Abstract: A process for coloring a metal surface and colored metal products thus produced. The process involves forming a layer of a metal oxide on a surface of the metal to be colored and then bringing about permanent plastic deformation of the surface. If the oxide layer is of a suitable thickness (e.g. 500.ANG.-1 .mu.m) and the deformation is sufficiently high (preferably producing a reduction in thickness of the metal article by 30% or more), the resulting metal article exhibits an attractive color (usually a dichroic pastel color). The article can then be fabricated into finished articles, e.g. beverage cans, in the usual way.
Type:
Grant
Filed:
October 15, 1991
Date of Patent:
April 13, 1993
Assignee:
Alcan International Limited
Inventors:
Bryn Chamberlain, Harry Sang, Dan Fern, Prasad Apte, Lorne D. Kenny