Numerical simulation of gravity induced skeletal settling during liquid-phase sintering

In this paper we have investigated numerically the phenomenon of gravity induced skeletal settling during liquid-phase sintering, where the solid-skeleton formation was introduced through the definition of skeleton units and their time evolution during the formation of a large solid skeleton. Since it was assumed that under gravity, Stokes’s law settling usually dominates microstructure formation, the settling time was used for computation of the average migration distance during the time interval Δt. Thus gravity induced solid-phase evolution was simulated by means of simultaneous computation of the displacement of the center of mass and mass transport due to dissolution and precipitation at the interfaces between solid-phase domains and the liquid matrix. The new methodology is illustrated by application to a regular multi-domain model including both solid-phase and pore-phase domains. The microstructures computed for tungsten heavy alloy substantiate previous observations that the settled solid-volume fraction can be directly related to the solid–liquid density difference, but is dictated by the formation of a solid skeleton.