Study of oxygen content in titanium alloys after exposure at elevated temperature

Abstract

Isothermal oxidation testing of near α titanium alloys VT18U, VT20, Ti6Al7Nb and Ti6242S was performed in air at 560 °С for 1000 hours. Parameters of diffusion layer on the alloy surfaces were studied by microhardness indentations, optical microscopy, X-ray diffraction analysis and nuclear microanalysis. It was established that concentration of oxygen in diffusion layer of tested alloys after oxidation differs significantly. An approach was demonstrated and validated by nuclear microanalysis data that allows comparative evaluation of the total concentration of interstitial impurities in the diffusion layer by the X-ray diffraction method.