Interatomic potential parameters for Li-Cl-Ti interaction

Conference of the South African Advanced Materials Initiative 2018

Mazibuko, A.F.^1 ; Chauke, H.R.^1 ; Ngoepe, P.E.^1 ; Catlow, C.R.A.^2

Materials Modelling Centre, School of Physical and Mineral Sciences, University of Limpopo, Private bag X1106, Sovenga

0727, South Africa^1

Kathleen Lonsdale Materials Chemistry, Department of Chemistry, University College London, 20 Gordon Street, London

WC1H 0AJ, United Kingdom^2

关键词: Alkali earth metal;    Computational modelling;    Interatomic potential parameters;    Kroll process;    Metallic titanium;    Pair potential;    Titanium materials;    Titanium production;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/430/1/012016/pdf
DOI  :  10.1088/1757-899X/430/1/012016

来源: IOP

【 摘 要 】

Alkali metals and alkali earth metals can be used as reducing agents of titanium halide in titanium production. Despite South Africa's position as being the major raw titanium material producer, titanium production is low and expensive as a direct consequence of the outmoded technology that is used in its extraction from raw materials such as the Kroll process. In this study, computational modelling techniques were employed to simulate the conditions for LiCl that will be suitable for generating a large quantity of metallic titanium in pure and powder form. We used a combination of density functional theory and molecular dynamics, employing FHI-aims, DL-POLY and GULP to characterize LiCl in a solid and molten form. The derived potentials reproduced the LiCl structure to within 1% in agreement with experimental data. More importantly, the melting temperature was deduced from the diffusion coefficient as 800 K which is closer to the experimental melting point of 878 K. Furthermore, the interaction of Ti-Li, Ti-Cl and Li-Cl-Ti were tested and gave reasonable results to set an environment for titanium clusters. The new pair potentials were deduced as Ti-Cl: De = 0.400 a0 = 1.279 r0 = 2.680 and Ti-Li: De = 0.730 a0 = 1.717 r0 = 2.000. The findings of this work will contribute towards the development of alternative ways of titanium production in a continuous and less expensive processes.