Fig. 7 displays the microstructures

Fig. 7 displays the microstructures by FE-SEM of green bodies from DT51 and G5 powders, CS_D0 (Fig. 7a) and CS_G0 (Fig.7c), and CSP samples CS_D1 (Fig.7b) and CS_G1(Fig. 7d). In the case of DT51, the microstructure didn’t change after CSP, while in the case of G5 the porous green bodies, made of nanopowder agglomerates, changed in flat fracture surfaces showing a diffused nanoporosity within TiO2 grains. After the thermal treatment of post annealing at 500℃ for 2 h,accordingly with the dilatometric shrinkage and improved sample density, the microstructure appeared more compact (Fig. 7e).