摘要
Oxidation of pure Ti coated with a thin Si layer was investigated to clarify the role of titanium silicide phases in improving oxidation resistance of titanium alloys. The system initially reacted to form a two-layer structure with Ti 5 Si 3 and SiO 2 . Oxidation proceeded by upward diffusion of Ti to form TiO 2 wedge-like crystals on the surface and inward oxidation of Ti 5 Si 3 into a mixed nanocrystalline TiO 2 and SiO 2 internal scale that was locally layered. The Ti 5 Si 3 phase inhibited oxygen inward diffusion, thereby limiting oxygen ingress into Ti and retarding inward Ti oxidation until the silicide layer was completely oxidized.