Comparison between cold sintering and dry pressing of CaCO3 at room temperature by numerical simulations

Numerical models of solid-state and liquid-phase sintering of CaCO3 at room temperature are developed for applied static pressures as high as 280 MPa. Under the applied static pressure of 280 MPa, solid-state sintering (dry pressing) also works at room temperature due to the significant increase in the magnitude of the strain rate caused by dislocation processes occurring within the grains. Under the applied static pressure as low as 10 MPa, solid-state sintering no longer works due to the drop in the magnitude of the strain rate caused by dislocation processes occurring within the grains. On the other hand, liquid-phase sintering (cold sintering) still works under 10 MPa at room temperature due to the significant contribution of densification due to rearrangement in the presence of liquid as well as that due to contact flattening by dissolution and precipitation.