Hot deformation behaviour of bamboo leaf ash–silicon carbide hybrid reinforced aluminium based composite

摘要

Isothermal compression testing of BLA-SIC hybrid reinforced Aluminium composites was performed on Gleeble 3500 thermomechanical simulator under different deformation temperatures (300–400 °C) and strain rates (0.01–1 s‑1). The flow behaviour and the softening mechanisms were established using the trend of the stress-strain curves, activation energy and microstructural examination. The results showed that flow stress increased with decreasing temperature; but was not entirely strain rate sensitive − a characteristic identified in some Al 6XXX based metallic systems. Also, uncharacteristic flow stress oscillations were observed at strain rates of 0.01 and 0.1 s‑1 while steady state flow stress was observed at 1 s‑1. The hot working activation energy was ∼290.5 kJ/mol which was intermediate to the range of 111–509 kJ/mol reported in literature for various Al based composites. It was proposed that at strain rates of 0.01 and 0.1 s‑1, dynamic recrystallization and/or dislocations-reinforcements interactions were the dominant deformation mechanism(s), while at 1 s‑1, dynamic recovery was predominant.