Study on the effects of high-energy electron radiation on tin materials in space

To mitigate the risks of performance degradation and equipment failure in spacecraft tin-based solders induced by high-energy electron radiation in deep-space environments, this study systematically investigates the effects of 10 MeV electron irradiation on polycrystalline pure tin. By integrating Geant4 and COMSOL numerical simulations with electron irradiation experiments (conducted for durations of 90, 180, and 300 s), the evolution of energy deposition and temperature rise, as well as their consequent impact on the surface micro-morphology, crystalline structure, and thermodynamic properties of the tin material, were comprehensively analyzed. Simulation results demonstrate a non-linear growth in electron energy deposition within the tin matrix. For irradiation durations exceeding 180 s, accumulated thermal effects cause the central region of the sample to exceed the melting point of tin, resulting in a pronounced temperature gradient. Morphological characterization confirms that as irradiation time increases, the tin surface evolves from initial solid-state thermal erosion and microcracking to localized melting. This eventually progresses to extensive, severe ablation and resolidification-induced agglomeration, accompanied by a sharp increase in surface roughness. X-ray diffraction (XRD) analysis reveals a dynamic competition between internal displacement damage and thermal annealing effects: the process evolves from initial point defect accumulation and lattice distortion (at 90 s) to the loss of long-range order and an amorphization transition (at 180 s). Ultimately, driven by high-temperature thermal effects, recrystallization occurs, accompanied by abnormal grain growth with a prominent (211) preferred orientation (at 300 s). Furthermore, irradiation-induced defects compromise the material’s thermal stability (resulting in a depression of ∼2 °C in the melting point) and trigger significant macroscopic irradiation hardening and elastic stiffening. These findings indicate that under deep-space high-energy electron radiation, tin-based materials are susceptible to multiple risks, including localized overheating, microstructural reconstruction, and the severe degradation of thermo-mechanical properties. This study provides a crucial theoretical and experimental foundation for the radiation-hardened design of solders in aerospace electronic devices.