Precipitate strengthening in nanocrystalline Ti/Ta composites

ABSTRACT

Introducing precipitates significantly improves the strength of metallic materials. In the present study, we elucidate the role of a precipitated Ti phase on the deformation mechanism in nanocrystalline Ta through atomistic simulations and transmission electron microscopy characterisation. In particular, the Ti/Ta composites have a high yielding strength and flow stress compared to precipitation-free Ta. Especially, the forward stress in the hard Ti precipitate drives lattice rotation, which then increases further the strength and plasticity of the Ta/Ti composites. Furthermore, a large number of dislocations generated from the Ti precipitate result in a strong back stress in the soft Ta phase, which is consistent with our HRTEM observations.

KEYWORDS:

• Ti/Ta composites
• Ti precipitated phase
• atomistic simulations
• transmission electron microscopy
• back-stress strengthening

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All data included in this study are available upon request by contacting the corresponding author.

Additional information

Funding

The authors would like to deeply appreciate the support from the National Science Fund for Distinguished Young Scholars [grant number 51625404], the Foundation for Innovative Research Groups of the National Natural Science Foundation of China [grant number 51621004], the National Natural Science Foundation of China [grant numbers 11772122, 51871092].