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DS: Fachverband Dünne Schichten

DS 28: Nanoengineered Thin Films I

DS 28.3: Vortrag

Donnerstag, 26. März 2009, 10:00–10:15, GER 37

Development of α-(Al_x,Cr_1−x)₂O₃ solid solution strengthened thin films by reactive magnetron sputtering — •Dominic Diechle, Michael Stüber, Harald Leiste, and Sven Ulrich — Forschungszentrum Karlsruhe GmbH, Institute for Materials Research I, Karlsruhe, Germany

Hard, tough, wear and oxidation resistant thin film materials are important for many applications such as cutting tools. We present a new combinatorial approach for the deposition of solid solution strengthened α-(Al_x,Cr_1−x)₂O₃ thin films by reactive r.f. magnetron sputtering in an argon-oxygen atmosphere. The deposition experiments are carried out with a Leybold Z 550 PVD machine for the sputtering from a segmented target (Al and Cr) at non-equilibrium conditions. We adjusted the substrate temperature to 500 ^∘C and we induced a substrate bias up to -400 V. The metastable thin films were characterized by determining their Vickers micro hardness, their residual stress, their chemical composition by Electron Probe Microanalysis, their microstructure by X-Ray diffraction and their constitution by scanning electron microscopy and transmission electron microscopy.

The chemical analysis revealed nearly stoichiometric (Al_x,Cr_1−x)₂O₃ composition and the largest Vickers micro hardness was 2620 HV0,05. A comparison of the measured X-Ray diffraction spectrum with the peaks of α-Al₂O₃ and α-Cr₂O₃ showed six Bragg peaks positioned between the α-Al₂O₃ and α-Cr₂O₃ peaks of the same crystal lattice plane. Thus we assumed corundum-type α-(Al_x,Cr_1−x)₂O₃ growth of the solid solution.