What controls temperature dependence of yield stress in L12-ordered intermetallic compounds?

Haruyuki Inui, Norihiko L. Okamoto

Research output: Chapter in Book/Report/Conference proceedingConference contribution


The temperature dependence of yield stress and the associated dislocation dissociation in Ll2 intermetallic compounds are investigated in order to check the feasibility of the classification of Ll2 intermetallic compounds so far made in terms of the planarity of core structures of partial dislocations with b = 1/2<110> and 1/3<112> on {111} and {001} glide planes. In contrast to what is believed from the classification, the motion of APB-coupled dislocations is evidenced to give rise to the rapid decrease in yield stress at low temperatures for Pt3Al. In view of the fact that rapid decrease in yield stress at low temperatures is also observed in Co3(Al,W) and C03Ti in which APB-coupled dislocations are responsible for deformation, the SISF-type dissociation is not a prerequisite for the rapidly decreasing CRSS for slip on (111) and the relative magnitudes of the APB energy on (111) and the SISF energy on (111) cannot be a primary factor that determines the type of the temperature dependence of CRSS for Ll2 compounds. The importance of the CSF energy as a factor determining the type of the temperature dependence of yield stress for Ll2 compounds through the changes in the planarity of the core structure of the APB-coupled partial dislocation with bp =1/2[110]is discussed in the light of experimental evidence obtained from Pt3Al.

Original languageEnglish
Title of host publicationAdvanced Structural and Functional Intermetallic-Based Alloys
EditorsI. Baker, M. Heilmaier, K. Kishida, M. Mills, S. Miura
PublisherMaterials Research Society
Number of pages11
ISBN (Electronic)9781510806344
Publication statusPublished - 2015
Externally publishedYes
Event2014 MRS Fall Meeting - Boston, United States
Duration: 2014 Nov 302014 Dec 5

Publication series

NameMaterials Research Society Symposium Proceedings
ISSN (Print)0272-9172


Other2014 MRS Fall Meeting
CountryUnited States

ASJC Scopus subject areas

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

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