Effect of Sintering Temperature on the Properties of Calcia-Stabilized Zirconia (Ca-SZ) Bioceramics

Abstract

This paper highlights the study on effect of sintering temperature on the morphologies and compressive strength of zirconia ceramics doped with calcium oxide (CaO) as stabiliser to enhance the zirconia structure undergo sudden phase transformation. CaO reportedly has good stability in cubic phase at all temperature, which open up a new possibility for new material to evolve for zirconia ceramic dental application. CaO synthesis from calcium nitrate tetrahydrate (Ca(NO3)2.4H2O) is used as metal precursor to produce Calcia-Sabilized Zirconia (Ca-SZ). 8 wt. % of Ca(NO3)2.4H2O and 92 wt. % of zirconium oxide (ZrO2) mixed and stirred together with ethanol as solvent and sintered at temperatures 1200, 1300 and 1400°C. Surface morphologies are investigated by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX) element analysis, X-ray Diffraction (XRD) for composition studies, as well as compressive strength to figure out the mechanical properties of Ca-SZ sample. Increment in sintering temperature enhance the surface morphologies, the phase of Ca-SZ become intensified and transformed from monoclinic to tetragonal ZrO2 also flexural strength increases as well. The compressive strength recorded the highest value of 4537 MPa for Ca-SZ at temperature of 1400°C. The optimal temperature of Ca-SZ suitable for dental application was 1400°C due to the good morphologies and mechanical properties suitable for teeth restoration. The development of Ca-SZ can establish a pathway as an alternative material for dental applications.