Mobile sealing and repairing of damaged ceramic coatings by powder aerosol deposition at room temperature

Abstract

Repair instead of discard is going to be crucial in the vision of a green future, therefore we propose the powder aerosol deposition (PAD) as a promising technique to reprocess ceramic coatings at room temperature. Alumina coated copper substrates with an artificial imperfection are manufactured in a first step. In a second step, the repair of this imperfection is carried out using two different PAD apparatuses: first, a conventional PAD apparatus with a moving substrate holder and a converging slit nozzle and second, a miniaturized μPAD apparatus with a fixed substrate holder and a circular de-Laval nozzle. The different film profiles are studied using a laser scanning confocal microscope. Cross-sectional images to investigate the microstructure are taken by a scanning electron microscope. Finally, samples of both PAD apparatuses are exposed to an oxidizing atmosphere at 400 °C proving the gas-tightness as a further quality feature of the repair coating.

Keywords

• Aerosol deposition method (ADM)
• Room temperature impact consolidation (RTIC)
• Ceramic spray coating