Synthesis mechanism and preparation of LaMgAl11O19 powder for plasma spraying

Lanthanide magnesium hexaaluminate (LaMgAl11O19) powders were successfully synthesized by the solid-state reaction method. The objective of this study was to investigate the synthesis mechanism of LaMgAl11O19 and prepare LaMgAl11O19 powders suitable for plasma spraying. The results show that LaAl11O3 reacts with MgAl2O4 and Al2O3 to form LaMgAl11O19 at approximately 1300 degrees C. Single-phase LaMgAl11O19 powders were prepared successfully by solid-state reaction at a synthesis temperature of 1600 degrees C for 6 h. Unlike the particles in the synthesized powders, those of the centrifugally spray-dried powders have a spherical shape with uniform granularity and good flowability, density, and particle size distribution, making them suitable for plasma spraying. The synthesized powders and centrifugally spray-dried powders remained as a single phase after heat treatment at 1300 degrees C for 100 h, indicating that LaMgAl11O19 has excellent high-temperature stability.