X-ray Diffraction (XRD) analysis were performed using a D8 advance Diffractometer (Bruker) with a scan speed of 1° min -1 and a step size of 0.01° on unpolished disk surfaces for 2θ angles between 27° and 33° in order to detect the presence of the different phase of zirconia (m : monoclinic and t : tetragonal).