Effect of microstructure on creep behaviour of cast Mg97Y2Zn1 (at.%) alloy

0385500 - ÚFM 2013 RIV CH eng J - Článek v odborném periodiku
Garcés, G. - Onorbe, E. - Dobeš, Ferdinand - Pérez, P. - Antoranz, J.M. - Adeva, P.
Effect of microstructure on creep behaviour of cast Mg97Y2Zn1 (at.%) alloy.
Materials Science and Engineering A Structural Materials Properties Microstructure and Processing. Roč. 539, MARCH (2012), s. 48-55. ISSN 0921-5093. E-ISSN 1873-4936
Grant ostatní: Ministry of Science and Innovation(ES) MAT 2009-07811
Institucionální podpora: RVO:68081723
Klíčová slova: Mechanical characterization * Magnesium alloys * Casting * Creep
Kód oboru RIV: JI - Kompozitní materiály
Impakt faktor: 2.108, rok: 2012

The creep resistance of the Mg97Y2Zn1 (at.%) alloy in the as-cast condition and after a isochronal thermal treatment up to 560 ◦C is evaluated from 200 ◦C to 350 ◦C. The as-cast alloy shows a microstructure characterized bymagnesiumdendrites and a Long-Period Stacking Ordered Structure in the interdendritic regions. The heat treated alloy shows a fully lamellar structure within magnesium grains. In both cases, the stress dependence of the creep rate presents two different regions. For low temperature and/or high strain rates, the creep behaviour shows a high stress exponent (n = 11) and high activation energy. The alloy behaves as a metal matrix composite where the magnesium matrix transfers part of its load to the LPSO-phase. Moreover, the lamellar structure within the magnesium grains in the thermal treated alloy results in an additional barrier against creep deformation. At high temperature and/or low strain rates, creep is controlled by non-basal dislocation slip. The cast alloy showed higher creep resistance than the heat treated alloy at low stresses since the diffusion of Zn and Y atoms nucleate at Shockley partial dislocations inhibiting their movements.
Trvalý link: http://hdl.handle.net/11104/0215228