Production technology and properties of layered composite coatings used for boiling heat transfer augmentation

Abstract

The paper presents the production technology and properties of layered metallic composites in view of their use for the creation of highly efficient phase-change heat exchangers. It discusses the experimental results of the boiling heat transfer of distilled water and ethanol under atmospheric pressure on copper substrates on which a metal mesh layer, which augments heat transfer via boiling, was applied by sintering. The sintering technology enables durable bonds to be obtained between the joined elements, which results in proper strength properties. The meshes used in the experiments were made of bronze, brass and copper. The heat transfer results indicate that all the samples with the additional layer showed better performance - they dissipated more heat at the same temperature difference in comparison to the smooth surface without any mesh applied onto it, while the copper mesh outperformed the others. It seems to be linked to the highest thermal conductivity of this material in relation to the copper alloys considered in the study.