Yttrium-based sprayed coating and making method
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsYasushi Takai, Noriaki Hamaya
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Abstract
An yttrium-base sprayed coating is obtained by thermally spraying yttrium oxide, yttrium fluoride or yttrium oxyfluoride onto a substrate to form a coating of 10-500 μm thick, and chemically cleaning the coating with a cleaning liquid of organic acid, inorganic acid or a mixture thereof until the population of particles with a size of up to 300 nm becomes no more than 5 particles/mm2 of the coating surface. The yttrium-base sprayed coating exhibits high corrosion resistance even in a halogen gas plasma atmosphere and prevents yttrium-base particles from spalling off during etching treatment.
Claims4
A method for preparing a yttrium-base sprayed coating, comprising the steps of:
- thermally spraying a particulate spray material comprising at least one compound selected from the group consisting of yttrium oxide, yttrium fluoride, and yttrium oxyfluoride to form a yttrium-base sprayed coating having a thickness of 10 to 500 μm and
- chemically cleaning a surface of the coating with a cleaning liquid which is an organic acid aqueous solution, inorganic acid aqueous solution or organic acid/inorganic acid aqueous solution until a population of particles with a size of up to 300 nm is no more than 5 particles per square millimeters of the coating surface.
Dependencies are inferred from the claim text.