| Title |
The Effects of SiCp Volume Fraction on Microstructures and High Temperature Softening Behavior of AA2024 Composites Reinforced with SiC Particles |
| Authors |
고병철(Byung Chul Ko); 유연철(Yeon Chul Yoo) |
| Keywords |
Hot workability; Work hardening rate; Hot restoration; Dislocation density; Flow stress; Hot ductility |
| Abstract |
Hot torsion tests were conducted in the temperature range from 320 to 480℃ under a strain rate of 1.0/sec in order to investigate the hot workability of SiCp/AA2024 composites reinforced with SiCp reinforcements of different volume fractions(0, 5, 10, 15, 20, and 30 vol. %). Initial microstructures of the composites fabricated by powder metallurgy route were studied to analyze the effect of reinforcing volume fractions on the flow stress and work hardening rate of the composites during hot deformation. Hot restoration mechanisms, dynamic recrystallization(DRX) and dynamic recovery(DRV). of the composites were studied from the flow curves and deformed microstructures. The dislocation density in the matrix and the grain size of the composites were analysed by transmission electron microscopy(TEM). The DRX occurred in all the composites during the hot deformation at 370~430℃ under a strain rate of 1.0/sec. Also, the flow stress and the dislocation density of the composites increased with increasing the volume fraction of SiCp reinforcement, and the difference in flow stress between the composites reinforced with 15, 20, and 30 vol. % SiCp was small. Also, the hot ductility of the composites deformed at different temperatures was studied in relation to the volume fraction of SiCp. |