KINETICS AND MECHANISM OF THE HIGH-TEMPERATURE SELENIDIZATION OF TITANIUM

A titanium sheet was selenidized in selenium vapor of 1.33-13.33 kPa a t 823-973 K by means of a sealed-tube method. X-Ray diffraction patter ns and an electron-probe microanalysis of the product films showed the layer to comprise only TiSe2. Since the selenidization obeyed a parab olic rate law under all of the conditions employed, the rate-determini ng step was a diffusion process. The parabolic rate constant (K-p) cou ld be expressed as a function of the absolute temperature, and was app roximately proportional to the partial pressure of Se-2. A marker expe riment indicated that selenium was the component which diffused in the product film.