Abnormal deformation behavior and particle distribution during hot compression of fine-grained 14 vol% SiCp/2014Al composite

The compressive deformation behavior of an extruded 14 vol% SiCp/2014Al composite fabricated by stir casting was investigated at temperatures of 355-495 °C and strain rates of 0.001-1 s−1. An abnormal variation of flow stress with temperature was observed at low strain rates. This anomalous behavior was attributed to abnormal grain growth in the matrix alloy above a critical temperature, resulting in higher deformation resistance of the composite at elevated temperatures. Furthermore, the effect of the compression parameters on the particle distribution was investigated by the marked trace lines. It was indicated that after hot deformation, the particle free bands (PFBs) were commonly observed in the hard-to-deform region and shear deformation region. Increasing temperature and strain rate hardly improved particle distribution uniformity, while large compressive strain could eliminate the PFBs.