The mechanism of aqueous stress-corrosion cracking of alpha plus beta titanium alloys

作者：Cao Sheng^*; Zhu Suming; Lim Chao Voon Samuel; Zhou Xigen; Chen Xiaobo; Hinton Bruce R W; Boyer Rodney R; Williams James C; Wu Xinhua

来源：Corrosion Science, 2017, 125: 29-39.

DOI：10.1016/j.corsci.2017.05.025

• Titanium
• SEM
• TEM
• Stress corrosion
• Hydrogen embrittlement

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 alpha + beta titanium alloys.

• 出版日期2017-8-15