Ti‐48 at. % Al powders of the metastable hexagonal‐closed‐packed solid solution with a grain size of 15 nm were prepared by mechanical alloying. The powders were consolidated to a density of greater than 99.5% by hot isostatic pressing (HIP) at 800 °C. After HIP the material exhibits a globular microstructure of the equilibrium phases α2 and γ with a mean grain size of 150 nm. Microhardness measurements show a Hall–Petch type [E. O. Hall, Proc. Phys. Soc. B 64, 747 (1951); N. J. Petch, J. Iron Steel Inst. 174, 25 (1953)] dependence on grain size. Room temperature compression tests reveal low ductility, but high fracture strengths ≥1800 MPa. On increasing the test temperature the yield strength drops sharply in the temperature range 600–800 °C to very low values. The results indicate that submicron‐grained TiAl alloys can be deformed at much lower temperatures than coarse‐grained material, making them suitable as precursors for net shaping, in particular if high deformation ratios are required. © 1995 American Institute of Physics.