Design the alloying elements to positively utilize the oxygen increase during additive manufacturing of steels by molecular dynamics simulations

This study addresses the issue of oxide inclusions in raw metal powders for additive manufacturing affecting component performance, systematically investigating the influence of different oxides on the heterogeneous nucleation of Fe atoms in molten steel. A multi-scale simulation approach was employed: molecular dynamics simulations were used to model the aggregation process of oxide clusters, while ab initio molecular dynamics simulations were applied to study the ordering behavior of Fe atoms on oxide surfaces. By analyzing and comparing the nucleation-promoting capabilities of MgO, Al 2 O 3 , ZrO 2 , CaO, TiO 2 , and La 2 O 3 , TiO 2 was identified as the most beneficial nucleation core with exceptional grain refinement potential. Based on this, an integrated three-dimensional evaluation system for nucleating agents was proposed, incorporating cluster size, lattice mismatch, and atomic ordering capability. This research provides a theoretical foundation for optimizing powder feedstock design in additive manufacturing and transforming oxide inclusions from detrimental to beneficial.