Erosive wear response of SiCp reinforced aluminium based metal matrix composite: Effects of test environments

Abstract

In the present investigation, the erosive wear behaviour of a 10 wt.% SiC particles reinforced aluminium based metal matrix composite has been studied. The composite was fabricated by dispersing SiC particles of size 50-100 µm into the matrix alloy. The resulting material cast was characterised in terms of microstructure, hardness and erosive wear behaviour. The wear response was examined by the sample rotation technique using the slurry pot erosion tester. The effects of speed, sand content and slurry environment on the slurry wear behaviour have been studied. It was observed from the microstructural studies that the interfacial bonding strength between the aluminium matrix and the SiC particles was good and the particles were distributed uniformly. Moreover, in basic medium matrix alloy exhibited a minimum wear rate compared to the composite whereas in the case of an acidic and saline medium, an improved wear resistance was obtained in the case of the composite. The rate of material loss is found to be higher with the increased sand concentration due to the increased impinging action of the sand particles. Also, the rotational speed has a mixed effect on the wear rate. It can be concluded that the material loss was caused by the synergistic effect of corrosive, erosive and abrasive actions of the slurry medium although in the acidic medium, erosion was the dominant mode of material removal whereas corrosion was dominant in the case of a basic medium.