%0 Journal Article %T Effect of CaO on the Formation of PSZ and γ-Zirconia Nanoparticles through Ball Milling %J Advanced Ceramics Progress %I Materials and Energy Research Center (MERC) Iranian Ceramic Society (ICERS) %Z 2423-7477 %A Golzar Shahri, Mohsen %A Shafyei, A. %A Saidi, A. %A Abtahi, K. %D 2015 %\ 06/01/2015 %V 1 %N 2 %P 40-44 %! Effect of CaO on the Formation of PSZ and γ-Zirconia Nanoparticles through Ball Milling %K Ball milling %K Zirconia nanoparticles %K Phase transformation phase stability %K DSC analysis %R 10.30501/acp.2015.90747 %X The effect of CaO on the formation of β- and γ-zirconia nanoparticles from α-zirconia was investigated and their stability evaluated via mechanical activation. α-ZrO2+8.5wt%CaO powder was milled for 2-150 hours with ball-to-powder weight ratios (BPWR) of 40:1 and 60:1. Structural evaluations were conducted using X-Ray diffraction and scanning electron microscope (SEM). Thermal analysis was carried out using Differential Scanning Calorimetry (DSC). Results showed that, γ-zirconia (with a cubic structure) was obtained by ball milling of α-ZrO2+8.5wt%CaO at room temperature. It was found that α to γ phase transformation began after two hours of milling and completed after 48 hours with a BPWR of 40:1. Moreover, the Williamson-Hall equation indicated that the particle size of α-ZrO2+8.5wt%CaO was reduced to 50 nanometers and reached its equilibrium point after 24 hours of milling and was unchanged after that. In addition, DSC analysis showed that β-zirconia and γ-zirconia were unstable in pure ZrO2 powder, while CaO addition led to the stabilization of ZrO2 as β-zirconia and γ-zirconia after ball milling. %U https://www.acerp.ir/article_90747_f16e81e7d0a7f766074f629e58dcdd4f.pdf