2026-10-13T18:23:56Z https://www.scidb.cn/oai

10.57760/sciencedb.j00125.00174 2026-07-30T16:35:37Z

2026-07-30 Revealing abnormal micro- and meso-structure evolution mechanism of porous pyrolytic carbon in TRISO coated fuel particles under high-temperature treatment doi:10.57760/sciencedb.j00125.00174 en Porous pyrolytic carbon (PPyC) serves as a buffer layer in tri-structural isotropic (TRISO) coated particles for nuclear fuel. However, its unique low-density and porous structure leads to uncertainty in the high-temperature structural evolution behavior. In this study, PPyC was subjected to heat treatment from 1200°C to 1600°C. Results clearly identify 1400°C as the key structure-performance evolution threshold. Below this temperature, structural evolution is dominated by oxygen-defect migration. Above it, transition zones between amorphous and crystalline domains generate abundant vacancies, while grain-boundary pinning restricts atomic motion and increases structural disorder. The combined effects of sintering-neck formation, interlayer shrinkage, and theoretical particle-volume expansion drive the dynamic evolution of the pore structure, leading to a reversible open-to-closed pore transition at the mesoscale. This work systematically clarifies the high-temperature structural evolution mechanism of PPyC, effectively fills the existing gap in low-density pyrolytic carbon evolution theory, and provides valuable theoretical support for the optimal design of TRISO particles and other high-performance novel functional carbon material. TRISO coated fuel particles; Porous pyrolytic carbon; High temperature treatment; Microstructure evolution; Transition zone; Pore evolution 雷锦宏 赵宏生 杨旭 程星 杨辉 于浩 张凯红 刘小雪 刘兵 RESTRICTED dataset Science Data Bank