Wear Behavior of Al 2 O 3 and Graphite Particulates Reinforced Al6061 Alloy Hybrid Composites

This paper deals with the fabrication and evaluation of wear properties by introducing micro size Al2O3 and Graphite particulates into Al6061 alloy matrix. Al6061 alloy based hybrid metal matrix composites were prepared by stir casting method. 9 wt. % of Al2O3 and 6 wt. % of graphite were added to the base matrix. For each composite, the reinforcement particles were pre-heated to a temperature of 600 degree Celsius and then dispersed in steps of two into the vortex of molten Al6061 alloy to improve wettability. The Microstructural study was done by using Scanning Electron Microscope (SEM), which revealed the uniform distribution of Al2O3 and Graphite particles in matrix alloy. A pin-on-disc wear testing machine was used to evaluate the volumetric wear loss of prepared specimens, in which a hardened EN32 steel disc was used as the counter face. The results revealed that the volumetric wear loss was increased with increase in normal load, sliding speed and sliding distances for all the specimens. The results also indicated that the volumetric wear loss of the Al6061-9% Al2O3-6% Graphite composites were lesser than that of the Al6061 matrix. The worn surfaces were characterized by SEM microanalysis.