Properties of the Zirconia-leucite Composites
The dental zirconia-leucite composites were synthesized by high temperature solid-state method using potassium feldspar,potassium carbonate and zirconium oxide as raw materials.All the samples were analyzed by using scanning electron microscope(SEM),X-ray diffractometer(XRD),Raman spectrometer,and Energy dispersive X-ray spectrometer(EDX).The mechanical properties and the coefficient of thermal expansion of the samples were also measured.The average bending strength,the fracture toughness and the metal-ceramic bonding strength of the samples were 110 MPa,3.5MPa/m~(1/2) and 45MPa,respectively.The results also indicate that zirconium oxide and leucite in the samples are not only beneficial to the mechanical properties but also favorable to the expansion coefficient of the ceramic material(～13.73×10~(-6)/K) to match with that of the Ni-Cr dental alloy.The increase of the metal-ceramic bonding strength is resulted from the formation of the diffusion-type and combination-type interfaces due to the mutual diffusion of elements in the metal-ceramic interfaces.