Synergistic effects of wear and corrosion for Al203 particulate-reinforced 6061 aluminum matrix composites

摘要

Wear corrosion of alumina particulate-reinforced 6061 aluminum matrix composites in a3.5 wt pct NaCl solution with a revised block-on-ring wear tester has been investigated. Thestudies involved the effects of applied load,rotational speed, and environments (dry air and3.5 pct NaCl solution) on the wear rates ofmaterials. Also various specimens with Al2O3volume fractions of 0,10,15, and 20 pct wereemployed in this work. Electrochemical measurements and electron micrographicobservations were conducted to clarify themicromechanisms of wear corrosion in such metalmatrix composites. Experimental results indicatedthat the wear rate of monolithic 6061 Al in eitherdry wear or wear corrosion was reduced by addingalumina reinforcements. However, the effect ofvolume fraction on wear rate is only minor in drywear, while it is significant in the case of wearcorrosion. Wear-corrosion tests also showed thatthe corrosion potential shifted to the active sideand the current density for an applied potentialincreased with the decrease of Al2O3 volumefraction in the materials and the increase inapplied load and rotational speed. Although theincorporation of reinforcement in these aluminummatrix composites was deterimental to theircorrosion resistance, the influence on wear corrosion was favorable.