Synthesis and characterization of single-phase X2-Lu2SiO5 nanostructured feedstocks for advanced plasma-sprayed environmental barrier coatings

The objective of this work is to synthesize the single -phase X2-Lu2SiO5 nanostructured feedstocks for plasmasprayed environmental barrier coatings (EBCs). Generally speaking, high-performance feedstocks are a prerequisite for obtaining high-performance coatings. The single -phase X2-Lu2SiO5 nanostructured feedstocks were fabricated by a nanopowder reconstitution method for the first time. The morphology and phase structure of X2Lu(2)SiO(5) nanostructured feedstocks were examined. The physical properties of X2-Lu2SiO5 feedstocks were evaluated. In addition, the thermal conductivity of nanostructured X2-Lu2SiO5 coatings was measured. Results show that the single -phase X2-Lu2SiO5 nanostructured feedstocks are successfully synthesized when the mole ratio of Lu2O3 and SiO2 nanopowder is 1:1.1 and the agglomerated powders are sintered at 1300 C for 2 h. The nanocrystalline size of the X2-Lu2SiO5 feedstocks ranges from 40 to 70 nm. Moreover, the d(10), d(50 )and d(90) of X2Lu(2)SiO(5) feedstocks are 24.69 mu m, 37.78 mu m and 54.75 mu m, respectively. The apparent density and tap density of X2-Lu2SiO5 feedstocks are 1.76 g/cm(3) and 2.09 g/cm(3), respectively. The thermal conductivity of as-deposited Lu2SiO5 coating is 0.78-1.20 W m(-1) K-1 (30-1200 C). Overall, the single -phase X2-Lu2SiO5 nanostructured feedstocks are the most promising feedstocks for advanced EBCs system in the future.