Influence of a silicon-bearing film on the early stage oxidation of pure titanium

Abstract

Oxidation of pure titanium with and without silicon-bearing thin films was investigated using transmission electron microscopy, X-ray energy-dispersive spectroscopy, and nanoindentation to understand the initial stages of scale formation mechanisms. For pure titanium, results showed a two-layer oxide scale with dense outer and porous inner layers attributed to the simultaneous outward titanium and inward oxygen diffusion fluxes assessed through the use of a marker layer. Titanium specimens coated with Si before oxidation yielded a thinner oxide with an outer columnar scale and minimal porous inner oxide growth. These findings suggest that Si hinders oxygen transport to the oxide/metal interface, thus reducing overall oxide growth and oxygen ingress into the titanium metal substrate over short-term exposures.