TY - BOOK

T1 - Al-Cr-N thin film design for high temperature applications

AU - Willmann, Herbert

N1 - embargoed until null

PY - 2007

Y1 - 2007

N2 - In this PhD thesis the microstructural design of AlxCr1-xN thin films (0 0.7, however, in this work the cubic structure could be stabilized up to x=0.81 by epitaxial growth. The addition of Al improves the oxidation resistance and has a stabilizing effect on the Cr-N bonds. The onset of dissociation is shifted to temperatures >1000 °C where Al-Cr-N decomposes to form Cr via the intermediate step of Cr2N under the release of nitrogen. Polycrystalline Al0.68Cr0.32N films show precipitation hardening due to wurtzite AlN formation, however, causing reduced Cr-N bond stability. Suppressing precipitation by reduction of possible nucleation sites (i.e. single crystal films) or lower Al-content in the film results in a conserved hardness of 30 GPa up to 1000 °C.

AB - In this PhD thesis the microstructural design of AlxCr1-xN thin films (0 0.7, however, in this work the cubic structure could be stabilized up to x=0.81 by epitaxial growth. The addition of Al improves the oxidation resistance and has a stabilizing effect on the Cr-N bonds. The onset of dissociation is shifted to temperatures >1000 °C where Al-Cr-N decomposes to form Cr via the intermediate step of Cr2N under the release of nitrogen. Polycrystalline Al0.68Cr0.32N films show precipitation hardening due to wurtzite AlN formation, however, causing reduced Cr-N bond stability. Suppressing precipitation by reduction of possible nucleation sites (i.e. single crystal films) or lower Al-content in the film results in a conserved hardness of 30 GPa up to 1000 °C.

KW - Al-Cr-N Cr-Al-N STA DSC TGA MS XRD HR-XRD HT-XRD TEM STEM thin film coating precipitation decompositions epitaxy RSM PVD arc evaporiation magnetron sputtering

KW - Al-Cr-N Cr-Al-N STA DSC TGA MS TEM XRD Ausscheidung Phasentransformation Epitaxie Schichtwachstum Dünnschichttechnik Lichtbogenverdampfung Kathodenzerstäubung

M3 - Doctoral Thesis

ER -