Investigation of the Bonding Mechanisms of Al Coatings on Ceramic Substrates Deposited by Cold Gas Spraying and Magnetron Sputtering

Monday, May 11, 2015: 11:50 AM
Room 102C (Long Beach Convention and Entertainment Center)
Mr. Rico Drehmann , Chemnitz University of Technology, Chemnitz, Germany
Dr. Thomas Grund , Chemnitz University of Technology, Chemnitz, Germany
Prof. Thomas Lampke , Chemnitz University of Technology, Chemnitz, Germany
Prof. Bernhard Wielage , Chemnitz University of Technology, Chemnitz, Germany
Mrs. Christina Wüstefeld , Freiberg University of Mining and Technology, Freiberg, Germany
Dr. Mykhaylo Motylenko , Freiberg University of Mining and Technology, Freiberg, Germany
Mr. Gerhard Schreiber , Freiberg University of Mining and Technology, Freiberg, Germany
Prof. David Rafaja , Freiberg University of Mining and Technology, Freiberg, Germany
The present work builds on investigations of cold gas-sprayed Al coatings on Al2O3, which strongly indicated heteroepitaxial growth being one possible adhesion mechanism that takes effect at metal/ceramic interfaces. Following up on these results, the focus was laid upon the deposition of Al on further ceramic substrates (AlN, Si3N4, SiC and MgF2) in order to examine if the differing portions of ionic bonding in these substrate materials have an influence on interface formation. The investigations included a variation of substrate roughness, substrate temperature and powder fraction as well as a subsequent heat treatment. Furthermore, CGS coatings were compared to coatings produced by PVD. This allowed the detection of defects in the metal/ceramic interface solely caused by lattice misfit, without being overlapped by deformation-induced defects which are usually observed in thermally sprayed coatings. Interface characterization was conducted by scanning electron and high resolution transmission electron microscopy combined with XRD and EBSD.
See more of: Cold Spray Metals and Ceramics
See more of: Fundamentals/R&D