Dresden 2017 – wissenschaftliches Programm
MM 69: Topical session: Dynamics, relaxation and deformation in deeply supercooled metallic liquids and glasses VII - thermodynamics and structure
MM 69.1: Vortrag
Donnerstag, 23. März 2017, 17:30–17:45, IFW A
Vibrating-reed mechanical spectroscopy of an electrodeposited Ni-P nanoglass — •Hans-Rainer Sinning1, Yulia Ivanisenko2, Tao Feng3, Di Wang2, Herbert Gleiter2,3, and Horst Hahn2,3 — 1Institut für Werkstoffe, Technische Universität Braunschweig, Germany — 2Institute of Nanotechnology, Karlsruhe Institute of Technology, Germany — 3Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology, China
A nanoglass with a composition near Ni83P17 consisting of nanometer-sized amorphous "grains" and amorphous interfaces between these grains was prepared by a multi-phase pulse electrodeposition technique. As-deposited films were cut into 1mm x 10mm stripes and studied by mechanical spectroscopy at frequencies between 0.1 and 3 kHz using the vibrating-reed technique. Temperature-dependent spectra of internal friction and elastic stiffness were measured between 100 and 800 K. A thermally activated relaxation peak was observed above 400 K, followed by some irreversible transformation around 500 K after which the relaxation peak disappears. This transformation prevents an accurate determination of the activation parameters, which can only roughly be estimated to be of the order of 1 eV and 1013 s−1. The relaxation may be discussed from different viewpoints either as a type of beta relaxation, or as an interface relaxation somehow analogous to grain boundary relaxation in polycrystals. A final crystallization effect was found in both elastic modulus and internal friction at 750 K, which is 150 K higher than the crystallization of a conventional, melt-spun Ni-P metallic glass.