The use of isothermal calorimetry to measure corrosion rates of metals in contact with preservative-treated wood

Abstract

The purpose of this paper is to examine whether isothermal microcalorimetry can be used to determine the corrosion rates of metals embedded in wood. Metal fasteners were driven into dowels of wood treated with alkaline copper quaternary, a common wood preservative that increases the corrosiveness of wood. The dowels were stored in a nearly 100% relative humidity environment at 27°C for one year; throughout the exposure period, dowels were removed and the thermal power generated by the sample was measured in an isothermal calorimeter. Measurements over the 1-year exposure showed that the thermal power depended upon the wood moisture content and ranged from 0 to 200 µW. The heat, determined by integrating thermal power over time, was higher than expected compared with the total amount of mass lost due to corrosion at the end of the experiment. Despite this, the technique shows promise as a method to determine how changes in wood moisture content affect the corrosion rates of metals in contact with preservative treated wood.