The phase diagram (see Figure 2) of TiAl contains many different intermetallic compounds, such as Ti3Al, TiAl, TiAl2 and TiAl3 (23). However, the research for structural materials has been concentrated to materials with two different bases; either γ-TiAl or α2-Ti3Al, as they have shown to have the potential to meet the design requirements needed for the intended applications (2). A third compound has lately been developed, orthorhombic intermetallics with Ti2AlNb as the base (4).