Formation of Colored Films on Titanium Plates by Laser Irradiation

Abstract

Titanium oxide films, which may be of various colors due to interference, can be formed on titanium plate surfaces by CO₂ laser irradiation under controlled oxygen content in the atmosphere.
The irradiated surface shows some irreguralities due to rapid melting and solidification, but it is harder than and thus superior to anodic oxide coatings on titanium in terms of wear resistance.
Just beneath the titanium oxide film is a hard fine-grained structure layer, which contains soluble oxygen.