Modeling Dislocation in Binary Magnesium-Based Alloys Using Atomistic Method
In the wake of developing biodegradable metallic implants for orthopedic practice or lightweight structural components for the automotive industry, both fundamental and applied research on magnesium and its alloys regained a high interest in the last decade. As of today, the major issues delaying the integration of the magnesium technology in the medical and automotive industries are (i) a lack of ductility and (ii) a poor corrosion resistance. Alloying is a common strategy used to improve the ductility and the corrosion resistance. Although density functional theory is a powerful method that allows one to quantify material parameters to be used later in a theoretical model, atomistic methods in the framework of semi-empirical potentials are complementary to density functional theory. While the data obtained from semi-empirical potentials are more qualitative than quantitative, it does not prevent atomistic calculations in the framework of semi-empirical potentials to validate/disprove/enrich an existing theoretical model or even to provide insights for the development of a new theoretical model. The validity of the data derived from atomistic calculations in the framework of semi-empirical potentials depends on the accuracy and transferability of the potentials to capture the physics involved in the problem. In view of modeling the mechanical properties of a binary magnesium-based alloy using semi-empirical potentials, one has to validate the ability of the potentials to capture the physics governing the interactions between the alloying element and the micromechanisms carrying the inelastic behavior. In this chapter, we are reviewing the interaction between alloying elements and (i) stacking faults and (ii) <a> dislocations from the basal and prismatic slip systems.
The author acknowledges the MIRACLE Project at the University of Basel funded by the Werner Siemens Foundation, Zug/Switzerland.
- 2.Friedrich HE, Mordike BL. Magnesium technology: metallurgy, design data, application. Berlin: Springer; 2006.Google Scholar
- 8.Kim Y-M, Kim NJ, Lee B-J. Atomistic modeling of pure Mg and Mg-Al systems. CALPHAD Comp Coupl Phase Diagrams Thermo. 2009;33:650–7.Google Scholar
- 19.Kim K-H., Jeon JB., Kim NJ., Lee B-J. Role of yttrium in activation of <c+a> slip in magnesium: an atomistic approach. Scr Mater 2015; 108:104–8.Google Scholar
- 20.Nahhas MK, Groh S. Atomistic modeling of grain boundary behavior under shear conditions in magnesium and magnesium-based binary alloys. J Phys Chem Solids. 2018;113:108–18.Google Scholar
- 24.Karewar S, Gupta N, Groh S, Martinez E, Caro A. Srinivasan S.G. Effect of Li on the deformation mechanisms of nanocrystalline hexagonal close packed magnesium. Comp Mater Sci. 2017;126:252–64.Google Scholar
- 29.Kim K-H, Jeon JB, Lee B-J. Modified embedded-atom method interatomic potentials for Mg-X (X = Y, Sn, Ca) binary systems. CALPHAD Comp Coupl Phase Diagrams Thermo. 2015;48:27–34.Google Scholar
- 33.Tsuru T, Udagawa Y, Yamaguchi M, Itakura M, Kaburaki H, Kaji Y. Solution softening in magnesium alloys: the effect of solid solutions on the dislocation core structure and nonbasal slip. J Phys Condens Matter. 2013;24:02202.Google Scholar
- 40.Zu G., Groh S. Effect of segregated alloying element on the intrinsic fracture behavior of Mg. Theo Appl Frac Mech. 2016;85:236–45.Google Scholar