چكيده لاتين :
Hydration behaviour and antioxidising effect of aluminium (AI) powder has been
investigated. Bayerite AI(OH)3 product layers form ed on AI in pure water at 25-45 °C were
porous, so the hydration rate, although very slow at 25°C, increased rapidly with increasing
temperature from 25 to 45°C. On furth er increasing temperature from 45 to 95°C, initial
hydration rate increased, but changed little over long hydration p eriods due to formation of
denser and more continuous product layers. At lOO°C, due to rapid water evaporation, hydration
product layers (composed ofAI(OH)3 and a small amount ofboehmite AIO(OH) became detached
from the AI surf aces, so offering less protection, so that the hydration rate of AI increased
markedly. The presence ofMgO or calcium aluminat e cement (CAC) in water did not change the
hydration product, but greatly accelerate the hydration rate ofAI. Addition ofeven a small amount
(e.g. 0.25wt% ofAI amount) ofMgO or CAC to water accelerated significantly the hydration ofAI,
and with increasing level ofMgO or CAC, the hydration extent increased markedly. Sol-gel Si02
coatings on AI were useful in improving the hydration resistance ofAI, and did not have a negative
effect on the behaviour ofAI as an antioxidant.
