The nucleation and growth of TiD2 in deuterium-implanted titanium

D(3He, alpha ) H nuclear reaction profiling and transmission electron microscopy data have been combined to produce a detailed picture of the nucleation and growth of TiD2 in Ti implanted with low-energy D. The TiD2 phase begins with the nucleation of submicron dia., coin-shaped platelets at densities of 1014 precipitates/cm3. The precipitates grow in size with increasing fluence while their density decreases. The larger precipitates therefore grow partially at the expense of smaller, less stable ones. The precipitates intersect at fluences of 1018 D/cm2, although the formation of a fully interconnected, stoichiometric surface layer of TiD2 does not occur until fluences exceed 1019 D /cm2.22 refs.--AA