Chemical bonding and interlocking between hydratable alumina and microsilica after drying at 110 ℃ and firing at 800 ℃

摘要

Chemical bond changes between microsilica and hydratable alumina were studied by X-ray photoelectron spectroscopy and Fourier transformation infrared spectroscopy. The formation of Si-O-Al bond was detected by the decreased O 1s and Si 2p binding energy and the lowered vibration frequency of hydratable alumina with the addition of microsilica after drying at 110 ℃ and heating at 800 ℃. Furthermore, it was observed by scanning electron microscope that the interlocking structure developed between the particles of hydratable alumina and microsilica after drying at 110 ℃ and the sintering took place among the particles after heating at 800 ℃. Therefore, it is proposed that the increased strength of the castables after drying and heat treatment at intermediate temperatures was attributed to the presence of microsilica which resulted in the formation of Si-O-Al bond and interlocking structure between hydratable alumina and microsilica particles.