58. Creep Properties of Mg Dispersion-Strengthened by Graphite

  1. Prof. Dr. K. U. Kainer
  1. Hans Ferkel

Published Online: 22 APR 2005

DOI: 10.1002/3527603565.ch58

Magnesium: Proceedings of the 6th International Conference Magnesium Alloys and Their Applications

Magnesium: Proceedings of the 6th International Conference Magnesium Alloys and Their Applications

How to Cite

Ferkel, H. (2005) Creep Properties of Mg Dispersion-Strengthened by Graphite, in Magnesium: Proceedings of the 6th International Conference Magnesium Alloys and Their Applications (ed K. U. Kainer), Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, FRG. doi: 10.1002/3527603565.ch58

Editor Information

  1. GKSS-Forschungszentrum, Institut für Werkstoffforschung, Max-Planck-Straße, 21502 Geesthacht, Germany

Author Information

  1. Institut für Werkstoffkunde und Werkstofftechnik, Technische Universität Clausthal, Agricolastr. 6, 38678 Clausthal-Zellerfeld, Germany.

Publication History

  1. Published Online: 22 APR 2005
  2. Published Print: 27 NOV 2003

ISBN Information

Print ISBN: 9783527309757

Online ISBN: 9783527603565

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Keywords:

  • creep properties;
  • dispersion-strengthened magnesium;
  • graphite

Summary

Mg was dispersion-strengthened by graphite via powder metallurgy. The material was produced by ball milling of Mg micropowder of a median particle diameter of 40 µm with 3 Vol.% of graphite powder with a median particle diameter between 1 and 2 µm. After 8 h of milling the product was consolidated by hot extrusion. Structure analysis reveals that a submicrocrystalline structure developed during milling. Tensile tests show that the material is brittle even up to 300 °C and therefore, most mechanical tests were carried out under compression. Under those condition the reinforced material shows flow stresses of 270 MPa at ambient temperatures, 170 MPa at 150 °C, and 125 MPa at 300 °C whereas Mg processed under the same condition without graphite addition reveals significantly lower yield stresses. The dispersion-strengthened Mg shows a marked increase in the creep resistance: at 200 °C and a stress σcof 100 MPa, the secondary creep rate εs is in the lower 10−9 s−1 range and at 300 °C and σc of 80 MPa, εs values of up to 1 × 10−8 s−1 were measured. The results are discussed.