The effect of microstructural characteristics on fracture behaviour mechanism for electron beam welding of Ti–6Al–4V was investigated. The results indicated that the welded microstructure composed of coarse needle 𝛼 + 𝛽 phases presenting disordered and multidirectional short needle morphology to make fracture mechanism complex. The coarse grains in weld seam with microhardness 536 HV were easy to be fractured in the region where welding heat input was ≥ 68.8 kJ/m. There exists flat curves of Ti, Al and V, Fe concentration distribution fluctuation to cause microstructural amplitude-modulated decomposition to increase the joint ductility and cleavage strength. The uneven distribution of the partial micropores located at the interior of the specimen acting as crack initiation sites lead to non-linear branch propagating path. The 𝛼 + 𝛽 interlaced structure results in the fracture location near 𝛼/𝛽 interface. The existence of stacking fault structure caused pile-up of dislocation to produce micropores to be new fracture initiation sites.
Volume 45, 2022
Continuous Article Publishing mode
Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020
Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
Physical Sciences 2020
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