f and volume fraction f . The flow stresses were obtained from the average stress in the range of yy > 0.1. In the fig-
ure, the average flow stresses in the crystal and amorphous
phases are also shown. The flow stress in the amorphous phase is almost independent of the crystal volume frac- tion. It is considered that the slight increase in the flow stress of the amorphous phase is attributed to the strain rate increase as a result of the volume fraction decrease of the amorphous phase. On the contrary, the flow stress in the crystal phase significantly increases as the crystal vol- ume fraction increases. The enforcement of the flow stress of the composite with the volume fraction increase results from the stress increases in the crystal phase and the in- crease of its fraction. The flow stress of the composite