Characterizing the interactions of edge dislocation dipole in hexagonal close packed Ti-Al alloys

• Published in: Materials & design 2019-02, Vol.164, p.107559, Article 107559
• Main Authors: Wu, Hao, Leng, Jinfeng, Teng, Xinying, Su, Tao, Li, Qinggang, Li, Jinkai, Wu, Junyan, Xu, Daokui, Zhu, Yongchang
• Format: Article
• Language: English
• Subjects: Crystal defects; High-resolution electron microscopy (HREM); Homogenization/solutionization; Strengthening; Titanium alloys
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2018.107559

The aim of the present work is to elucidate the interaction between dislocation dipoles decorated by trace addition of solute atoms in the model material of as-annealed coarse-grained Ti-3Al (weight percent, wt%) alloys. The morphology, activity, structure, strain field, and interaction of dislocation cores were systematically characterized. Theoretical predictions of equilibrium distribution of edge dislocation dipoles presenting an angle of 45° relative to each other were experimentally demonstrated. More importantly, we observed for the first time the 45°-rotating of strain fields around the dislocation core along a clockwise direction for stress equilibrium which is driven by the dislocation-dislocation interactions. [Display omitted] •The interaction between edge dislocation dipoles was elucidated.•Theoretical predictions of equilibrium distribution of edge dislocation dipoles were demonstrated.•The 45°-rotating of strain fields around the dislocation core was observed for the first time.