COMPOSITE STRUCTURE

• Main Authors: NISHIMIZU RYOICHI, ASHIZAWA HIROAKI, IWASAWA JUNICHI, HATONO HIRONORI
• Format: Patent
• Language: English
• Published: 20.05.2008
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

[PROBLEMS] To provide a composite structure which comprises a base and a structure made of yttrium oxide formed on the base and having improved mechanical strength. [MEANS FOR SOLVING PROBLEMS] The composite structure comprises a base and a structure made of yttrium oxide formed on a surface of the base. The structure made of yttrium oxide comprises polycrystalline yttrium oxide as the main component. Substantially no grain boundary layers made of a vitreous substance exist at the interface between the crystals constituting the structure and the polycrystalline yttrium oxide has crystal structures comprising a mixture of a cubic system and a monoclinic system. Due to the constitution, the structure made of yttrium oxide formed on a base can have a higher hardness than an yttrium oxide sinter.