Berlin 2005 – scientific programme

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M: Metallphysik

M 12: Flüssige und amorphe Metalle III

M 12.6: Talk

Friday, March 4, 2005, 16:00–16:15, TU H111

TiNbCuNiAl nanocrystalline matrix composites with high strength and high elastic and plastic strain — •Uta Kühn, Nicolle Radtke, Annett Gebert, Norbert Mattern, and Ludwig Schultz — IFW Dresden, Institut für Metallische Werkstoffe, Postfach 270016, D-01171 Dresden, Germany

High-strength Ti-Nb-Cu-Ni-Al alloys were prepared via arc melting and injection casting into a metal mold with dimensions of about 30 mm in diameter and 10 mm in height and 3 mm in diameter and 50 mm in length, respectively. The structure of the arc-melted ingots and as-cast samples was characterized by X-ray diffraction, optical microscopy, and transmission electron microscopy. Room-temperature compression tests were carried out with an electromechanical testing device under quasistatic loading. The structure of the Ti-based alloys consisted of a bcc b-Ti type phase and a small amount of an unknown nanocrystalline interdendritic phase as well. The optimization of the Ti-based alloy composition is performed to achieve both high strength and high ductility. Compression tests reveal that the composites undergo work hardening and plastic deformation prior to failure. The best combination of strength and ductility was found for a mold cast Ti-Nb-Cu-Ni-Al alloy, which presents a fracture strength of more than 2000 MPa coupled with a plastic strain of 24 These features significantly improve the mechanical behavior of such composites and opens the possibility of obtaining tailored mechanical properties by controlling composition and solidification conditions.