The fracture surface topography is indicative for the limited ductility. Fracture morphology of specimens after semi-solid forging exhibits a cleavage fracture (Fig.6 (b)). Typical cleavage fracture is observed clearly after forging at 1 050 °C (Fig. 6(c)), where the delaminating of precipitates and matrix is the principal mechanism for the nucleation of microcracks within the grains.