Creep properties of Al3Sc and Al3(Sc, X) intermetallics

Y. Harada*, D. C. Dunand

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

55 Scopus citations

Abstract

A systematic creep study was undertaken for the binary intermetallic Al3Sc and the ternary single-phase intermetallic Al3(Sc0.74X0.26), where X is one of the transition-metals Ti, Y, Zr or Hf. Creep tests were conducted in the temperature range from 673 to 1200 K under a constant compressive stress ranging from 30 to 300 MPa. The binary Al3Sc exhibits a stress exponent of 4.4-4.9 indicative of creep controlled by climb of dislocations. The activation energy for creep of Al3Sc was 128 ± 6 kJ/mol, close to that for self-diffusion for pure aluminum, in agreement with the Cu3Au rule, indicating that diffusion on the Al-sublattice is controlling. Ternary Al3(Sc0.74X0.26) exhibits a decrease in creep rate by about one order of magnitude for Zr and Hf and by about two orders of magnitude for Ti and Y. For all ternary alloys, a stress exponent of 3.9-5.5 was observed, indicative of dislocation creep. Activation energies for creep of 202 ± 8 kJ/mol were found, showing that ternary substitution for scandium with transition metals affects diffusion on the Al sublattice.

Original languageEnglish (US)
Pages (from-to)3477-3487
Number of pages11
JournalActa Materialia
Volume48
Issue number13
DOIs
StatePublished - Aug 1 2000

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Polymers and Plastics
  • Metals and Alloys

Fingerprint Dive into the research topics of 'Creep properties of Al<sub>3</sub>Sc and Al<sub>3</sub>(Sc, X) intermetallics'. Together they form a unique fingerprint.

Cite this