Mechanical and thermal physical properties of amorphous SiCN(O) ceramic bulks prepared by hot-press sintering

Abstract The amorphous SiCN(O) ceramic bulks with a diameter of 50 mm are first prepared using hot-press sintering technology. With an increase in sintering temperatures, the mechanical properties of the SiCN(O) ceramic are improved. After being hot-press sintered at 1500 °C in Ar, the dense amorphous SiCN(O) ceramic is obtained. The values of density, bending strength, fracture toughness and elastic modulus for SiCN(O) ceramic are 2.15 g/cm3, 138.1 MPa, 2.32 MPa·m1/2 and 65.8 GPa, respectively. The carbon precipitation is responsible for the low elastic modulus. Coefficient of thermal expansion of amorphous SiCN(O) ceramic bulks is as lower as 2.69 × 10− 6/K.