Properties of MgO transparent ceramics prepared at low temperature using high sintering activity MgO powders

Transparent MgO ceramics are successful fabricated via spark plasma sintering at lower temperature using the high sintering activity powders synthesized by precipitated method. The samples were detected by XRD, SEM, TEM, BET, UV-Vis-NIR, microhardness, and so on. The results show that all ceramics prepared at 700 degrees C-900 degrees C are visually transparent and the sample sintered at 860 degrees C for 5 min exhibits the superior transmittance of 60% (800 nm). It is also found that the mechanical and thermal properties of MgO ceramics are all increasing firstly and then decreasing with the increase in the sintering temperature. And the maximum value of hardness, fracture toughness, MSP strength, and Young's modulus of MgO ceramics is 8.25 GPa, 2.01 MPa center dot m(1/2), 206 MPa, and 286 GPa, respectively. Moreover, the thermal conductivity of MgO ceramics sintered at 860 degrees C can reach 48.4 W/mK at room temperature.