Auto-Ignition Combustion Synthesis of Calcium Aluminate Ceramic Powders

Abstract

Auto-ignition combustion synthesis (AICS) has been shown to offer the advantage of producing high purity, crystalline calcium aluminate powder using minimal experimental equipment and inexpensive starting materials in a relatively short time. Maximum combustion temperature, cooling rate and particle size were affected by the fuel content in the reactant mixture. The cooling rate of the powder product was observed to increase as fuel content increased from stoichiometric, while maximum combustion temperature increased followed by a consistent decrease with fuel contents beyond 1.5 times stoichiometric. Crystalline calcium aluminate powder with minimal phase change independent of fuel content was produced as determined from X-ray diffraction. SEM photomicrographs revealed that particle size was not significantly affected by fuel content while particle distribution and geometry appeared to be affected.

Keywords:

• Combustion synthesis
• Decomposition
• Powder production

Acknowledgments

The authors thank the Space Products Development (SPD) Program of NASA for support of this work.

Notes

*Determined experimentally.

Note that the negative value for O₂ suggests that O₂ is absorbed from the atmosphere to balance the chemical equation.