Investigations on dry sliding wear machining and corrosion behaviour of aluminium metal matrix composites

Abstract

Aluminium Matrix Composites are used as materials in automotive newlineindustries owing to their superior strength-to -weight ratio and stiffness. newlineAluminium reinforced with conventional ceramic materials such as newlineSiC / Al2O3 are gradually being implemented in the production of components newlinein automobile industry. Fly ash (SiO2, Al2O3, Fe2O3 as major constituents and newlineoxides of Mg, Ca, Na, K etc. as minor constituents) is one of the most newlineinexpensive and low density material which is abundantly available as solid newlinewaste byproduct during combustion of coal in thermal power plants. newlineThe present investigation focused on the utilization of fly ash in newlineuseful manner by dispersing it into aluminium to produce composites by a newlinemodified two step stir casting method to overcome the cost barrier for wide newlinespread applications in automotive systems. newlineIn view of increasing commercial interest in the production of newlinecomposites, an attempt was made to study the influence of process parameters newlinesuch as size and shape of the impeller model, weight percentage of fly ash and newlinewetting agent magnesium on the distribution of fly ash particles in Al matrix newlineand mechanical properties of composites. Composites were fabricated newlineemploying a modified two step stir casting method according toTaguchi L 9 newlinetechnique. A radial impeller with 0.7 IOD/CID (Impeller outer dia to Crucible newlineinner dia) ratio was found to ensure uniform distribution of fly ash particles in newlineAl matrix along with a little deposit of the slurry on the wall surface of the newlinecrucible. Addition of Mg up to 1.5% by weight to the composite slurry increases the wettability and thus increases the mechanical properties through newlinestrong interfacial bonding between fly ash particles and the matrix. newlineInvestigations on dry sliding wear behaviour of Al and Al - fly ash newlinecomposites as a function of fly ash particle content at two different load and newlinesliding speed conditions was carried out using a pin-on-disc. newline