| 摘要 |
<p>Al alloys that have been anodised and subsequently coloured blue may retain this colouration on hydrolysis. The colour is imparted by immersion of object in bath contg. salt of heavy metal, e.g. CuSO4, and by electrolysis in alternating current. The object is then plunged into an aqs. boiling soln. contg. between 0.1 and 1 gm/l of alkaline metal silicate, e.g. Na2SiO3. Treatment time is between 1 and 45 mins. Conventional hydrolysing treatments have a tendency to degrade the blue colour.</p> |
