On the role of sliding load and heat input conditions in friction stir processing on tribology of aluminium alloy-alumina surface composites

Aluminium (AA5083)-alumina surface composites are prepared by friction stir processing in two conditions of heat input. The low heat (LH) input conditions is achieved at a rotational speed of 710 rpm and a traverse speed of 100 mm/min, and high heat (HH) input conditions are achieved at a rotational speed of 1400 rpm and a traverse speed of 40 mm/min. The tribological characteristics of aluminium alloy, friction stir processed (FSPed) alloy and FSPed surface composites against steel ball are studied at 5, 10 and 20 N load. While no significant influence is found on frictional behaviour, wear resistance of FSPed composites is superior to FSPed alloys. FSPed composites fabricated at HH input conditions exhibited improved wear resistance as compared to LH input condition. Adhesion and delamination are dominant wear mechanisms at 20 N. Debris particles are reduced in size and hydroxidated in sliding of surface composites.