Temperature-Dependent Interface-Mediated Deformation and Kinetic-Energy Redistribution in FeNiCrCo-Coated Aluminum

Molecular dynamics simulations were performed to examine the temperature-dependent nanoindentation response of aluminum substrates coated with amorphous or crystalline equiatomic FeNiCrCo layers. The study extends our previous 300 K baseline analysis of the same model system by comparing deformation at 300 and 600 K and by examining the spatial redistribution of local kinetic energy and local nonequilibrium kinetic-temperature indicators during loading and unloading. A spherical virtual indenter with a radius of 30 Å was driven to maximum penetration depths of 35 and 65 Å, representing predominantly coating-controlled deformation and a regime involving the coating–substrate interface and aluminum substrate, respectively. At both temperatures, the crystalline coating exhibited higher indentation resistance and serrated force–depth responses associated with intermittent lattice-mediated plasticity, whereas the amorphous coating showed lower force levels and smoother deformation through distributed local atomic rearrangements. Increasing the temperature from 300 to 600 K enlarged the deformation-affected region and promoted a greater involvement of the interface and Al substrate. Nevertheless, the spatial character of the response remained structure-dependent: the crystalline coating retained a comparatively compact region of elevated local kinetic energy beneath the indenter, whereas the amorphous coating displayed a broader and more diffuse kinetic-energy perturbation. Adaptive common-neighbor analysis was used as a qualitative local-environment descriptor; therefore, structural labels are interpreted together with force–depth curves and atomistic configurations rather than as unique phase identifiers. The results identify temperature-dependent trends in deformation localization and energy redistribution for an idealized FeNiCrCo/Al model system. Because the simulations employ a finite periodic cell, a high indentation velocity, and an empirical potential, the findings are interpreted as qualitative atomistic trends and are not quantitatively extrapolated to experimental indentation conditions.