Powder for film formation or sintering
A powder for coating or sintering exhibits a peak assigned to orthorhombic YAlO 3 in an X-ray diffractometry. Of peaks exhibited in the X-ray diffractometry, the peak assigned to the (112) plane of orthorhombic YAlO 3 is a peak that has the highest peak intensity. Preferably, the value of the ratio of S2 to S1, S2/S1, is less than 1 in an X-ray diffractometry using CuKα radiation, where SI represents the peak intensity of the peak assigned to the (112) plane of orthorhombic YAlO 3 and S2 represents the peak intensity of the peak assigned to the (104) plane of trigonal Al 2 O 3 .
1. A powder for coating or sintering,
wherein, in an X-ray diffractometry of the powder, a peak assigned to orthorhombic YAlO 3 , and a peak assigned to cubic Y 3 Al 5 O 12 or monoclinic Y 4 Al 2 O 9 are exhibited,
of peaks exhibited in the X-ray diffractometry, a peak assigned to a (112) plane of orthorhombic YAlO 3 is a peak that has the highest peak intensity,
in an X-ray diffractometry using CuKα radiation, a value of a ratio of S3 to S1, S3/S1, and a value of a ratio of S4 to S1, S4/S1, are each independently less than 1, where S 1 represents a peak intensity of a peak assigned to a (112) plane of orthorhombic YAlO 3 , S3 represents a peak intensity of a peak assigned to a (420) plane of cubic Y 3 Al 5 O 12 , and S4 represents a peak intensity of a peak assigned to a (−221) plane of monoclinic Y 4 Al 2 O 9 , and
in a pore volume distribution relative to pore sizes as measured by mercury intrusion porosimetry, the powder exhibits at least one peak in each of a range of pore sizes from 0.1 to 1 μm and a range of pore sizes from 5 to 50 μm, a volume of pores with a pore size from 0.1 to 1 μm is 0.1 mL/g or greater, and a volume of pores with a pore size from 5 to 50 μm is 0.1 mL/g or greater.
2. The powder for coating or sintering according to claim 1 ,
wherein, in the X-ray diffractometry of the powder, no peak assigned to trigonal Al 2 O 3 is exhibited, or if a peak assigned to trigonal Al 2 O 3 is exhibited, a value of a ratio of S2 to S1, S2/S1, is less than 1 in an X-ray diffractometry using CuKα radiation, where S1 represents a peak intensity of a peak assigned to a (112) plane of orthorhombic YAlO 3 and S2 represents a peak intensity of a peak assigned to a (104) plane of trigonal Al 2 O 3 .
3. The powder for coating or sintering according to claim 1 ,
wherein, in the X-ray diffractometry of the powder, no peak assigned to cubic Y 2 O 3 is exhibited, or if a peak assigned to cubic Y 2 O 3 is exhibited, a value of a ratio of S5 to S1, S5/S1, is 1 or less in an X-ray diffractometry using CuKα radiation, where S1 represents a peak intensity of a peak assigned to a (112) plane of orthorhombic YAlO 3 , and S5 represents a peak intensity of a peak assigned to a (222) plane of cubic Y 2 O 3 .
4. The powder for coating or sintering according to claim 1 , having a crystallite size of 50 nm or greater as determined from a full width at half maximum of the peak assigned to a (112) plane of orthorhombic YAlO 3 in the X-ray diffractometry of the powder.
5. The powder for coating or sintering according to claim 1 , having a BET specific surface area of 1 to 5 m 2 /g.
6. The powder for coating or sintering according to claim 1 , wherein the powder is granular and has an average particle size of 15 μm or greater.
7. A method for producing a coating, comprising forming a coating of the powder for coating or sintering according to claim 1 by thermal spraying or PVD.