Photothermal Beam Deflection Study of Titanium Metal Corrosion by a Hot Lubricant

Abstract

The applicability of the photothermal beam deflection (PBD) method in monitoring the corrosion of titanium metal by a perfluoropolyether lubricant was investigated in the 21°–270°C temperature range. The signal amplitude and rise time at lower temperatures (21°–150°C) were constant for a given amount of corrosion product. At higher temperatures (150°–270°C) thermal gradients in the sample cell caused correctable distortions of the PBD signal. The signal rise times in all cases were slow (1–2 s). Signal amplitude sensitivity to thermal gradients made kinetic measurements difficult, even on a long time scale. The PBD signal indicates that corrosion depends on the presence of molecular oxygen in the lubricant as well as upon temperature.