Oxide formation of a purified V–4Cr–4Ti alloy during heat treatment and ion irradiation

To investigate the effect of oxygen on the titanium oxide formation in V–4Cr–4Ti during heat treatment and also under irradiation, oxygen was gettered by Zr foils. After annealing and copper ion irradiation at different temperatures, the microstructure was investigated by transmission electron microscopy. Titanium oxides were detected by annealing between 973 and 1173 K, but the number density and size of the oxides decreased with the oxygen concentration. The temperature range corresponds to the temperature where long-range migration of titanium will occur. Ion irradiation revealed that residual oxygen atoms are very effective to titanium oxide precipitates formation in the temperature range of 773–973 K.