Active Thermochemical Barrier Coatings Using Metal Oxides: First Experimental Results.

Area of Science:

• Materials Science
• Chemical Engineering
• Thermal Management

Background:

• Metallic components in high-temperature applications face significant thermal stress.
• Traditional thermal barrier coatings offer insulation but lack active temperature regulation.
• Reversible thermochemical reactions present a novel approach for active thermal management.

Purpose of the Study:

• To present a new concept for active thermal coatings utilizing reversible thermochemical reactions.
• To develop and test a reactive thermal barrier coating based on the redox reaction of cobalt oxide (Co3O4).
• To evaluate the cyclability and stability of the developed coating.

Main Methods:

• Development of a reactive thermal barrier coating using Co3O4.
• Testing of coatings with varying layers (1, 2, and 3) of Co3O4.
• Utilizing simultaneous thermal analysis (STA) to demonstrate coating activity and stability.
• Assessing the redox reversibility and enthalpy of reaction for Co3O4.

Main Results:

• Demonstrated the active thermal buffering capability of the Co3O4 coating through endothermic (heat storage) and exothermic (heat release) reactions.
• Co3O4 exhibits a high enthalpy of reaction (844 kJ/kg) and good redox reversibility.
• Coatings with 1, 2, and 3 layers of Co3O4 showed stable performance over five cycles.
• Simultaneous thermal analysis confirmed the effectiveness of the active thermal coating.

Conclusions:

• The developed active thermal coating based on Co3O4 redox reactions effectively buffers temperature fluctuations.
• The coating demonstrates good cyclability and stability for at least five cycles.
• This technology offers a promising solution for enhancing the durability and performance of metallic components in high-temperature environments.