In the case of the AP-Zt-HP sample, without glass phase but sintered with a maximum pressure of 80 MPa, the sintering behaviour is similar to AP ng , a sample sintered at 40 MPa with glass phase (FIGURE ). The densification curve shows a pronounced bump, showing better densification than the other samples without glass phase, illustrated by a higher relative density after sintering (99%) (TABLE ). The microstructure is also very similar, with a homogeneous distribution of zirconia particles, a good platelet orientation and no apparent grain growth. Crack deviation is clearly noted and R-curves have an average slope around 20.10 3 MPa.m -0.5 , just like the other samples with tetragonal zirconia particles.