Microstructure and nanomechanical properties of plasma‐sprayed nanostructured Yb2SiO5 environmental barrier coatings

Abstract In this study, nanostructured and conventional Yb 2 SiO 5 coatings were prepared by atmospheric plasma. The microstructure and nanomechanical properties of these coatings were compared before and after heat treatment. The results show that the nanostructured Yb 2 SiO 5 coatings have a mono‐modal distribution, and the conventional Yb 2 SiO 5 coatings have a bimodal distribution. Both types of coatings had improved nanomechanical properties after heat treatment. However, the increased elastic modulus and nanohardness of the nanostructured Yb 2 SiO 5 coating were more apparent than those of the conventional Yb 2 SiO 5 coatings. The nanostructured Yb 2 SiO 5 coating had a higher elastic modulus than the conventional Yb 2 SiO 5 coating, reflecting its high density. Subsequently, the microscopic morphology and micromechanical properties of the coatings were analyzed after heat treatment. Defects in the coatings, including pores, and microcracks, were significantly reduced with grain growth after thermal treatment, and the nanostructured Yb 2 SiO 5 coatings had improved healing ability and micro‐mechanical properties.