Microstructure and corrosion resistance of novel rare-earth-zirconia doped Y₂O₃ plasma-sprayed coating

Y₂O₃ coatings are widely applied in semiconductor etching machines to protect the inner walls of aluminum alloys. This study reports the preparation of yttria-based coatings on aluminum alloy substrates using atmospheric laminar plasma spraying (ALPS) methods. In this study, four yttria-based coatings were designed and tested for their thermal performance, plasma etching resistance, and resistance to laser ablation. The rare-earth-zirconia (RE-ZrO₂) doped Y₂O₃ coating exhibited the best thermal insulation performance, with a thermal conductivity of approximately 0.6 W m⁻¹ k⁻¹ at 600 °C. Plasma etching experiments demonstrated that more rare-earth fluorides were generated on the surface of the RE-ZrO₂ doped Y₂O₃ coating, which weakened the plasma energy. Finally, the lowest etching rate was achieved. Laser ablation experiments demonstrated that the depth of the ablation pit on the surface of the RE-ZrO₂ doped Y₂O₃ coating was shallow, indicating good laser ablation resistance. These results indicate that rare-earth-doped yttria-based coatings provide excellent corrosion protection against plasma etching and laser ablation.