Mechanical properties and thermal shock resistance of BaAl2Si2O8/BN ceramic composites

BaAl 2 Si 2 O 8 /BN (BAS/BN) ceramic composites were prepared using hot press sintering. The amorphous state of BAS ceramics exhibits a low melting point, high liquid-phase mobility, and good infiltration with BN grains, facilitating the sintering process. Conversely, the crystalline state of BAS has a high melting point and strength, contributing to the strengthening and toughening of the composite. The mechanical properties, thermal properties and thermal shock resistance of BAS/BN ceramic composite was investigated. Ceramic composites containing 40 vol% BAS have the best overall mechanical properties with bending strength, elastic modulus, fracture toughness, and hardness of 175 +/- 3 MPa, 114.0 +/- 1.2 GPa, 2.02 +/- 0.10 MPa & sdot;m 1/2 , and 1.08 +/- 0.01 GPa, respectively. The BAS/BN ceramic composite has excellent thermal shock resistance, and the residual bending strength shows a pattern of increasing and then decreasing with increasing thermal shock temperature difference. Finite element calculation results show that the cooling process is basically completed after 20 s of water quenching, the maximum thermal stress generated is about 22 MPa.