Abstract
An electrical resistance method was adapted to test both aluminum and zinc die cast materials in tap water, detergent solutions, and detergent solutions plus bleach. Since the rate of attack of these materials in aqueous media is sometimes low, with consequent small resistance changes, low resistance circuitry is necessary. Plotted data show comparative corrosion resistance of zinc and aluminum materials and establishes the technique satisfactory for the intended use. Conclusions reached are: (1.) In all three test media the aluminum-silicon alloy No. 13 and the aluminum-silicon-magnesium alloy No. A360 are superior to the aluminum-copper-silicon alloy (A380) and the zinc die-cast material (D3), (2.) In solutions of detergent (not chlorinated) a reasonable amount of inhibition is conferred by the silicates which are present, (3.) No. 13 (aluminum-silicon) alloy appears to offer the maximum resistance to corrosion and No. 360 (aluminum-silicon-magnesium) alloy the next best. (4.) The method offers a satisfactory laboratory means of comparing corrosion resistance of metals. 2.3.5
