发明名称 |
Process for electrolytically coloring aluminum or aluminum alloy workpieces comprises anodizing the workpiece to form a covering layer, treating layer with a direct current and coloring the workpiece in an electrolytic solution |
摘要 |
Electrolytic coloring of aluminum or aluminum alloy workpieces comprises anodizing the workpiece in an aqueous strongly acidic electrolytic solution using a direct current or alternating current with a current density of 0.5-3.0 A/dm<2> forming an oxidic porous covering layer; treating the covering layer with a direct current in a bath having a high conductivity of 200-600 mS/cm; treating with an alternating current in a modifying bath and coloring the workpiece in an electrolytic solution containing a metal salt as coloring agent. Process for electrolytically coloring aluminum or aluminum alloy workpieces comprises anodizing the workpiece in an aqueous strongly acidic electrolytic solution using a direct current or alternating current with a current density of 0.5-3.0 A/dm<2> forming an oxidic porous covering layer; treating the covering layer with a direct current in a bath having a high conductivity of 200-600 mS/cm; treating with an alternating current in a modifying bath and coloring the workpiece in an electrolytic solution containing a metal salt as coloring agent. The value of the direct current density is adjusted to at least three times the current density used during anodization but bot less than 2.0 A/dm<2>. The electrolytic solution used in the modifying bath contains a strong acid and an organic compound selected from polyalcohols, hydroxy acids or dihydroxy acids.
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申请公布号 |
DE19938180(C1) |
申请公布日期 |
2001.01.11 |
申请号 |
DE1999138180 |
申请日期 |
1999.08.17 |
申请人 |
ERBSLOEH AG |
发明人 |
JANKOWSKI, ADAM |
分类号 |
C25D11/12;C25D11/22;(IPC1-7):C25D11/22 |
主分类号 |
C25D11/12 |
代理机构 |
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