Studies on corrosion behaviour of sintered aluminium based composites in chloride environment

Abstract

Aluminium matrix composites have been developed to replace other conventional engineering materials in specific industries where enhanced properties are required. The corrosion susceptibility of sintered unreinforced aluminium and composites in chloride medium (AMCs) were studied. The powders of pure as-received aluminium (matrix) and particles of ferrotitanium and silicon carbide particles were homogeneously dispersed using ball milling technique. Powder metallurgy route was utilised for consolidating the milled powders into a sintered compact. Microstructural examination of the compacted pure aluminium and composites confirmed an even distribution of the reinforcements in the aluminium matrix. The produced composites also recorded an improved corrosion resistance in a corrosive medium of 3.5 wt.% laboratory prepared sodium chloride, from the potentiodynamic polarization and chronoamperometry (potentiostatic) tests. The corroded specimens were further assessed for pitting using a field emission scanning electron microscope (FE-SEM). The resistance of the fabricated samples to corrosion was improved upon the addition of TiFe and SiC reinforcements.