Solutionizing Effects during Corrosive Wear in 6061 Aluminum and Composites

Abstract

Samples of commercial 6061 aluminum alloy in both the monolithic form and reinforced with 0.1 and 0.2 volume fraction of alumina particles were solutionized for 5, 10, and 20 h at 540 °C. A transient current generated in the composite material as a result of continuous and impact scratching during the corrosive wear process shows that composites are more sensitive to the microstructural changes taking place during solutionizing than is the monolithic 6061 alloy. The increase in grain size in the alloy during solutionizing does not significantly affect the transient current. Decohesion of the particles in the composites increases the interfacial area, and this interfacial region may act as an anodic site for corrosion to occur. Dislocations generated due to differences in the coefficient of thermal expansion values for alumina particles and aluminum matrix increase the measured transient current.