Sintering behavior and technological properties of nano-cubic zirconia/calcium zirconate ceramic composites

Zirconia-calcium zirconate ceramic composites were synthesized and their densification parameters and microhardness were investigated. Zirconium chloride and limestone were mixed in different molar ratios: 1:1 (Z1), 2:1 (Z2), 3:1 (Z3), and 4:1 (Z4) to prepare the composites using the co-precipitation method. The precursors were fired at 900 degrees C for 1 h. The four samples (Z1, Z2, Z3, and Z4) were then shaped and sintered at 1550 degrees C for 2 h. The phase compositions and microstructures of the sintered samples were investigated by X-ray diffraction and scanning electron microscopy. The results indicated that the particle sizes of all the prepared powders were within the nanometric size range (43-67 nm). In addition, the densification parameters [bulk density similar to 4.2 g/cm(3) and apparent porosity (AP) similar to 0.16%] and microhardness (similar to 565.76 HV) of the sintered samples improved with an increase in cubic zirconia content. While the AP of the samples increased with an increase in the calcium zirconate phase fraction.