PROCESS FOR SEALING ANODIZED METALS WITH LITHIUM- AND FLUORIDE-CONTAINING SOLUTIONS FREE FROM HEAVY METALS

摘要

The invention concerns a method of compacting anodized metals without using heavy metals. The method is characterized in that: a) in a first step, the anodized metal is brought into contact for a period of between 3 and 30 minutes (for an anodizing layer thickness of 20 .mu.m) with an aqueous solution which has a temperature ranging from 15 to 35 ~C and a pH ranging from 5.0 to 6.5 and contains between 0.1 and 3 g/l lithium ions and between 0.1 and 5 g/l fluoride ions; and b) in a second step, the anodized metal is brought into contact for a period of between 5 and 30 minutes (for an anodizing layer thickness of 20 .mu.m) with water or an aqueous solution of substances which prevent the formation of a sealing coating, the solution having a pH ranging from 5.5 to 8.5 and a temperature ranging from 80 to 100 ~C.