Artificial neural network analysis of preparation of nano α -Al 2 O 3 powders by thermal decomposition of ammonium aluminium carbonate hydroxide

Abstract

Nano α-Al₂O₃ powders were prepared by thermal decomposition of ammonium aluminium carbonate hydroxide (AACH). The effects of α-Al₂O₃ crystal seeds, reactant concentration, content of active agent (PEG), annealing temperature and ZnF₂ addition on the preparation of nano α-Al₂O₃ powder were studied. The results showed that nano α-Al₂O₃ powder with apparent crystallite size ∼40 nm could be prepared, and the complete transformation temperature of α-Al₂O₃ could be reduced from 1250 to 1050°C as α-Al₂O₃ seeds and ZnF₂ were added. The prepared nano α-Al₂O₃ powders were characterised by X-ray diffraction (XRD), differential thermal analysis and thermogravimetric (TG-DTA) and scanning electron microscopy (SEM). A back propagation (BP) artificial neural network (ANN) has been used to establish models between the relative content of the nano α-Al₂O₃ powders and the preparation parameters. The results of checking experiments were in accordance with the calculated values.