The intermetallic compound TiAl is a promising material for applications at high stress and high temperature. It has good balance between lightness, strength and oxidation resistance, but suffers of an intrinsic brittleness at lower temperature. Small, ternary additions of V, Cr or Mn are known to increase the ductility of this material. In the present and a recent study we have used electron energy loss spectroscopy as a sensitive test to investigate the electronic structure in these materials. The near edge structure (NES) may give complementary information to e.g. convergent beam electron diffraction (CBED) about the bonding character in these materials.
EELS spectra were collected using a Gatan 666 spectrometer with parallel recording fitted to a Philips CM 30 transmission electron microscope operating at a nominal voltage of 150 kV. The energy resolution (measured as full width at half maximum) was typically around 1 eV. Spectra from areas of similar thickness, as measured relative to the total inelastic mean free path of the 150-keV electrons were obtained.