Corrosion Testing of Aluminum (Part 1 — High Velocity Test Method in Aqueous Solutions)

Abstract

Abstract A technique of corrosion testing, involving spinning of aluminum disks in aqueous solutions at high velocities, was used to investigate the effect of various natural waters and antifreezes on aluminum corrosion. Type of aluminum used was No. 100 aluminum brazing sheet, having zinc-aluminum cladding on one side, and silicon-aluminum cladding on the other. It was established that an increase in velocity of movement up to a maximum peripheral velocity of 4700 feet per minute (12,000 rpm) is accompanied by a systematic increase in corrosion rate reaching very high values in some waters. Type of corrosion occurring at higher velocities is similar to that occurring at low velocities and in service. Aqueous solutions particularly corrosive were those combining high chloride ion concentration and high alkalinity (as OH− or CO3= ion), such as Royal Oak, Michigan, tap water. High alkalinity (up to pH 11) appears to cause severe attack of aluminum even in the absence of chloride ion. In permanent antifreeze...