Constitutive behavior of Csf/AZ91D composites compressed at elevated temperature and containing a small fraction of liquid

Deformation behavior of 10 vol.% short carbon fiber reinforced AZ91D composite at the elevated temperature (596–696 K) and in the semi-solid state containing a small fraction of liquid (less than 10%) was investigated through compress test for the first time. The strain rate sensitivity and apparent activation energy in the semi-solid state are 0.2 and 392.3 kJ/mol respectively, which are higher than those in the elevated temperature. It is suggested that the presence of liquid phase causes the deformation behavior in the semi-solid state different from that at elevated temperature. The mechanical behavior of the composite can be characterized by the viscoplastic law in the elevated temperature. Considering the influence of liquid phase, a modified viscoplastic law was used to provide a unified description of the constitutive behaviors both at the elevated temperature and in the semi-solid state.