Dresden 2014 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 43: Liquid and Amorphous Metals II - Mechanical properties

MM 43.1: Talk

Wednesday, April 2, 2014, 11:45–12:00, IFW A

FeCoSiBNbCu bulk metallic glass with large compressive deformability studied by time-resolved synchrotron X-ray diffraction — •Mihai Stoica^1,2, Sergio Scudino¹, Jozef Bednarcik³, Ivan Kaban^1,4, and Jürgen Eckert^1,4 — ¹IFW Dresden, Institute for Complex Materials, Helmholtzstr. 20, D-01069 Dresden, Germany — ²POLITEHNICA University of Timisoara, P-ta Victoriei 2, Timisoara, Romania — ³Deutsches Elektronen-Synchrotron (DESY), FS-PE Group, Notkestr. 85, D-22607 Hamburg, Germany — ⁴TU Dresden, Institute of Materials Science, D-01062 Dresden, Germany

By adding 0.5 at.% Cu to the strong but brittle [(Fe_0.5Co_0.5)_0.75Si_0.05B_0.20]₉₆Nb₄ bulk metallic glass, fully amorphous rods with diameters up to 2 mm were obtained. The monolithic samples with 1 mm diameter revealed a fracture strain of 3.80 % and a maximum stress of 4143 MPa upon compression, together with a slight work-hardening behavior. An estimate of the temperature rise ΔT in the shear plane gives 1039 K, which is large enough to melt a layer of 120 nm. Mechanical tests performed in-situ under synchrotron radiation allowed the calculation of the strain tensor components, using the reciprocal-space data and analyzing the shift of the first (the main) and the second broad peak positions in the X-ray diffraction patterns. The results revealed that each atomic shell may have a different stiffness, which may explain the macroscopic compressive plastic deformation.