Inconel/Cu Multimetallic Composites for Space Applications under Radiation

Abstract Additively manufactured Inconel/GRCop-84 is a candidate material for rocket nozzles. In this study, we explored the effects of space radiation on the stability and integrity of representative Inconel/Cu interfaces using atomistic simulations with previously validated interatomic potentials to assess their viability for extraterrestrial applications. We examined the mechanochemistry of the constituent elements and their effects on radiation resistance across two Inconel variants: Inconel 625 (Ni 72 Cr 23 Fe 5 ) and Inconel 718 (Ni 55 Cr 21 Fe 24 ). Our findings reveal three distinct stages—i.e., linear, exponential, and plateau—in the relationship between Frenkel Pair (FP) defect density and radiation damage. FP defect clustering planes were identified on both the Inconel and Cu sides, with Stacking Faults (SF) and Lomer-Cottrell (LC) locks forming on the Inconel side. Moreover, we determined that the orientation of the FP defect clustering planes was influenced by shear stress. We also found that a higher Fe concentration reduces diffusivity between metallic layers, while a higher Cr concentration, owing to its low migration energy barrier, enhances diffusivity.