Berlin 2008 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 31: Application of Thin Films
DS 31.2: Vortrag
Donnerstag, 28. Februar 2008, 11:30–11:45, H 2032
Combinatorial development of ternary and quaternary shape memory thin film systems — •Robert Zarnetta1,2, Sigurd Thienhaus1,2, Alan Savan2, and Alfred Ludwig1,2 — 1Institut für Werkstoffe, Ruhr-Universität Bochum, Germany — 2Forschungszentrum caesar, Bonn, Germany
Current development goals for shape memory alloys in the area of conventional alloys are to decrease the transformational hysteresis to values below 5 K as well as to increase transformation temperatures to values above 100°C. In order to reach theses goals, thin film combinatorial and high-throughput technologies were applied. Ternary and quaternary materials libraries (continuous composition spreads) were deposited by optimized magnetron sputter techniques. The high-throughput characterization was performed by automated EDX (composition), XRD (microstructure), as well as temperature-dependent resistivity measurements revealing the phase transformation properties of the thin films. Temperature-dependent stress measurements on micro-structured cantilever Si-wafers with integrated 4-point resistivity measurement on each cantilever in a temperature range from -100°C up to 600°C were applied to characterize the actuator behavior. Results are presented for ternary Ni-Ti-X (X = Cu, Pd, Hf, Ag, ...) and quaternary Ni-Ti-Cu-Pd systems. Next to extending the knowledge about transforming compositions in ternary systems, special compositions or compositional regions with optimized properties were found.