Experimental analysis on tribo-performance of aluminum composites

Two-body abrasion is of critical interest in engineering applications due to the severity of material and dimensional loss. In the present work, composites were manufactured through advanced stir-casting route by reinforcing Al-Zn-Mg-Cu alloy with 0 to 20 wt.% alumina particles. Microstructures of the developed materials were characterized through optical and field emission scanning electron microscopic examinations along with energy dispersive spectroscopy analyses besides measurements of porosity and Vickers hardness. Experimentation on two-body abrasion was carried out over a wide range of loads (20-80 N) and sliding velocities (0.125-1.50 m s(-1)) against silicon carbide abrasive medium. Tribological performances of base alloy and composites were assessed via evaluation of wear rate and coefficient of friction (COF) in addition to the estimation of surface roughness (SR) of abraded specimens. Composites exhibited higher SR, but lower wear rate and COF than alloy; the extents of those increased with raising reinforcement quantity. With rise in load, wear rate and abraded SR of the developed materials rose but COF decreased. Influence of sliding velocity was nominal on material loss for composites unlike base alloy, whereas SR was found to increase considerably and COF diminished slightly at higher velocities for all materials. Influences of various in-situ and ex-situ parameters on observed tribo-responses were explained through identification of different wear micromechanisms which were established via extensive postwear analyses of surface topography, worn surface, debris, and abraded paper.