Evaluation of hot workability of particle reinforced aluminum matrix composites by using deformation efficiency

摘要

The high temperature deformation behavior of Al 6061 composites reinforced with SiC and Al2O3 particles has been studied in the temperature range of 300-550degreesC and the strain rate range of 0.1-3.0/sec by hot torsion test. The deformation efficiency eta, given by (2m/m + 1), where m is the strain rate sensitivity, is calculated as a function of temperature and strain rate to obtain iso-efficiency contour map. The composite reinforced with SiC particle exhibited a domain of dynamic recrystallization (DRX) with a peak efficiency of similar to40% at the temperature range of 450-500degreesC and strain rate range of 0.2-0.5/sec. On the other hand, the composite reinforced with Al2O3 particle showed the DRX domain at the temperature range of 450-480degreesC and strain rate range of 0.1-0.2/sec. The characteristics of these domain have been investigated with the help of microstructural observation and hot ductility measurements. (C) 2002 Kluwer Academic Publishers. [References: 15]