A wet-chemical process yielding reactive magnesium aluminate spinel (MgAl2O4) powder

作者：Li JG^*; Ikegami T; Lee JH; Mori T; Yajima Y

来源：Ceramics International, 2001, 27(4): 481-489.

DOI：10.1016/S0272-8842(00)00107-3

• sintering
• Mg-Al spinel
• chemical synthesis
• ammonium carbonate

Ammonium carbonate was used as the precipitant to synthesize Mg-Al spinel precursors from a mixed solution of magnesium and aluminum nitrates. The precursor, composed of crystalline ammonium dawsonite hydrate [NH4Al(OH)(2)CO3.H2O] and hydrotalcite [Mg6Al2(CO3)(OH)(16).4H(2)O] phases, transformed to pure spinel at similar to 900 degreesC via the decomposition of hydrotalcite at similar to 400-800 degreesC and a solid-state reaction between MgO (decomposed from hydrotalcite) and gamma -Al2O3 (derived from NH4Al(OH)(2)CO3.H2O) at similar to 800-900 degreesC. Sinterability of the resultant spinel powders was evaluated by the constant-rate-of-heating sintering method. The effect of calcination temperature on particle morphology and sinterability of the resultant spinel powders was investigated. Spinel ceramics of similar to 99% dense were produced by vacuum sintering at 1550 degreesC for 2 h from the powder calcined at 1100 degreesC for 2 h.

• 出版日期2001