| 摘要 |
<p>Metal articles are Zn plated using a soln. contg. 50-90 g/l Zn ions and a conductivity salt in a concn. up to 4M and having a pH of 1 or more, pref. 1-3.5, platinq being carried out at a current density of at least 0.5 but pref. not above 60 A/sq.dm, for at least 1 sec. - Pref. bath temp. is 15-35 deg.C. Pref. soln. also contains Si and the pH is 2.5 or more. pH is maintained using (ortho- or pyro-) phosphoric acid, (di)chloroacetic acid, bromoacetic acid, HCl or NaH2PO4. Conductivity salt is a chloride, sulphate or fluoroborate.</p> |
