The sintering process of ceramics consists of three major stages. In the initial stage, a strong bonding happened between the tangential particles to reduce the Helmholtz's free energy (A) of the surface atoms in constant volume (short time). In the intermediate stage, interparticle neck growth (long time) happens in order to decrease the system's Gibb's free energy (G) at constant pressure where most of the open pores that are connected to the external surface are annihilated. In the final stage the closed pores are eliminated and the monolith became hermetic and grain growth propagate at higher kinetic rates. Intermediate and final state have been vastly