Patent ID: 8114473

Claim:
An aerosol deposition method of producing a composite structure, comprising the steps of: generating an aerosol by mixing a powder comprising yttrium oxide fine particles having a 50%-average particle diameter on volumetric basis of 0.1 to 1.0 μm with a carrier gas; and ejecting the aerosol so that it impacts against a base material surface at a high speed so as to form the composite structure on the base material surface; wherein the base material surface consists of a ceramic polycrystal and has an average surface roughness (Ra) of 100 nm or less; wherein the powder further comprises film formation aiding particles having an average particle diameter larger than the yttrium oxide fine particles so as to deform or crush the yttrium oxide fine particles in the ejecting step; and a Vickers hardness of a surface of the ceramic polycrystal base material is 1,100 Hv or more.