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

Abstract

In this study, nanostructured and conventional Yb2SiO5 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 Yb2SiO5 coatings have a mono‐modal distribution, and the conventional Yb2SiO5 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 Yb2SiO5 coating were more apparent than those of the conventional Yb2SiO5 coatings. The nanostructured Yb2SiO5 coating had a higher elastic modulus than the conventional Yb2SiO5 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 Yb2SiO5 coatings had improved healing ability and micro‐mechanical properties.

Recent Advances in the Plasma-Assisted Synthesis of Silicon-Based Thin Films and Nanostructures

“…Zheng and coworkers [81] employed an APP plasma spray technique, using a power in a range between 40-44 kW, to achieve the deposition of nanostructured and conventional Yb2SiO5 coatings on SiC substrates, for application as environmental barrier coatings to prevent the oxidation of SiC-based turbines in aeromotive engines. The different film morphologies were achieved using different kinds of precursor powders to be injected into the plasma flow.…”

“…The composition of the graded layer was changed during the deposition, starting with a pure SiAl layer and adding Cu and Fe in increasing quantities as the growth proceeded, with the aim of improving layer adhesion on the Al surface. Zheng and coworkers [81] employed an APP plasma spray technique, using a power in a range between 40-44 kW, to achieve the deposition of nanostructured and conventional Yb 2 SiO 5 coatings on SiC substrates, for application as environmental barrier coatings to prevent the oxidation of SiC-based turbines in aeromotive engines. The different film morphologies were achieved using different kinds of precursor powders to be injected into the plasma flow.…”