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MM: Fachverband Metall- und Materialphysik
MM 31: Postersitzung II
MM 31.24: Poster
Wednesday, March 16, 2011, 17:15–18:45, P5
Ti-based dendrite - nano/ultrafine eutectic composites: microstructure control via semi-solid processing — •Olga Shuleshova1, Norbert Mattern1, Wolfgang Löser2, and Jürgen Eckert1,3 — 1Institute for Complex Materials, IFW Dresden, Germany — 2Institute for Solid State Research, IFW Dresden, Germany — 3Institute of Materials Science, TU Dresden, Germany
Recently, considerable advances are achieved in ductilization of the inherently brittle high-strength materials, such as metallic glasses and nano/ultrafine eutectics, through incorporation of soft dendritic phase, which primarily solidifies from the melt and is subsequently embraced in a strong matrix. An enhanced mechanical properties results from cooperative interplay of the inhomogeneous microstructure with the different deformation mechanisms of the respective phases, and thus are inherently related to the volume fraction, spatial sizes, morphology and overall distribution of the ductile crystalline phase reinforcement. Present work explores the possibility to control these parameters via isothermal holding between the liquidus and solidus temperature followed by rapid cooling of the semi-solid mixture. Previously applied only for the metallic glasses composites this approach is adopted here for the Ti-Fe-(Nb) system, known to form nano/ultrafine eutectic at moderate cooling rates. Moreover, relative simplicity of this system allows to study the peculiarities of the microstructures accessible via semi-solid processing in tight connection with the high-temperature phase equilibria given by thermodynamic description of the corresponding systems.