a D.C. backlash voltage on articles, as soon as desired colour effect is reached. Colour shade reached at moment of reversing polarity is fixed. Pref. after reversing polarity, articles are left some time, e.g. 2-5 min., in an immersion bath, before removing and cleaning. This treatment improves abrasion-resistance of coloured surface by consolidating the previously formed colour-coating. Backlash voltage can be superimposed by joining the -ve pole of a DC source to galvanic support.</p> |
