Mechanical properties, dry sliding wear resistance, and microstructural characterization of in-situ Al-17Si-Al3Zr/Al2O3 FG-composite synthesized via vertical centrifugal casting technique

Abstract

The goal of the current study was to develop functionally graded in-situ Al-17Si-Al3Zr/Al2O3 composites by approaching the vertical centrifugal casting method (VCCM). The two different proportion of Zr(CO3)2 powder (10 wt.% and 15 wt%) were added in to molten matrix to form the in-situ reinforced particles Al3Zr/Al2O3. The polyhedral shapes like Al3Zr and fine globular Al2O3 particles were formed into molten Al-17Si aluminum alloys. The accumulation of Al2O3 (ρ≈3.99 g/cm3) and Al3Zr (ρ≈4.11 g/cm3) in the vicinity of the outer zone was caused by centrifugal force. Additionally, particle coalescence and Ostwald ripening processes were found to be responsible for the clustering of eutectic silicon particles. The gradient distribution and morphologies of particles were characterized using SEM and OM microscopy. The constituent phases were analyzed via energy dispersive spectrometry (EDS) and XRD analysis. The hardness value was lower on the inner layers and higher on the outer layer. However, as compared to basic alloys, the hardness value of Al-15%Zr(CO3)2 increased by 64.7%. The dry sliding wear test involved the following variables: sliding velocities (m/s), sliding distances (m), and the normal applied load (N). The peak mass loss showed up with a load of 40N during wear property measurements. © 2024 Informa UK Limited, trading as Taylor & Francis Group.