Abstract
Hydration of commercially-pure Al powder in distilled water at 25 to 100℃ has been investigated. Bayerite
Al(OH)3 product layers formed on Al at 25-40℃ were porous, so the hydration rate, although very slow at 25℃,
increased rapidly with increasing temperature from 25 to 45℃. On further increasing temperature from 45 to
95℃, initial hydration rate increased, but changed little over long hydration periods due to formation of denser
and more continuous product layers. At 100℃, because of rapid water evaporation, hydration product layers (composed of Al(OH)3 and a small amount of boemite AlO(OH)) became detached from the Al surfaces, so offering
less production, so that the hydration rate of Al increased again.
