2018 Volume 59 Issue 4 Pages 580-584
Thermal vacancies in solids have not been treated explicitly in the CALPHAD-type thermodynamic assessments because it was considered that their contributions to the Gibbs energy were limited, even at the melting point. However, the vacancy fraction is necessary for dynamic simulations, such as precipitations and diffusion processes. In this paper, a procedure is proposed to set parameters in the CALPHAD-type assessments, to reproduce the temperature dependency of thermal vacancies in pure metals and solid solutions.
This Paper was Originally Published in Japanese in J. Japan Inst. Met. Mater. 81 (2017) 127–132. In order to more precisely explain how to set the Gibbs energy of the empty end-member, the 0GmVa term was explicitly described in eqs. (19) and (20). The reference 8) was changed. Eq. (21) was omitted. Eqs. (4), (5), (21), (22) and (23) were renumbered.
