Mechanical and thermal properties of LaMgAl11O19

Lanthanum magnesium hexaaluminate (LaMgAl11O19) powders were synthesized successfully at 1300 °C for 4 h by solid-state reaction, and LaMgAl11O19 ceramic was prepared at 1700 °C for 6 h by pressureless sintering. Phase composition, microstructure, mechanical and thermophysical properties of LaMgAl11O19 ceramic were investigated. Results show that the flexural strength and fracture toughness of LaMgAl11O19 ceramic are 353.3 ± 12.5 MPa and 4.60 ± 0.46 MPa m1/2. Youngʹs Modulus and Poisson ratio is 295 GPa and 0.23, respectively. The linear thermal expansion coefficient of LaMgAl11O19 ceramic from 473 K to 1473 K is 9.17 × 10−6/K, and thermal conductivity at 1273 K is 2.55 W/m K.