Confirmation of the ω-phase in electron beam welded Ti–5Al–5V–5Mo–3Cr by high-resolution scanning transmission electron microscopy: An initial investigation into its effects on embrittlement

The ω-phase in the fusion zone of electron beam welded Ti–5Al–5V–5Mo–3Cr alloy has been investigated by high-resolution scanning transmission electron microscopy. It was shown that the ω-phase formed trilayer periodicity, having aω and cω lattice parameters of 4.74 ± 0.035 and 2.90 ± 0.022 Å, respectively. Gradual increases in atomic displacement from the β matrix to the center of the ω precipitates as well as distortion of the matrix in the vicinity of ω were also observed.