Automatic transmission fluid corrosion inhibitor interactions with copper

Abstract

In this paper, a new method, measuring the change in resistance of a thin copper wire, has been applied to provide a way to monitor a corrosion reaction in situ. Two different corrosion inhibitors used in commercial automatic transmission fluids have been studied at 110 °C, 120 °C, 130°C, and 150 °C using this new test method coupled with a more traditional coupon test to allow surface analysis to be carried out. Both inhibitors were found to be equally as effective up to temperatures of 130°C; however, the evidence provided shows that at 150°C, the thiadiazole inhibitor is breaking down leading to severe pitting on the surface. Corrosion performance therefore, cannot be assumed to be effective at all temperatures, and the current method provides a convenient quantitative screening method for inhibitor evaluation.

The influence of model organosulfur extreme pressure additives and analogues on the corrosion of copper as measured by a wire corrosion test method

“…To follow reactions in situ a technique that uses a wire resistance measurement method is used for monitoring the corrosion process. [8][9][10][11] This paper compares a variety of model organosulfur EP additives with respect to corrosion of copper using this new technique.…”

“…Such information is useful in evaluating the impact of oil formulary on metals used in electrical circuits as well as traditional copper alloy hardware. To follow reactions in situ a technique that uses a wire resistance measurement method is used for monitoring the corrosion process 8–11 . This paper compares a variety of model organosulfur EP additives with respect to corrosion of copper using this new technique.…”