Research Article

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

¹ Materials Design and Structural Integrity Research Group, Department of Metallurgical and Materials Engineering, Federal University of Technology, Akure, PMB 704, Nigeria
² School of Chemical and Metallurgical Engineering, African Materials Science and Engineering Network (AMSEN) and DST-NRF Centre of Excellence in Strong Materials; all University of the Witwatersrand, Private Bag 3, WITS, 2050 Johannesburg, South Africa
³ The African Academy of Sciences (AAS), P.O. Box 24916-00502, Nairobi, Kenya

^* e-mail: kalanemek@yahoo.co.uk

Received: 19 February 2020
Accepted: 21 April 2020

Abstract

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.