Irradiation effects on additively manufactured porous 316H stainless steel: A molecular dynamics study
Year: 2025
Type: article
Abstract: The distinct porous microstructures in additively manufactured stainless steels (AM-SS) may offer enhanced radiation resistance by potentially serving as sinks to absorb and mitigate radiation induced defects. This work uses molecular dynamics simulations to study the impact of pre-existing pore structures on radiation damage in AM 316H-SS fabricated by the laser powder bed fusion process. Employing Fe-Ni-Cr interatomic potential and the composition of AM 316H-SS, the research incorporated a wide range of pore configurations (1 to 30,720 pores) and primary knock-on atom (PKA) energies (5, 10, and 15 keV). The simulations revealed that defect numbers increased significantly with higher pore counts, especially beyond 256 pores, with the 30,720-pore configuration exhibiting the highest defect retention. Notably, the 6-pore configuration exhibited the minimum number of surviving defects likely due to a favorable spatial distribution or geometric alignment of pores, making it the optimal arrangement for enhancing irradiation resistance in porous materials. Furthermore, a comparative study of PKA placement in the simulation box revealed that the location of the PKA (corner vs. center) does not significantly affect defect production across various pore configurations, validating the robustness of the simulation approach and the generalizability of the findings. The study also found correlations between dislocation evolution, pore configuration, and PKA energy, with higher pore densities altering dislocation formation mechanisms. The presence of Shockley and Stair-rod dislocations under high pore numbers indicated the formation of stable dislocation structures and stacking fault tetrahedra. Notably, higher PKA energies resulted in broader and shifted RDF peaks, marking a transition to a more disordered, semi-amorphous state, especially in high pore number configurations. The full width at half maximum analysis revealed a non-linear relationship between pore configuration, PKA energy, and structural damage. These insights into the behavior of porous AM 316H-SS under radiation conditions contribute to the development of improved materials for nuclear applications.
Source: Computational Materials Science
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,290
OpenAlex ID: W4411364647