Effects of boron addition on microstructure and mechanical properties of an Ir85Hf15 two-phase refractory superalloy

Y. F. Gu, Y. Yamabe-Mitarai, T. Yokokawa, H. Harada

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


The aim of this study is to understand the effects of boron addition on the mechanical properties of the Ir85Hf15 two-phase refractory superalloy, especially on the fracture behaviour and the high-temperature strength. Our results indicated that adding boron was an effective way to raise the strength of Ir85Hf15 alloy at both room and high temperatures when the boron content was below a limited value, which was approximately 200 wppm for Ir85Hf15 alloy. Meanwhile, adding boron did not significantly improve the ductility, but it changed the fracture mode from the morphology of grain-boundary fractures generally observed in polycrystalline Ir and binary Ir85Hf15 alloys to mainly transgranular cleavage seen in the boron-doped Ir85Hf15. The effects of boron addition are discussed in terms of microstructure change and phase constitution.

Original languageEnglish
Pages (from-to)1171-1178
Number of pages8
JournalMaterials Letters
Issue number5-6
Publication statusPublished - 2003 Jan
Externally publishedYes


  • Boron addition
  • Ir-Hf alloy
  • Mechanical properties
  • Microstructure

ASJC Scopus subject areas

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

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