Ab initio reappraisal of the < c plus a > dislocation-associated stacking faults in hcp titanium: a new dissociation mechanism

作者：Liang L; Duparc O B M Hardouin^*

来源：Philosophical Magazine Letters, 2017, 97(1): 19-26.

DOI：10.1080/09500839.2016.1265680

• First-principles
• stacking faults
• &lt
• c plus a &gt
• dislocation dissociation

The < c + a > slip is a secondary slip system in hexagonal close-packed metals which is often activated when they undergo a c-axis deformation. The behaviour of the < c + a > screw dislocation remains unclear. Via ab initio calculations with an all atom all direction relaxation method, we find a stable 0.57 < c + a > stacking fault on {11 (2) over bar2} plane (pi(2)) and a stable nanotwinned -0.215 < 10 (1) over bar2 > stacking fault on {10 (1) over bar1} plane (pi(1)) in alpha-Ti. Based on these results, we propose < c + a > screw dislocation dissociation mechanism which allows a split to three partials. This suggests a more complex < c + a > screw dislocation-related cross-slip mechanism.

• 出版日期2017