Physical and mechanical properties of single crystals of Co-Al-W based alloys with L12 single-phase and L12fcc two-phase microstructures

Haruyuki Inui, Katsushi Tanaka, Kyosuke Kishida, Norihiko L. Okamoto, Takashi Oohashi

Research output: Contribution to journalConference articlepeer-review

2 Citations (Scopus)


Single-crystal elastic constants of Co3(Al,W) with the cubic L12 structure have been experimentally measured by resonance ultrasound spectroscopy at liquid helium temperature. The values of all the three independent single-crystal elastic constants and polycrystalline elastic constants of Co3(Al,W) experimentally determined are 15-25% larger than those of Ni3(Al,Ta) but are considerably smaller than those previously reported. Two-phase microstructures with cuboidal L12 precipitates being well aligned parallel to <100> and well faceted parallel to (100) are expected to form very easily in Co-base superalloys because of the large value of E111|E100 and Cij of Co3(Al,W). This is indeed confirmed by experiment. Values of yield stress obtained for both [001] and [123] orientations of L1 2/fcc two-phase single crystals moderately decrease with the increase in temperature up to 800°C and then decrease rapidly with temperature above 800°C without any anomaly in yield stress. Slip on (111) is observed to occur for both orientations in the whole temperature range investigated.

Original languageEnglish
Pages (from-to)369-374
Number of pages6
JournalMaterials Research Society Symposium Proceedings
Publication statusPublished - 2009 Nov 17
Externally publishedYes
Event2008 MRS Fall Meeting - Boston, MA, United States
Duration: 2008 Dec 22008 Dec 5

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering


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