  The fracture surface of a Ti3Al-based alloy is studied using both an atomic
force microscope and a standard scanning electron microscope. Results are shown
to be quantitatively comparable. Two fracture regimes are observed. It is shown
in particular that the roughness index characterizing the small lengthscales
regime is equal to 0.5. Furthermore, the large lengthscales fractal domain is
found to spread over nearly six decades of lengthscales.
