Mixing enthalpy-driven variations in ablation thresholds and laser-induced crater morphologies of CoCuFeNiMnMox (x=0.5, 1.0, 1.5) high-entropy alloys under UV nanosecond laser pulses

Abstract

This study investigates the ablation threshold fluence and power dependence of ablation process in CoCuFeNiMnMox (x = 0.5, 1.0, and 1.5) high-entropy alloys under ultraviolet nanosecond laser pulses. The ablation threshold value, a critical parameter determining the minimum energy density required for laser material removal, is explored in-depth. Mixing enthalpy, characterizing the energy change during the formation of solid solutions, is calculated for the alloys, shedding light on their atomic interactions and phase stability. Laser- induced crater morphologies are analyzed using white light interferometry and optical microscopy, showing distinct features influenced by laser fluence and pulse number. Results demonstrate that an increase in laser pulse energy correlates with an increase in standard deviation. The relationship between crater size, laser pulse energy, and ablation depth is examined, highlighting the alloys' diverse ablation thresholds.