Corrosion behaviour of garnet particulate reinforced LM13 Al alloy MMCs

This paper describes a study of the corrosion characteristics of LM13 Al alloy-based composites reinforced with various amounts of garnet particulates. The weight loss method was used and the corrodent was I M HCl solution at room temperature. The durations of the tests ranged from 24 to 96 h. Corrosion tests were performed on the unreinforced matrix alloy as well as on the various composites in both heat-treated and as-cast conditions. In each test, the corrosion rates of the unreinforced matrix alloy and the composites were found to decrease with duration of exposure to the corrodent. Solution heat treatment at 525degreesC followed by artificial aging at 175degreesC was found to improve the corrosion resistance of every specimen tested. Corrosion resistance was also found to improve with increase in garnet content. An attempt is made in the paper to explain these phenomena. (C) 20022 Elsevier Science Ltd. All rights reserved.