Sintering analysis of sub-micron-sized nickel powders: Kinetic Monte Carlo simulation verified by FIB–SEM reconstruction

• We address nickel sintering, which has been a durability issue in solid oxide fuel cell systems.
• Quantitative prediction of microstructure evolution over an entire stage of nickel sintering.
• FIB–SEM observations verify that the simulation can accurately model the sintering process.
• Primary mechanism of densification during sintering at the sub-micron scale has been proposed.

Since sintering of sub-micron-sized particles is a critical phenomenon affecting the electrochemical performance and reliability of solid oxide fuel cell systems, a better understanding of this microstructure-related process is of great importance. In this study, we show that kinetic Potts Monte Carlo modeling is capable of quantitatively predicting the three-dimensional (3D) microstructure evolution over an entire stage of nickel sintering at the sub-micron scale. This is achieved through direct comparison of simulation results and 3D microstructural analysis using focused ion beam–scanning electron microscopy. We show that grain boundary diffusion is the dominant mechanism on densification, while surface diffusion has an impact on the coarsening during sub-micron scale sintering, only acting as one of the multiple mechanisms of sintering.