Reactive magnetron sputtering of solid solution strengthened Al-Cr-O-N thin films


D. Diechle, M. Stüber, H. Leiste, S. Ulrich, KIT, Germany


Twelfth International Conference on Plasma Surface Engineering, 13 – 17 September 2010, Garmisch-Partenkirchen (Germany)


Posterpräsentation, PO2092, 14 September 2010, Poster Session 2


Hard, tough, wear and oxidation resistant thin film materials withstanding high temperatures and mechanical loads are important for tribological and tool applications. Ternary Al-Cr-O and related solid solution strengthened PVD thin films are promising candidates for such applications due to their thermal stability, chemical inertness and hot hardness. . New coatings from quaternary systems could even offer superior strength, hardness and toughness with regard to their mixed ionic and covalent bonds.


A new combinatorial approach to the design and growth of quaternary Al-Cr-O-N thin films by means of reactive r.f. magnetron sputtering will be presented. The deposition experiments were carried out with a Leybold Z 550 PVD machine by sputtering from a segmented Al-Cr target in an Ar-O-N atmosphere. The substrate temperature during deposition was adjusted to 500 °C. In this study the reactive gas flows and the substrate bias were systematically varied. Detailed results on the coatings composition, constitution, microstructure and properties will be presented and discussed in comparison to ternary Al-Cr-O thin films deposited under identical conditions. The nanocrystalline thin films were characterized by determining their micro hardness by Vickers indentation, their residual stress by curvature method, their density by X-Ray reflection (XRR), their chemical composition by electron probe microanalysis (EPMA), their microstructure by X-Ray diffraction (XRD) and their constitution by scanning electron microscopy (SEM) and transmission electron microscopy (TEM).