Dynamic Recrystallization and Deformation Efficiency of Al-Based Composites

초록

The dynamic recrystallization behavior and deformation efficiency of Al 2024 and Al 6061 composites reinforced with 15 vol. % SiCp have been investigated at the temperature range of 320 to 520 ℃ and strain rate range of 0.1 to 3.0/sec by torsion test. Flow curve and deformed microstructure have been analyzed to identify the hot restoration mechanism of dynamic recrystallization(DRX) and deformation behavior. In order to suggest optimum hot working condition for DRX, contour map showing the variation of deformation efficiency expressed by [2m/(m+1)], where m is the strain rate sensitivity, with temperature and strain rate has been studied for the composites. Also, the deformation condition for DRX and peak efficiency of the composites were analyzed in relation to microstructural development. The Al 2024 composite showed 40∼50 % efficiency at the temperature range of 370∼460 ℃ under strain rates of 0.1∼0.5/sec, while the Al 6061 composite exhibited ∼40 % efficiency at the temperature range of 450∼500 ℃ under strain rates of 0.2∼0.5/sec. The variation of deformation efficiecny has been studied with the help of examining deformed microstructure and flow stress-strain curve.