The role of enhanced grain boundary diffusivity in high-temperature diffusion of interstitial elements through metals was widely recognized but poorly characterized in most materials. An effort was made here to estimate the grain boundary diffusivity of oxygen in a near-α titanium alloy, Ti–6Al–2Sn–4Zr–2Mo–0.1Si, by explicitly incorporating microstructures obtained from electron back-scattering diffraction into an analytical model. Attention was focused upon near-surface diffusion behavior contributing to the rapid ingress of oxygen and possible crack initiation in high-temperature environments.

Estimation of Grain Boundary Diffusivity in Near-α Titanium Polycrystals. R.A.Brockman, A.L.Pilchak, W.J.Porter, R.John: Scripta Materialia, 2011, 65[6], 513-5