JPWO2013176058A1 - Cermet powder - Google Patents

Abstract

The powder product of the present invention is a powder product containing composite particles of ceramics and metal, and at least a part of the composite particles is 10 mN or more as a maximum value at a load speed of 15.0 mN / s or less. In the stress-strain diagram obtained when a compressive load increasing to the size of is given, no break point is shown.

Description

  The present invention relates to a cermet powder material containing composite particles of ceramics and metal.

  Cermet particles, which are composite particles of ceramics and metal, are used in various applications, for example, as described in Patent Document 1, used as a material for forming a thermal spray coating, that is, as a powder for thermal spraying. One of the performances required for the thermal spraying powder is that most of the thermal spraying toward the base material adheres and deposits on the base material to form a film, that is, the adhesive efficiency is high. However, cermet particles are generally difficult to spray with high deposition efficiency compared to metal particles. This tendency is particularly noticeable in the case of low temperature spray processes such as cold spray because the degree of melting and softening of the metal is reduced.

JP2012-12686A

  Therefore, an object of the present invention is to provide a cermet powder material having improved adhesion efficiency when used as a thermal spraying powder.

  In order to achieve the above object, according to one aspect of the present invention, a powder product including composite particles of ceramics and metal, wherein at least a part of the composite particles is 15.0 mN / s or less. There is provided a powder material characterized in that no breaking point is shown in a stress-strain diagram obtained when a compressive load increasing to a maximum value of 10 mN or more is applied as a maximum value at a loading speed.

  In another aspect of the present invention, there is provided a method for forming a thermal spray coating comprising spraying the powder according to the above aspect at a thermal spraying temperature of 3,000 ° C. or lower.

  ADVANTAGE OF THE INVENTION According to this invention, the cermet powder substance which improved the adhesion efficiency when it uses as a thermal spraying powder can be provided.

Stress-strain diagram of two granulated-sintered cermet particles showing different stress-strain behavior. (A) And (b) is a cross-sectional photograph of granulated-sintered cermet particles of the powdered product of Example 2. (A) And (b) is a cross-sectional photograph of granulated-sintered cermet particles of the powdered product of Comparative Example 2.

  Hereinafter, an embodiment of the present invention will be described. In addition, this invention is not limited to the following embodiment, A design change is possible suitably to such an extent that the content of invention is not impaired.

  The powder material of this embodiment consists of granulated-sintered cermet particles. The granulated-sintered cermet particles are a composite of ceramic fine particles and metal fine particles, and are produced by sintering a granulated product (granules) obtained by granulating a mixture of ceramic fine particles and metal fine particles.

  The powder material of this embodiment is used as, for example, a thermal spraying powder. That is, it is used, for example, in applications where a thermal spray coating is formed on a base material by spraying toward the base material.

  In order to obtain high adhesion efficiency when the powder material of this embodiment is used as a thermal spraying powder, at least a part of the granulated-sintered cermet particles is 15.0 mN / s or less, preferably 14 0.0 mN / s or less, most preferably 13.0 mN / s or less, and a maximum value of 10 mN or more, preferably 100 mN or more, more preferably 200 mN or more, still more preferably 500 mN or more, most preferably 900 mN or more. It is necessary not to show the breaking point in the stress-strain diagram obtained when a compressive load increasing to is given.

  A loading speed of 15.0 mN / s or less is a sufficient speed to deform the granulated-sintered cermet particles. The smaller the load speed when applying a compressive load to the granulated-sintered cermet particles, the more accurately the disintegration property of the granulated-sintered cermet particles during the thermal spraying process can be evaluated.

The compressive load of 10 mN or more is large enough to deform the granulated-sintered cermet particles. It is preferable that the maximum value of the compressive load applied to the granulated-sintered cermet particles is larger because the disintegration property of the granulated-sintered cermet particles during the thermal spraying process can be accurately evaluated.
The disintegration property of the granulated-sintered cermet particles means the ease of disintegration of the granulated-sintered cermet particles, the behavior after the disintegration, and the like. By evaluating and controlling the disintegration of granulated-sintered cermet particles, spitting (the deposit formed by depositing the overmelted thermal spraying powder on the inner wall of the nozzle of the thermal sprayer is spraying the thermal spraying powder. This is a phenomenon that drops from the inner wall and mixes into the sprayed coating, which is a factor that degrades the performance of the sprayed coating.) And the problem of reduced hardness of the sprayed coating.

  Stress obtained when compressive load increasing to a maximum value of 10 mN or more at a load speed of 15.0 mN / s or less is applied to two granulated-sintered cermet particles exhibiting different stress-strain behavior A strain diagram is shown in FIG. In FIG. 1, the line with the symbol A shows a behavior having a breaking point where the strain rapidly increases at a certain stress, while the line with a symbol B shows a behavior without such a breaking point. . Of the granulated-sintered cermet particles in the powder according to the present embodiment, the ratio of the granulated-sintered cermet particles exhibiting the stress-strain behavior as shown in FIG. It is preferably 1% or more, more preferably 5% or more, and further preferably 10% or more. All or almost all (for example, about 90%) of granulated-sintered cermet particles may exhibit stress-strain behavior as shown in FIG.

  The ratio of the granulated-sintered cermet particles not showing the breaking point can be determined, for example, as follows. That is, for a plurality of granulated-sintered cermet particles whose particle diameter is arbitrarily selected from powders, the maximum value is increased to 10 mN or more at a load speed of 15.0 mN / s or less. Measure the stress-strain behavior when a compressive load is applied. Then, the proportion of the granulated-sintered cermet particles that did not show a breaking point is calculated. For example, a micro compression tester (MCTE-500 manufactured by Shimadzu Corporation) can be used to measure the stress-strain behavior, but the present invention is not limited to this.

  The granulated-sintered cermet particles that show the stress-strain behavior as shown in FIG. 1 with the line labeled A may break when collided with the substrate when sprayed toward the substrate. The resulting debris may rebound without adhering to the substrate. On the other hand, the granulated-sintered cermet particles exhibiting the stress-strain behavior as shown in FIG. 1 by the line with the symbol B are plastically deformed without breaking when colliding with the substrate. There is a high possibility of adhering to. As shown in FIG. 9 of Japanese Patent Application Laid-Open No. 2011-208165 disclosing the metal material for thermal spraying, the metal particles generally exhibit a stress-strain behavior having no breaking point, and are denoted by the symbol B. It can be said that the stress-strain behavior shown in FIG. Therefore, although the powder material of this embodiment is composed of cermet particles, it is considered that high adhesion efficiency can be obtained when used as a thermal spraying powder.

  As a means for obtaining granulated-sintered cermet particles that do not exhibit the breaking point as described above, it is effective to reduce the size of the metal particle portion in the granulated-sintered cermet particles as much as possible. Specifically, the average diameter (constant direction average diameter) of the metal particle portion is preferably 3 μm or less, more preferably 1 μm or less, still more preferably 0.5 μm or less, and particularly preferably 0.1 μm or less.

  The metal particle part in the granulated-sintered cermet particles plays a role as a binder for bonding the ceramic particle parts in the same granulated-sintered cermet particles, but the granulated-sintered cermet particles have a compressive load. , The granulated-sintered cermet particles may break due to cracks occurring at the bonding sites between the ceramic particle portions. In this regard, as the average diameter of the metal particle portion becomes smaller, the size of the bonding site between the ceramic particle portions becomes smaller, and as a result, the granulated-sintered cermet particle breaks due to the occurrence of cracks in the bonding site. Can be suppressed.

  As another means for obtaining the granulated-sintered cermet particles that do not exhibit the breaking point as described above, the size of the metal particles in the granulated-sintered cermet particles is the same as the granulated-sintered cermet particles. It is also effective to make it smaller than the size of the ceramic particle portion inside. Specifically, the ratio of the average diameter (constant direction average diameter) of the metal particle portion to the average diameter (constant direction average diameter) of the ceramic particle portion is preferably less than 1.5, more preferably 1 or less, and further Preferably it is 0.5 or less, most preferably 0.1 or less. As this ratio decreases, the size of the bonding sites between the ceramic particle portions becomes relatively small, and as a result, cracking of the bonding sites can prevent the granulated-sintered cermet particles from breaking. it can.

  The average diameter (constant direction average diameter) of the ceramic particle portion in the granulated-sintered cermet particles is preferably 6 μm or less, more preferably 1 μm or less, still more preferably 0.5 μm or less, particularly preferably. 0.1 μm or less.

  As another means for obtaining granulated-sintered cermet particles that do not exhibit the breaking point as described above, the average diameter of the metal particle portion relative to the average diameter (volume average diameter) of the granulated-sintered cermet particles ( It is also effective to make the ratio of the (direction average diameter) as small as possible. Specifically, this ratio is preferably 0.15 or less, more preferably 0.1 or less, still more preferably 0.05 or less, and particularly preferably 0.01 or less. As this ratio decreases, the size of the bonding sites between the ceramic particle portions becomes relatively small, and as a result, cracking of the bonding sites can prevent the granulated-sintered cermet particles from breaking. it can.

  The average diameter of the metal particle portion and the average diameter of the ceramic particle portion in the granulated-sintered cermet particles are the average diameter of the metal fine particles and the ceramic fine particles used in the production of the granulated-sintered cermet particles, respectively. The average diameter is generally reflected. However, since it is also affected by the sintering performed during the production of the granulated and sintered cermet particles, the average diameter of the metal fine particles and the average diameter of the ceramic fine particles are generally slightly different.

  Ceramic fine particles used in the production of granulated and sintered cermet particles include, for example, carbides such as tungsten carbide and chromium carbide, borides such as molybdenum boride and chromium boride, nitrides such as aluminum nitride, and silica. It consists of a single component ceramic or a composite ceramic containing at least one selected from a chemical compound and an oxide.

  Similarly, the metal fine particles used in the production of the granulated-sintered cermet particles include, for example, a simple metal or metal alloy containing at least one selected from cobalt, nickel, iron, chromium, silicon, aluminum, copper and silver. Consists of. However, it is preferably made of a metal having a face-centered cubic lattice structure or a body-centered cubic lattice structure. Since a metal having a face-centered cubic lattice structure or a body-centered cubic lattice structure is prone to slip deformation, granulated-sintered cermet particles produced using such a metal do not break when subjected to a compressive load. There is a tendency not to occur easily. Specific examples of the metal having a face-centered cubic lattice structure include nickel, aluminum, and austenitic iron (γ iron). Specific examples of the metal having a body-centered cubic lattice structure include tungsten, molybdenum, ferrite phase iron (α iron), and the like.

  Among these, it is preferable to use a combination of tungsten carbide fine particles and cobalt fine particles. Since tungsten carbide and cobalt have high wettability with each other, that is, they are easy to be compatible with each other, granulated-sintered cermet particles produced by using a combination of tungsten carbide fine particles and cobalt fine particles are subjected to a compressive load. There is a tendency not to break easily.

  It is preferable that the metal particle portions are dispersed as much as possible in the granulated-sintered cermet particles. As a means for dispersing and presenting the metal particle portion, it is effective to sufficiently mix ceramic fine particles and metal fine particles by dry method or wet method, preferably wet method, in the production of granulated and sintered cermet particles. It is.

  The content of the ceramic in the granulated-sintered cermet particles is preferably 95% by mass or less, more preferably 92% by mass or less, and still more preferably 90% by mass or less. In other words, the content of the metal in the granulated-sintered cermet particles is preferably 5% by mass or more, more preferably 8% by mass or more, and further preferably 10% by mass or more. As the ceramic content decreases (in other words, as the metal content increases), the plastic deformability of the granulated-sintered cermet particles is improved. As a result, the powder when used as a thermal spraying powder The adhesion efficiency of is improved.

  The granulated-sintered cermet particles preferably have an outer shape as close to a true sphere as possible. Specifically, the aspect ratio of the granulated / sintered cermet particles is preferably 1.30 or less. Granulated-sintered cermet particles having an aspect ratio of 1.30 or less tend not to break when subjected to a compressive load. The aspect ratio of the granulated-sintered cermet particles is obtained, for example, by dividing the length of the longest side of the smallest rectangle circumscribing the image of the particles by a scanning electron microscope by the length of the short side of the same rectangle. be able to.

  The median diameter of the pores in the granulated-sintered cermet particles is preferably 2.0 μm or less, more preferably 1.7 μm or less, and even more preferably 1.5 μm or less. When a compressive load is applied to the granulated-sintered cermet particles, the granulated-sintered cermet particles may break due to cracks around the pores in the granulated-sintered cermet particles. In this regard, as the median diameter of the pores in the granulated-sintered cermet particles becomes smaller, it is possible to suppress the granulated-sintered cermet particles from breaking due to the occurrence of cracks around the pores. However, from the viewpoint of easy film formation, the median diameter of the granulated and sintered cermet particles is preferably 0.001 μm or more, more preferably 0.005 μm or more, and further preferably 0.01 μm or more.

  The porosity of the granulated-sintered cermet particles is preferably 30% or less, more preferably 25% or less, and still more preferably 20% or less. As the porosity of the granulated-sintered cermet particles decreases, it is possible to prevent the granulated-sintered cermet particles from breaking due to cracking around the pores in the granulated-sintered cermet particles. . However, from the viewpoint of easy film formation, the porosity of the granulated / sintered cermet particles is preferably 0.1% or more, and more preferably 1% or more. The porosity of the granulated-sintered cermet particles can be measured, for example, by a mercury intrusion method.

  The embodiment may be modified as follows.

  -The powder of the said embodiment may contain components other than granulation-sintered cermet particle | grains. For example, it may contain free ceramic particles or metal particles. Alternatively, it may contain melt-ground cermet particles or sintered-ground cermet particles. The melt-pulverized cermet particles are produced by melting a mixture of ceramic fine particles and metal fine particles, cooling and solidifying them, then pulverizing, and then classifying as necessary. Sintered-pulverized cermet particles are produced by sintering and pulverizing a mixture of ceramic fine particles and metal fine particles, and then classifying as necessary.

  The powder product of the above embodiment may be composed of melt-ground cermet particles or sintered-ground cermet particles instead of granulated-sintered cermet particles, or melt-ground cermet particles or sintered particles. In addition to the pulverized-ground cermet particles, other components may be included. However, granulated-sintered cermet particles generally have an outer shape close to a true sphere compared to melt-ground cermet particles and sintered-ground cermet particles, and break when subjected to a compressive load. It tends to be difficult. Also, granulated-sintered cermet particles are suitable because it is relatively easy to arbitrarily control the size and number of pores.

  -When using the powder material of the embodiment as a powder for thermal spraying, the powder material may be sprayed by mixing with other components, or the powder material may be sprayed as it is without mixing with other components. Also good.

  -The powder material of this embodiment is not restricted to being used as a thermal spraying powder, and may be used, for example, as a material for forming a sintered body or as abrasive grains. However, since it contains granulated-sintered cermet particles that do not easily break when a compressive load is applied, it is suitable for applications in which a compressive load acts during use.

  The thermal spraying temperature in the thermal spraying process for thermal spraying the powder material of the present embodiment is not particularly limited, but to suppress spitting due to overmelting of the powder material, or the ceramic fine particles in the granulated-sintered cermet particles In order to suppress thermal deterioration, it is preferably 3,000 ° C. or lower, more preferably 2,500 ° C. or lower, and further preferably 2,000 ° C. or lower.

  -The thermal spraying temperature in the thermal spraying process for thermal spraying the powder material of the present embodiment is not particularly limited, but is preferably 300 ° C or higher, more preferably 400 ° C or higher, in order to obtain high deposition efficiency. Preferably it is 500 degreeC or more.

  -The method of spraying the powder material of this embodiment may be high-speed flame spraying such as high-speed oxygen fuel (HVOF) spraying, or may be explosive spraying or atmospheric pressure plasma spraying (APS). . Alternatively, it may be a low temperature spraying process such as cold spray, warm spray and high velocity air fuel (HVAF) spraying. In cold spraying, a working gas having a temperature lower than the melting point and softening point of the powder is accelerated to supersonic speed, and the accelerated working gas causes the powder to collide and adhere to the substrate in the solid phase. In warm spraying, nitrogen gas is mixed as a cooling gas into a combustion flame using kerosene and oxygen as a combustion aid to form a low-temperature combustion flame compared to HVOF spraying, and this combustion flame is used to heat and Accelerate and collide and adhere to the substrate at supersonic speed. In HVAF thermal spraying, air is used as a combustion aid instead of oxygen to form a combustion flame at a temperature lower than that of HVOF thermal spraying, and the powder is heated and accelerated by this combustion flame to collide and adhere to the substrate.

  Next, the present invention will be described more specifically with reference to examples and comparative examples.

Examples 1-7 and Comparative Examples 1-4 (HVOF spraying)
Powder materials of Examples 1 to 7 and Comparative Examples 1 to 4 made of granulated-sintered cermet particles were prepared, and each powder material was sprayed under the conditions shown in Table 1. Details of each powder are shown in Table 2. Although not shown in Table 2, the average diameter of the granulated-sintered cermet particles of each powder was measured using a laser diffraction / scattering type particle size analyzer “LA-300” manufactured by Horiba, Ltd. As a result, it was 17 μm in all cases.

  The “Composition of Cermet Particles” column in Table 2 shows the chemical composition of the granulated-sintered cermet particles of each powder. In the same column, “WC / 12% Co” represents a cermet composed of 12% by weight of cobalt and the balance of tungsten carbide, and “WC / 12% FeCrNi” represents 12% by weight of iron-chromium-nickel alloy and the balance of the balance. “WC / 10% Co / 4% Cr” represents a cermet composed of 10% by weight of cobalt, 4% by weight of chromium, and the balance of tungsten carbide, and “WC / 20% CrC”. / 7% Ni "represents a cermet composed of 20% by mass of chromium carbide, 7% by mass of nickel and the balance of tungsten carbide. The chemical composition of the granulated and sintered cermet particles was measured using a fluorescent X-ray analyzer “LAB CENTER XRF-1700” manufactured by Shimadzu Corporation.

  In the column “Average diameter of ceramic particle part” and “Average diameter of metal particle part” in Table 2, the average diameter of each of the ceramic particle part and the metal particle part in the granulated-sintered cermet particles of each powder product The result of having measured (direction average diameter) is shown. For this measurement, a scanning electron microscope “S-3000N” manufactured by Hitachi High-Technologies Corporation was used. Specifically, a cross-section of six granulated-sintered cermet particles having a particle size within ± 3 μm from the average diameter of the granulated-sintered cermet particles was observed with a reflection electron image at a magnification of 5,000 times. The average diameter of the ceramic particle portion and the average diameter of the metal particle portion were determined based on the obtained particle cross-sectional photograph. For reference, cross-sectional photographs of the granulated-sintered cermet particles of Example 2 and Comparative Example 2 are shown in FIGS. 2 and 3, respectively.

  In the column “average diameter of metal particle portion / average diameter of ceramic particle portion” in Table 2, the average diameter of the metal particle portion determined as described above for each powder is divided by the average diameter of the ceramic particle portion. The value obtained by this is shown.

  The “pore median diameter” column in Table 2 shows the result of measuring the median diameter of the pores in the granulated and sintered particles of each powder. More specifically, measurement was performed using a mercury intrusion porosimeter “AutoPore IV 9500” manufactured by micromeritics, Inc. under the conditions of a mercury contact angle of 130 ° and a surface tension of 485 dynes / cm (0.485 N / m). From the results, data of 66 psi (0.045 MPa) or more was extracted to determine the median diameter of the pores.

  In the column “Ratio of cermet particles not showing break point” in Table 2, the maximum value of the granulated and sintered cermet particles of each powder is 981 mN at a load speed of 12.9 mN / s. The proportion of granulated-sintered cermet particles that do not show a breaking point in the stress-strain diagram obtained when a compressive load increasing to a maximum is applied to a micro compression tester (MCTE-500 manufactured by Shimadzu Corporation). The result measured using this is shown. The ratio of the granulated-sintered cermet particles not showing the breaking point is the percentage of the 12 granulated-sintered cermet particles having a particle diameter of 50 μm or less arbitrarily selected from the powders. It was calculated as the proportion of food.

  The “spraying temperature” column in Table 2 shows the process temperature when each powder material is sprayed under the conditions shown in Table 1.

  In the “Adhesion efficiency” column of Table 2, the value obtained by dividing the weight of the sprayed coating obtained by spraying each powdered product by the weight of the sprayed powdered product is shown as a percentage.

As shown in Table 2, when the powders of Examples 1 to 7 were used, higher adhesion efficiency could be obtained than when the powders of Comparative Examples 1 to 4 were used. .

Examples 8 to 11 and Comparative Examples 5 to 7 (cold spray)
The powders of Examples 8 to 11 and Comparative Examples 5 to 7 made of granulated and sintered cermet particles were prepared, and each powder was sprayed under the conditions shown in Table 3. Details of each powder are shown in Table 4. Although not shown in Table 4, the average diameter of the granulated-sintered cermet particles of each powder was measured using a laser diffraction / scattering particle size measuring instrument “LA-300” manufactured by Horiba, Ltd. As a result, it was 17 μm in all cases.

  The “Composition of cermet particles” column in Table 4 shows the chemical composition of the granulated-sintered cermet particles of each powder. In the same column, “WC / 25% FeCrNi” represents a cermet composed of 25 mass% iron-chromium-nickel alloy and the balance tungsten carbide, and WC / 25% FeSiCr ”represents 25 mass% iron-silicon-chromium. This represents a cermet composed of an alloy and the balance tungsten carbide.The chemical composition of the granulated-sintered cermet particles was measured using a fluorescent X-ray analyzer “LAB CENTER XRF-1700” manufactured by Shimadzu Corporation. .

  In the column “Average diameter of ceramic particle portion” and “Average diameter of metal particle portion” in Table 4, the respective average diameters of the ceramic particle portion and the metal particle portion in the granulated-sintered cermet particles of each powder product The result of having measured (direction average diameter) is shown. For this measurement, a scanning electron microscope “S-3000N” manufactured by Hitachi High-Technologies Corporation was used. Specifically, a cross-section of six granulated-sintered cermet particles having a particle size within ± 3 μm from the average diameter of the granulated-sintered cermet particles was observed with a reflection electron image at a magnification of 5,000 times. The average diameter of the ceramic particle portion and the average diameter of the metal particle portion were determined based on the obtained particle cross-sectional photograph.

  In the “average diameter of metal particle portion / average diameter of ceramic particle portion” column in Table 4, the average diameter of the metal particle portion obtained as described above for each powder is divided by the average diameter of the ceramic particle portion. The value obtained by this is shown.

  The “pore median diameter” column in Table 4 shows the result of measuring the median diameter of the pores in the granulated-sintered particles of each powder. More specifically, measurement was performed using a mercury intrusion porosimeter “AutoPore IV 9500” manufactured by micromeritics, Inc. under the conditions of a mercury contact angle of 130 ° and a surface tension of 485 dynes / cm (0.485 N / m). From the results, data of 66 psi (0.045 MPa) or more was extracted to determine the median diameter of the pores.

  In the “Ratio of cermet particles not showing break point” column in Table 4, the maximum value of the granulated and sintered cermet particles of each powder is 200 mN at a load speed of 12.9 mN / s. The proportion of granulated-sintered cermet particles that do not show a breaking point in the stress-strain diagram obtained when a compressive load increasing to a maximum is applied to a micro compression tester (MCTE-500 manufactured by Shimadzu Corporation). The result measured using this is shown. The ratio of the granulated-sintered cermet particles not showing the breaking point does not show the breaking point among the 12 granulated-sintered cermet particles having a particle diameter of 30 μm or less arbitrarily selected from each powder. It was calculated as the proportion of food.

  The “spraying temperature” column of Table 4 shows the process temperature when each powder material is sprayed under the conditions shown in Table 3.

  In the “Adhesion efficiency” column of Table 4, each powder product is sprayed on the basis of the thickness of the spray coating formed per pass of the spray nozzle when each powder product is sprayed under the conditions shown in Table 3. The result of having evaluated adhesion efficiency is shown. Specifically, when the thickness of the sprayed coating formed per pass was 200 μm or more, it was evaluated as good, and when it was less than 200 μm, it was evaluated as defective.

As shown in Table 4, when the powders of Examples 8 to 11 were used, higher adhesion efficiency could be obtained than when the powders of Comparative Examples 5 to 7 were used. .

Claims (12)

  A powder containing ceramic and metal composite particles, wherein at least some of the composite particles increase to a maximum value of 10 mN or more at a load speed of 15.0 mN / s or less. A powder product characterized by showing no breaking point in a stress-strain diagram obtained when a load is applied.   The powder object according to claim 1, wherein a ratio of the composite particles not exhibiting the breaking point in the composite particles is 10% or more.   The powder according to claim 1, wherein the composite particle includes a metal particle portion having an average diameter of 3 μm or less.   The powder according to claim 1 or 2, wherein the composite particle includes a metal particle portion and a ceramic particle portion, and a ratio of an average diameter of the metal particle portion to an average diameter of the ceramic particle portion is less than 1.5.   The composite particle includes a metal particle portion and a ceramic particle portion, a ratio of an average diameter of the metal particle portion to an average diameter of the ceramic particle portion is less than 1.5, and an average diameter of the metal particle portion is 3 μm or less. Item 3. The powder according to Item 1 or 2.   The powder object according to any one of claims 1 to 5, wherein a ratio of an average diameter of the metal particle portion to an average diameter of the composite particles is 0.15 or less.   The powder according to any one of claims 1 to 6, wherein the composite particles have an aspect ratio of 1.30 or less.   The powder according to claim 1, wherein the composite particles include pores having a median diameter of 2.0 μm or less.   The powder according to any one of claims 1 to 8, wherein the composite particles have a porosity of 30% or less.   It is used as a powder for thermal spraying, The powder object as described in any one of Claims 1-9 characterized by the above-mentioned.   The powder material according to claim 10, wherein the powder material is sprayed at a spraying temperature of 3,000 ° C. or less.   A method for forming a thermal spray coating comprising spraying the powder material according to any one of claims 1 to 9 at a thermal spraying temperature of 3,000 ° C or lower.