Temperature-driven cavitation lead–bismuth eutectic coolants: Linking shock-wave-induced collapse dynamics to macroscopic damage

Systematic understanding of the temperature-dependent cavitation damage correlation in liquid lead–bismuth eutectic (LBE) remains limited. As lead–bismuth-cooled nuclear reactors are critical to energy systems, and cavitation poses significant safety risks, understanding LBE cavitation behavior and its damage mechanisms is essential. This study examines cavitation behavior in LBE and its damage mechanisms by combining molecular dynamics (MD) simulations with ultrasonic cavitation experiments. MD simulations modeled shock-induced bubble collapse near an iron wall at temperatures of 410, 430, and 450 K, analyzing pressure, velocity, temperature fields, and atomic displacement. Experiments characterized surface erosion and hardness of 316L stainless steel. Results reveal a decisive and non-monotonic temperature influence on cavitation dynamics. While 430 K represents the peak of hydrodynamic intensity (generating a maximum collapse pressure of 55.06 GPa), the most severe macroscopic cumulative damage occurs at 450 K. This divergence demonstrates that material thermal softening dominates over fluid aggressivity at higher temperatures. Furthermore, double-bubbles simulations indicate that synchronous collapse and uniform energy transfer significantly amplify wall erosion compared to single-bubble events. These insights clarify the temperature-dependent damage mechanism in LBE and provide critical support for the design of LBE-cooled reactor components.