A phase field model for cold sintering of barium titanate

Cold sintering is a promising technique to significantly reduce the temperatures required to manufacture ceramics from above 1000 °C to below 250 °C. This paper examines the mechanisms underpinning the cold sintering of barium titanate, with experimental data used as inputs for a phase field cold sintering model. The activation energy for the cold sintering of barium titanate was determined from the variation of grain size as a function of both sintering time and temperature. This was calculated as 38 kJ/mol, which is 10 times lower than for conventional solid-state sintering. The model was then used to understand the impact of the chemical driving forces and diffusion coefficients on densification. A parametric study using the phase field model provided insights into the effects of particle size, temperature, pressure and activation energy on the cold sintering process, highlighting the critical role of the flux in facilitating mass transport during cold sintering.