Claims
- 1. An element comprising a substrate consisting of aluminum or an alloy thereof and having an anodized outer layer which forms a surface of the element, while a region of said surface has at least one visual property which differs from the corresponding visual property of adjoining portions of said surface and forms visual marking which is observable to the human eye, characterized in that said element exhibits said change in said at least one visual property substantially exclusively locally in a zone in which said anodized outer layer adjoins said substrate.
- 2. An element as claimed in claim 1, wherein a boundary layer between said outer layer and said substrate (6) in said region has a greater roughness than in adjoining portions of said surface.
- 3. An element as claimed in claim 1, wherein said zone has at least more cavities than does a corresponding zone of adjoining portions of said surface.
- 4. An element as claimed in claim 3, wherein material in said zone has a different crystal structure than material in a corresponding zone of adjoining portions of said surface.
Priority Claims (1)
Number |
Date |
Country |
Kind |
PCT/SG99/00123 |
Nov 1999 |
WO |
|
Parent Case Info
This is a divisional of application Ser. No. 09/869,675, filed Jul. 2, 2001, now U.S. Pat. No. 6,590,183, issued Jul. 8, 2003.
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