Zirconium Oxide Powder, Process For Producing The Same, And Material For Thermal Spraying

[0041]As hydrated zirconia, an uncalcined material of KZ-0Y manufactured by KCM Corporation was used. Hydrated zirconia had a BET specific surface area of 175 m2 / g, a LOI of 12.3% and a crystal structure which was the same type as monoclinic zirconium oxide crystal, and a peak profile broader than the peak profile of monoclinic zirconium oxide crystal in an X-ray diffraction pattern (FIG. 1). One kg of the hydrated zirconia was charged into a quartz vessel, and placed in a quartz furnace together with the vessel. A hydrogen chloride gas (manufactured by Tsurumi Soda Co., Ltd., cylinder hydrogen chloride gas, purity 99.9%) was introduced into the furnace tube under the following conditions for 30 minutes.

flow rate: about 5 cm / minutes

temperature: 25° C. (room temperature)

The temperature was elevated at 300° C. / hour and kept at 1100° C. for 30 minutes while introducing a hydrogen chloride gas. Thereafter, a hydrogen chloride gas was replaced by a nitrogen gas, and the temperature wa

[0042]The powder 1 was charged in a dry ball mill [media: nylon coated iron balls (trade name: HighPla ball)], and deagglomerated for 2 hours to obtain a powder 2. The scanning electron micrograph of the powder 2 was shown in FIG. 3. The powder 2 had the same particle shape, D50 and D90 / D10 as those of the powder 1.