A study of fracture behaviour of gamma lamella using the notched TiAl micro-cantilever

Research output: Contribution to journalArticle

Authors

  • Rengen Ding
  • Yu-Lung Chiu
  • Mingqiang Chu
  • Sanjooram Paddea
  • Guangqiao Su

Colleges, School and Institutes

Abstract

Microcantilevers were machined from a single γ(TiAl)-α 2(Ti 3Al) lamellae colony of a polycrystalline commercial Ti-45Al-2Mn-2Nb sample using the focussed ion beam. The long axis of the microcantilevers is perpendicular to the lamellar interface with the notch prepared in the same γ lamella. Bending test results demonstrated good repeatability and the fracture stress intensity factor of individual γ lamella was measured to be 3.1 ± 0.2 MPa m 1/2. (Formula presented.) twinning ahead of the notch (crack) tip plays a key role in the crack initiation. TEM analysis shows that the interaction of twinning with the lamellar interface leads to interfacial cracking and contributes to the work-hardening observed.

Details

Original languageEnglish
Pages (from-to) 982-997
Number of pages16
JournalPhilosophical Magazine
Volume100
Issue number8
Publication statusPublished - 16 Jan 2020

Keywords

  • Electron microscopy, FIB, Fracture, Microcantilever, γ-TiAl

ASJC Scopus subject areas