Preparation and Characterization of Nanostructured Yb2SiO5 Feedstock for Environmental Barrier Coatings

Nanostructured rare earth silicate coatings are considered to be the development direction of new environmental barrier coatings in the future. The thermophysical properties of Yb2SiO5 and the interlayer mullite are well matched and have excellent water and oxygen corrosion resistance. It is considered to be a very promising candidate for environmental barrier coating surface layer. From the perspective of material preparation, explored the preparation process of nano-structured Yb2SiO5 feedstock and characterized its phase, structure and performance. The spray granulation and solid phase sintering method was used to prepare nanostructured Yb2SiO5 sprayed feedstock, and the solid phase sintering process for preparing high-purity Yb2SiO5 was explored, and plasma treatment was used to improve the spraying performance of the feedstock. The phase of the feedstock was studied with the aid of X-ray diffractometer, the morphologies and microstructure of the feedstock were studied by scanning electron microscope and transmission electron microscope, and the fluidity, bulk density, tap density and particle size distributionand of the final feedstock were tested. Results show that the solid-phase sintering process adopts heat preservation at 1500 degrees C for 4 h, and then plasma treatment of the feedstock can obtain high-purity Yb2SiO5 sprayed feedstock. The feedstock after plasma treatment is nano-structured and the particle size distribution of the feedstock meets the requirements of plasma spraying, and the feedstock has good fluidity and compactness.