The semi-solid casting method was applied for the preparation of Cu40Zr44Ag8Al8 amorphous composites.Effects of holding time on microstructure and mechanical properties of the amorphous composites prepared were investigated by X-ray diffraction（XRD）

simultaneous differential scanning calorimetry（DSC）and scanning electron microscope（SEM）

TEM

EPMA

uniaxial compression experiment.Results show that thermal stability of the amorphous matrix is reduced

and spherical particles in the composite are increased and refined

whereas the strength of the composites is declined with increasing in the holding time.Fracture analysis reveals that precipitation types in the composites is responasible for mechanical properties of the amorphous composites.Precipitation of the brittle intermetallic compounds Al3 Zr can take the change of stress concentration

leading to the decrease of the strength of the sample.