Evolution of microstructure and grain boundaries during annealing of high-purity tantalum materials.

The microstructure and texture evolution of tantalum (Ta) during annealing were studied in this work, in addition to simulating and analyzing of the grain boundary motions and their interactions using molecular dynamics simulations (MD). The results showed that the evolution of the recrystallized texture in the surface region of Ta is different from that in the core region. Coincident site lattice (CSL) is significantly related to the grain orientation and thus directly affects the recrystallization texture. MD results showed that the grain boundary mobility rate is higher at low angle grain boundaries (LAGB), which implied that the mobility rate is influenced by the tilt angle. Lower mobility rate of high angle grain boundary (HAGB) possibly caused by a large number of stabilized Σ3 grain boundaries (GBs) between them. It is shown that the inhomogeneous distribution of the recrystallization texture during the annealing process can be possibly attributed to the presence of a large number of Σ3 GBs. • The variation of low-Σ CSL GBs with annealing temperature is similar to the {111} orientation, and the high-Σ CSL GBs change similarly to the {001} orientation. • The formation of {111} texture is mainly controlled by Σ3 and Σ5 GB. • Σ3 GBs of large and stable exist, and even other GBs tend to change towards Σ3 GBs, leading to an increase in the {111} recrystallization texture. [ABSTRACT FROM AUTHOR]