engleski

Influence of the Addition of Waste Alumina Powder on Mechanical Properties of Alumina Ceramics

During the green machining of the alumina (Al2O3) green bodies, a certain amount of waste ceramic powder is generated which remains unused. In addition, the waste alumina ceramic powder should be disposed of as non-hazardous waste in a legally compliant manner. In this study, up to 20 wt.% Al2O3 powder was replaced by waste Al2O3 powder for the preparation of alumina ceramics green bodies by slip casting. Stable 70 wt.% Al2O3 – Al2O3 (waste) aqueous suspension was prepared for forming green bodies by slip casting in gypsum mould. Stabilization of concentrated aqueous alumina suspensions was achieved with the addition of 0.1 wt.% dispersant Tiron (expressed on dry weight basis of alumina powders). Green bodies were sintered by conventional method in electrical kiln from 1400 to 1600 °C. In this study, Response Surface Methodology (RSM) based on the Box-Behnken Design (BBD) was used to investigate the effects of addition of different amounts of waste alumina powder and sintering regime (sintering temperature and holding time) onto mechanical properties of obtained ceramic samples. Mechanical properties that were investigated are hardness and fracture toughness of sintered (Al2O3 – Al2O3 (waste)) samples.

waste alumina ; mechanical properties

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