The Microstructure and Creep of an Extruded Mg-Y-Nd Alloy

  1. Prof. Dr.-Ing. K. U. Kainer
  1. Rasul Azari-Khosroshahi

Published Online: 15 MAY 2006

DOI: 10.1002/3527607552.ch112

Magnesium Alloys and their Applications

Magnesium Alloys and their Applications

How to Cite

Azari-Khosroshahi, R. (2000) The Microstructure and Creep of an Extruded Mg-Y-Nd Alloy, in Magnesium Alloys and their Applications (ed K. U. Kainer), Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, FRG. doi: 10.1002/3527607552.ch112

Editor Information

  1. GKSS-Forschungszentrum Geesthacht GmbH, Institut für Werkstofforschung, Max-Planck- Straße, D-21502 Geesthacht, Germany

Author Information

  1. Semnan University, Semnan, Iran

Publication History

  1. Published Online: 15 MAY 2006
  2. Published Print: 20 SEP 2000

ISBN Information

Print ISBN: 9783527302826

Online ISBN: 9783527607556

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Keywords:

  • magnesium alloys;
  • creep behavior;
  • microstructure;
  • extruded Mg-Y-Nd alloy

Summary

Microstructure of an extruded Mg-5.1wt%Y-1.9wt%Nd-0.9wt%HRE alloy in the T6 condition (WE54-T6) consisted of equiaxed grains together with homogeneously distributed plate shape β' and β” precipitates on prism planes of the alloy. By using extrapolation technique chemical composition of both β” and β' precipitates were identified.

Constant load creep tests were performed on heat treated alloy in the T6 condition, over the temperature range 230–270 °C and in the stress range 32–80 MPa. The values of apparent activation energy for creep (Qc) was found equal to 157±7 kJ mol−1 with stress exponent (n) of 4.3.

TEM examination of crept specimens revealed that both β”and β' precipitates transformed to plate-shape equilibrium β precipitates. Precipitate free zones were observed to develop along grain boundaries normal to the applied stress during creep testing. Fracture observations after creep testing revealed a mixed mode of fracture and brittle intergranular fracture predominated.