Microstructural characterization, mechanical properties and erosion behavior of Y2O3–MgO nanocomposite films by magnetron sputtering

Abstract

The effect of Y2O3: MgO ratio on the microstructures, mechanical properties, and plasma erosion behaviors of Y2O3–MgO (YM) nanocomposite films were investigated. The columnar growth structure of the YM nanocomposite film is disrupted as the MgO content increases, resulting in the refinement of the Y2O3 grains. When the Y2O3: MgO ratio is 40 : 60, the columnar crystal structure of the YM nanocomposite film can be refinement effectively due to thermodynamic incompatibility of Y2O3 and MgO. As a result, YM nanocomposite film is strengthened significantly with the maximum hardness and elastic modulus of 16.78 ± 0.8 GPa and 149.24 ± 4.7 GPa, respectively. X-ray photoelectron spectroscopy revealed few changes in the elemental and chemical compositions of the surface layer after fluorination in the YM nanocomposite film, confirming the chemical stability of the YM nanocomposite samples. The etching depth is ∼48% lower on the YM nanocomposite film (with a MgO content of 60%) than on the commercial Y2O3 film. The findings show that the strengthened YM nanocomposite film is more erosion resistant than the commercial Y2O3 coating.