Tribological properties, i.e., wear rate, coefficient of friction (COF), and roughness of worn surfaces of an Al-Mg-Zn-Cu alloy and its composite reinforced with 20 wt % Al2O3 particles developed by stir-casting method have been studied and compared under two-body abrasion considering four independent control factors, i.e., load, abrasive grit size, sliding distance, and velocity each at three different levels. Design of test conditions and analyses of output responses have been performed employing standard Taguchi L27 orthogonal array, signal-to-noise ratio, analysis of variance technique, and regression method. Irrespective of wear conditions, composite exhibits lower wear rate and reduced COF with reference to base alloy owing to the load bearing ability and better wear resistance capability of Al2O3 particles. Roughness of worn surfaces of composite is, however, found to be higher over base alloy due to nonuniform abrasion in case of composite that generates the protruded Al2O3 particles on contact surfaces as the surrounding soft matrix is easily removed. For all three tribo-responses of both materials, the most influential factor is identified as grit size followed by load and then, grit size-load interaction except for the roughness of worn surfaces where the influence of sliding distance is also considerable. Linear regression models with excellent predictability have been developed for all tribo-characteristics separately for base alloy and composite. The predominant mechanisms of abrasion are identified as plowing and microcutting for base alloy, but delamination for composite.
Mechanical and tribological properties of nano-sized Al2O3 particles on ADC12 alloy composites with Strontium modifier produced by stir casting method
