Sliding Wear Behavior Solid Lubricant Based Ni–Al–Bronze Surface Composite Developed by Friction Stir Processing

Abstract

In this study, a nickel aluminium bronze (NAB) metal matrix composite reinforced with solid lubricants i.e. graphite and molybdenum disulphide (MoS2) was prepared by friction stir processing. Friction stir processing (FSP) refined the grain structure as compared to the as-cast NAB. The micrographs of graphite reinforced matrix revealed fine globular α phase with some elongated morphology α phases, whereas MoS2 reinforced surface composite mainly exhibited fine α phase particles. FSP also resulted in the distribution of solid lubricant particles in the NAB matrix. The hardness of the composites decreased with the addition of the solid lubricants in NAB matrix. SEM–EDS analysis of the reinforced NAB matrix confirmed the presence of solid lubricants. The influence of solid lubricants on the sliding wear behavior of NAB metal matrix was investigated by using the design of experimental approach. The experimental results revealed better wear resistance of the NAB–MoS2 surface composite as compared to graphite reinforced and FSPed NAB surface. SEM–EDS analysis of worn out surfaces and wear debris were carried out for understanding the wear mechanism. © 2017, The Indian Institute of Metals - IIM.