High-Temperature Mechanical Behavior of Extruded Mg-Y-Zn Alloy Containing LPSO Phases

0398583 - ÚFM 2014 RIV US eng J - Článek v odborném periodiku
Onorbe, E. - Garcés, G. - Dobeš, Ferdinand - Pérez, P. - Adeva, P.
High-Temperature Mechanical Behavior of Extruded Mg-Y-Zn Alloy Containing LPSO Phases.
Metallurgical and Materials Transactions A. 44A, č. 6 (2013), s. 2869-2883. ISSN 1073-5623. E-ISSN 1543-1940
Institucionální podpora: RVO:68081723
Klíčová slova: magnesium alloys * Long Period Stacking Ordered structure * creep
Kód oboru RIV: JG - Hutnictví, kovové materiály
Impakt faktor: 1.730, rok: 2013

The high-temperature mechanical behavior of extruded Mg(97-3x)Y(2x)Zn(x) (at. pct) alloys is evaluated from 473 K to 673 K. The microstructure of the extruded alloys is characterized by Long Period Stacking Ordered structure (LPSO) elongated particles within the magnesium matrix. At low temperature and high strain rates, their creep behavior shows a high stress exponent (n = 11) and high activation energy. Alloys behave as a metal matrix composite where the magnesium matrix transfers part of its load to the LPSO phase. At high-temperature and/or low stresses, creep is controlled by nonbasal dislocation slip. At intermediate and high strain rates at 673 K and at intermediate strain rates between 623 K and 673 K, the extruded alloys show superplastic deformation with elongations to failure higher than 200 pct. Cracking of coarse LPSO second-phase particles and their subsequent distribution in the magnesium matrix take place during superplastic deformation, preventing magnesium grain growth.
Trvalý link: http://hdl.handle.net/11104/0226096