Some novel aspects when manufacturing alumina films by the Aerosol Deposition Method (ADM)

Titelangaben

Moos, Ralf ; Schubert, Michael ; Exner, Jörg ; Hahn, Manuel ; Leupold, Nico ; Kita, Jaroslaw:
Some novel aspects when manufacturing alumina films by the Aerosol Deposition Method (ADM).
2017
Veranstaltung: 12th Pacific Rim Conference on Ceramic and Glass Technology (PACRIM 12) , 21.-26. Mai 2017 , Waikoloa, Hawaii, USA.
(Veranstaltungsbeitrag: Kongress/Konferenz/Symposium/Tagung , Vortrag )

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Abstract

With the Aerosol Deposition Method (ADM) dense ceramic films can be produced at room temperature directly from a ceramic raw powder. Many novel applications are possible using electrically insulating alumina films that are processed without high temperature sintering steps. In the first part, this contribution reports on the high temperature electrical insulation behavior of alumina ADM-deposited films. This is determined by a setup in accordance to ASTM D257 or IEC 60093. It will be shown that the processed films perform better than conventional alumina substrates as they are commercially available for thick-film technology. This may open up new applications. The second part reports on some observations that occur when substrate hardness and substrate roughness are systematically varied. Ductile substrates can be expected to give strong film anchoring, whereas high hardness substrates might require higher particle velocities to form adherent layers. In this study, four ceramic substrates (two types of Al2O3, sapphire, and LTCC) with different hardness and surface roughness were alumina coated in order to study the formation of an anchoring layer and their effect on the deposition rate. As a result, and in contrast to some literature observations, a much smaller anchoring layer compared to that found on metallic substrates was found on the hard ceramic substrates.