Ic. Vickridge et al., HIGH-DOSE HE IMPLANTATION IN 2 TI ALLOYS - EFFECTS ON STRUCTURE AND THERMAL-OXIDATION, Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms, 138, 1998, pp. 1068-1073
Implantation of inert gases such as helium into metals at sufficiently
high doses can lead to a variety of buried bubble structures. In this
work, motivated by the possibility of ultimately finding new or impro
ved catalytic surfaces, we investigate the thermal oxidation of Ti6Al4
V and of Ti15V13Cr3Al after implantation of helium at doses up to 2.5
x 10(18) ions cm(-2). The coexistence of various phases in the alloys
allows comparison of the different bubble structures formed in the dif
ferent phases under otherwise identical conditions of temperature and
dose. Using a combination of Nuclear Reaction Analysis (NRA), Rutherfo
rd Backscattering Spectrometry (RBS), Raman Spectroscopy and Transmiss
ion Electron Microscopy (TEM), we show that the buried helium structur
es survive thermal oxidation at 550 degrees C; that the crystalline ox
ide on both alloys consists only of mixed rutile and anatase phases; a
nd that the oxide formed on the implanted alloys has a higher proporti
on of anatase. (C) 1998 Elsevier Science B.V.