Deformation efficiency and dynamic softening behavior of SiCp/Al 2024 composites

摘要

The deformation maps are constructed based on adynamic material model for hot working of extruded Al 2024composites reinforced with 15 vol. % SiCp at the temperaturesranging from 320 to 520℃ and the strain rates ranging from 0.1to 3.0/sec by torsion test. The values of strain rate sensitivity(m) ofthe composites were used for establishing the deformation maps.The efficiency of power dissipation, expressed as =2 m/(2 m+1), isplotted as a function of temperature(T), pass strain(εi), and strainrate(ε) to provide the optimum hot working condition for dynamicrecrystallization (DRX). Also, the DRX domain of the compositeshas been analyzed from the relationship between the efficiency anddeformed microstructure. With the increase in the deformationtemperature and the decrease in the strain rate, the efficiency of thecomposites increased. The characteristics of these results havebeen investigated with the help of hot ductility measurement andZener-Hollomon parameter(Z = ε exp(Q/RT)). It was found thatthe optimum hot working condition for DRX is 430~450℃ and 0.5/sec.