The mechanism of aqueous stress-corrosion cracking of α + β titanium alloys

Sheng Cao, Suming Zhu, Chao Voon Samuel Lim, Xigen Zhou, Xiaobo Chen, Bruce R. W. Hinton, Rodney R. Boyer, James C. Williams, Xinhua Wu

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15 Citations (Scopus)

Abstract

In a previous paper (Cao et al., 2017) [1], a transition in fracture mode in aqueous NaCl Stress-Corrosion Cracking (SCC) of Ti-8Al-1Mo–1 V was reported. This paper attempts to unravel the operating mechanism for SCC by dislocation analysis on the Focus Ion Beam (FIB) lift-out foils from pre-crack and the SCC regions. It is shown that both basal <a> and <c + a> slips are operative in the SCC region while the basal <a> is the only activated system in the pre-crack region. Moreover, there is an increase in dislocation density in the SCC region compared to the pre-crack region. Based on these observations, combined Absorption Induced Dislocation Emission (AIDE) and Hydrogen Enhanced Localized Plasticity (HELP) is proposed to be the operating mechanisms for SCC in α+β titanium alloys.

Original languageEnglish
Pages (from-to)29-39
Number of pages11
JournalCorrosion Science
Volume125
DOIs
Publication statusPublished - 15 Aug 2017

Keywords

  • A. Titanium
  • B. SEM
  • B. TEM
  • C. Hydrogen embrittlement
  • C. Stress corrosion

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