Nanostructured materials in multicomponent alloy systems

Citation
J. Eckert et al., Nanostructured materials in multicomponent alloy systems, MAT SCI E A, 301(1), 2001, pp. 1-11
Citations number
50
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
ISSN journal
09215093 → ACNP
Volume
301
Issue
1
Year of publication
2001
Pages
1 - 11
Database
ISI
SICI code
0921-5093(20010315)301:1<1:NMIMAS>2.0.ZU;2-X
Abstract
Production of bulk nanostructured composites with amorphous matrix revealin g a significant supercooled liquid region was carried out by die casting an d mechanical alloying (MA) and subsequent consolidation at elevated tempera tures. Multiphase materials with different volume fractions of nanocrystall ine precipitates were prepared from as-cast fully amorphous samples by isot hermal annealing. In contrast. MA powders were blended with insoluble metal lic and oxide particles upon milling. The different samples were analyzed b y X-ray diffraction (XRD), differential scanning calorimetry (DSC), scannin g electron microscope (SEM) and transmission electron microscopy (TEM), and viscosity measurements. The mechanical behavior of cast samples was invest igated using constant (true) compression rate tests at strain rates ranging from 1 x 10(-5) to 3 x 10(-3) s(-1). The Newtonian viscous how behavior of the composites at temperatures around T-g is mainly triggered by the homog eneous how of the supercooled liquid. The easy flow behavior above T-g was used to consolidate bulk dense specimens from mechanically alloyed composit e powders. Microhardness measurements at room temperature reveal a substant ial increase of the hardness of the composites due to the uniform distribut ion of nanoscale particles. (C) 2001 Elsevier Science B.V. All rights reser ved.