Abstract

Erosion-corrosion, a form of corrosion that rapidly attacks materials or equipment subjected to fluid flow, is a significant concern due to rapid failure within short periods. This occurs as a result of the combined action of erosion and corrosion. The research aims to study the effect of saline slurry jet flow on AA2024/SiC particulate composites saline slurry. The composite was produced using the stir casting method by incorporating SiC reinforcement with a particle size of 72 µm at 2, 4, 6 8 and 10wt% respectively. Artificial ageing was carried out at 190°C for 8 hours after solution heat treatment at 495°C for 1 hour to investigate effect of heat-treatment on erosion corrosion of test samples. The test samples were characterized using X-ray fluorescence (XRF), X-ray diffractometry (XRD), and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS). Subsequently, corrosion-erosion resistance was evaluated using a slurry jet impingement method with a modified Jominy hardenability tester. XRD analysis revealed the presence of aluminium matrix, copper aluminde (CuAl₂), S phase (Al₂CuMg), spinel (MgAl₂O₄), and silicon carbide phase (SiC) phases in the composite. XRF analysis indicated a composition of 91.4% Al, 3.7% Cu, 1.5% Mg, and 0.07% Mn. The erosion-corrosion tests established that flow velocity and the addition of solid erodent particles played a prominent role in the material removal rate. However, ageing treatment and the addition of reinforcement improved the samples' resistance. It was observed that increasing the flow velocity from 2 m/s to 5 m/s increased the mass loss. Mass loss also increased with the addition of silica sand erodent to the slurry. Further examination of the SEM micrographs of the eroded samples revealed surface deterioration from corrosion damage, manifested by pits of various sizes, grooves, and horse-shoe-like patterns.

Key words: Erosion-corrosion, impingement, slurry, jet flow, silicon carbide, jominy hardenability tester, silica sand.