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Synthesis of Aluminum Oxide Platelets
Author(s) -
Hill Richard F.,
Danzer Robert,
Paine Robert T.
Publication year - 2001
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2001.tb00692.x
Subject(s) - calcination , boehmite , hydrofluoric acid , crucible (geodemography) , fluoride , aluminium , aqueous solution , materials science , inorganic chemistry , evaporation , oxide , aluminium oxides , chemical engineering , mineralogy , chemistry , metallurgy , catalysis , organic chemistry , computational chemistry , physics , engineering , thermodynamics
Aqueous solutions of boehmite and hydrofluoric acid (HF) were used to prepare homogeneous mixtures of alumina and aluminum fluoride. Calcination at temperatures as low as 1000°C resulted in the formation of well‐defined hexagonal‐shaped α‐alumina platelets. Containment of the aluminum fluoride by covering the calcination crucible promoted crystal growth presumably by a reaction of continuous evaporation–condensation of aluminum fluoride. Hexagonal‐shaped platelet α‐alumina was observed with average diameters ranging from 7 to 33 μm. Large platelets with a narrow size distribution and average diameter of over 25 μm were prepared by controlling the initial concentration of HF and the calcination time, temperature, and atmosphere.