The evolution of pellet relative de

The evolution of pellet relative densities at different sintering temperatures (70 to 265 °C) is presented in Figure 4. The relative density is formulated by dividing envelope density over theoretical density. For both particle sizes and transient liquid phases, the densities increase as the sintering temperature increases. In the case of the initial powder, the maximum density was 84% whereas the ball-milled powder was densified up to 89% of the theoretical density. Such density enhancement can be related to increased surface and improved interparticle packing due to the particle size reduction. Moreover, the smaller particles have more energetically active surface, thus enhancing dissolution at the particle-liquid interfaces, therefore filling the pores by precipitation, which leads to higher densification.