Characterisation of thick film Ti/Al nanolaminates

Titanium/aluminium nanolaminates, with repeat periods between 5 nm and 10 mm and an overall deposit thickness of up to 2 mm, have been produced by physical vapour deposition using both thermal and electron beam evaporation followed by quenching onto a rotating, heated substrate. Deposits were characterised using a range of techniques including energy filtered transmission electron microscopy and conventional electron energy loss spectroscopy. The microstructures of the nanolaminates was shown to vary according to substrate temperature and the relative thickness of the layers. All the samples contained a range of intermetallics both at the layer interfaces and in regions where the layered structure had broken down. Theories have been postulated to account for the presence of the intermetallics, including atomic impingement during deposition and diffusion. Fcc Ti was also observed in cross-sectional TEM specimens.