Microstructural, physical and mechanical characterization of grinding sludge based aluminium metal matrix composite

Abstract

Listen

Translate article

In the present study, industrial waste has been used as reinforcement in pure aluminium to enhance the physical and mechanical properties. This can be effectively obtained by the creation of Aluminium Metal Matrix Composites (AMMC). The present research work is focused on the synthesis of grinding sludge (GS) based AMMC by powder metallurgy. The composites contain pure Al matrix reinforced with three different weight percentages of grinding sludge constituents (6, 16 and 29 wt%). After that, the microstructure, density, hardness and compressive strength at room temperature are investigated. The presence of AlFe and AlFe 3 inter-metallic compounds has been examined using SEM (scanning electron microscope) area mapping and XRD (X-ray Diffraction). The density and hardness of composite materials were calculated for all samples. It is observed that the sample with 6 wt% GS sintered at a temperature of 700 °C shows 23% rise in compressive strength than that of the matrix when deformed to 48%. The strengthening mechanism of this sample indicates that the load-bearing, dislocation strengthening and phase transformation are the main contributors. The hardening behaviour based on the flow curves obtained from experiments has been studied using the Voce equation. Further, a modified Voce equation incorporating sintering temperature has been established for the Al/6 wt% GS composite material. This equation predicts the flow stress with good agreement to experimental flow stress concerning average absolute relative error (AARE) ranging from 0.37% to 4.44%. • Al/GS composite has been synthesized using the powder metallurgy method. • Formation of new phases AlFe and AlFe 3 occurred in Al/GS composites at sintering temperature of 700 °C. • The fractured surface will show features of brittle failure. • Sample, a3(Al/6 wt%GS sintered at 700 °C) could be deformed by about 48% strain. • Modified Voce equation is developed to account for the effect of the sintering temperature.