Dislocation structure, phase stability and yield stress behavior of ultra-high temperature L1 2 intermetallics: Combined first Principles-Peierls-Nabarro approach

Oleg Y. Kontsevoi, Yuri N. Gornostyrev, Arthur J. Freeman

Research output: Contribution to journalConference article

Abstract

We present results of comparative studies of the dislocation properties and the mechanical behavior for a class of intermetallic alloys based on platinum group metals (PGM) which are being developed for ultra-high temperature applications: Ir 3X and Rh 3X (where X = Ti, Zr, Hf, V, Nb, Ta). For the analysis of dislocation structure and mobility, we employ a combined approach based on accurate first-principles calculations of the shear energetics and the modified semi-discrete 2D Peierls-Nabarro model with an ab-initio parametrization of the restoring forces. Based on our analysis of dislocation structure and mobility, we provide predictions of temperature yield stress behavior of PGM-based intermetallics, show that their dislocation properties are closely connected with features of the electronic structure and the L1 2 → D0 19 structural stability, and demonstrate the dramatic difference in dislocation structure and the mechanical behavior between PGM alloys with IVA and VA group elements.

Original languageEnglish
Article numberS2.7
Pages (from-to)511-516
Number of pages6
JournalMaterials Research Society Symposium Proceedings
Volume842
Publication statusPublished - Aug 25 2005
Event2004 MRS Fall Meeting - Boston, MA, United States
Duration: Nov 29 2004Dec 1 2004

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ASJC Scopus subject areas

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

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