Production of a decorative surface comprises processing a metallic base material forming a submicroscopic thin oxide layer by etching, and deforming and heat treating to cause a specific recrystallization behavior

摘要

Production of a decorative surface comprises processing a metallic base material forming a submicroscopic thin oxide layer by etching; and deforming and heat treating to cause a specific recrystallization behavior with a corresponding grain growth. Preferred Features: The surface is mechanically sealed before etching. A mixture of concentrated H2SO4 and 40 % HF is used as the etchant at a temperature of 25 deg C for 4 minutes. An aluminum oxide protective layer is applied and post-sealed with water vapor.