Method for producing powder mixture for powder metallurgy, and method for producing sintered body

Abstract

The present invention provides a method for producing a powder mixture for powder metallurgy, which allows production of a green compact having both high density and high lubricity (low demolding force). The method, according to the present invention, for producing a powder mixture for powder metallurgy including an iron-base powder, a mechanical characteristic-improving powder and a lubricant, the method includes the steps of: mixing the iron-base powder and / or the mechanical characteristic-improving powder with an amide-based lubricant solution; removing a solvent in the solution; and coating the surface of the iron-base powder and / or the mechanical characteristic-improving powder with an amide-based lubricant.

Description

technical field

[0001] The present invention relates to a method for producing a mixed powder for powder metallurgy, and a method for producing a sintered body using the mixed powder for powder metallurgy obtained by the production method. Background technique

[0002] Mixed powders for powder metallurgy are generally iron-based powders such as pure iron powder and iron-based alloy powder as the main raw material, and are used to improve the mechanical properties of the final sintered body (such as strength properties and processing properties, etc.) It is produced by mixing powder for an alloy of a composition of 1, mechanical property improving powder such as graphite powder, and a powdery lubricant (for example, Patent Document 1).

[0003] Here, the lubricant is used to reduce the friction resistance between the green compact and the wall surface of the metal mold when the mixed powder for powder metallurgy is filled into the metal mold for compression molding to form a ...

Examples

experiment example 1

[0087] (Preparation of amide lubricant solution)

[0088] Add 4 parts of N-oleyl palmitamide (manufactured by Nippon Seika Co., Ltd.) as an amide lubricant to 20 parts of toluene as a solvent, and mix while heating to about 60°C to prepare an amide lubricant solution .

[0089] (Preparation of mixed powder for powder metallurgy)

[0090] The obtained amide-based lubricant solution was added to 100 parts of pure iron powder (manufactured by Kobe Steel Works, Ltd., 300M, particle size 50-150μm) as an iron-based powder and mixed, and then separately added as mechanical property improving powder 2.0 parts of copper powder (MAKIN METAL POWDERS, AHF-100, particle size 30-50 μm) and 0.8 parts of graphite powder (Japan Graphite Industry Co., Ltd., JCPBK, particle size 3-5 μm) are mixed, and then the toluene is distilled off under reduced pressure, A mixed powder for powder metallurgy was obtained (the addition amount of the amide-based lubricant to 100 parts of the total amount of t...

experiment example 2、3

[0096] (Preparation of amide-based lubricant solution, preparation of mixed powder for powder metallurgy, compression molding)

[0097] Add the amide-based lubricant solution so that the amount of the amide-based lubricant added is 0.4 parts (experimental example 2) or 0.5 part (experimental example 3) relative to the total amount of 100 parts of the iron-based powder and the mechanical property-improving powder, otherwise The outside is the same as in Experimental Example 1, and compressed powders 2-1 and 2-2 (above are Example 2), and compressed powders 3-1 and 3-2 (above is Experimental Example 3) were obtained.

[0098] (Characteristics of compressed powder)

[0099] The densities of the obtained green compacts 2-1 and 2-2 and the green compacts 3-1 and 3-2, and the demolding pressure when they were released from the metal mold were measured, respectively. The results are shown in Table 1.

experiment example 4

[0101] (Preparation of amide-based lubricant solution, preparation of mixed powder for powder metallurgy, compression molding)

[0102] As the amide-based lubricant, ethylene bisoleamide was used instead of the N-oleyl palmitamide (manufactured by Dainippon Chemical Industry Co., Ltd.) used in Experimental Example 1, except that it was the same as in Experiment 1, and the pressure was obtained. Powder 4-1, 4-2.

[0103] (Characteristics of compressed powder)

[0104] The densities of the obtained green compacts 4-1 and 4-2, and the release pressures at the time of release from the mold were measured, respectively. The results are shown in Table 1.

technical field

[0001] The present invention relates to a method for producing a mixed powder for powder metallurgy, and a method for producing a sintered body using the mixed powder for powder metallurgy obtained by the production method. Background technique

[0002] Mixed powders for powder metallurgy are generally iron-based powders such as pure iron powder and iron-based alloy powder as the main raw material, and are used to improve the mechanical properties of the final sintered body (such as strength properties and processing properties, etc.) It is produced by mixing powder for an alloy of a composition of 1, mechanical property improving powder such as graphite powder, and a powdery lubricant (for example, Patent Document 1).

[0003] Here, the lubricant is used to reduce the friction resistance between the green compact and the wall surface of the metal mold when the mixed powder for powder metallurgy is filled into the metal mold for compression molding to form a ...

Examples

experiment example 1

[0087] (Preparation of amide lubricant solution)

[0088] Add 4 parts of N-oleyl palmitamide (manufactured by Nippon Seika Co., Ltd.) as an amide lubricant to 20 parts of toluene as a solvent, and mix while heating to about 60°C to prepare an amide lubricant solution .

[0089] (Preparation of mixed powder for powder metallurgy)

[0090] The obtained amide-based lubricant solution was added to 100 parts of pure iron powder (manufactured by Kobe Steel Works, Ltd., 300M, particle size 50-150μm) as an iron-based powder and mixed, and then separately added as mechanical property improving powder 2.0 parts of copper powder (MAKIN METAL POWDERS, AHF-100, particle size 30-50 μm) and 0.8 parts of graphite powder (Japan Graphite Industry Co., Ltd., JCPBK, particle size 3-5 μm) are mixed, and then the toluene is distilled off under reduced pressure, A mixed powder for powder metallurgy was obtained (the addition amount of the amide-based lubricant to 100 parts of the total amount of t...

experiment example 2、3

[0096] (Preparation of amide-based lubricant solution, preparation of mixed powder for powder metallurgy, compression molding)

[0097] Add the amide-based lubricant solution so that the amount of the amide-based lubricant added is 0.4 parts (experimental example 2) or 0.5 part (experimental example 3) relative to the total amount of 100 parts of the iron-based powder and the mechanical property-improving powder, otherwise The outside is the same as in Experimental Example 1, and compressed powders 2-1 and 2-2 (above are Example 2), and compressed powders 3-1 and 3-2 (above is Experimental Example 3) were obtained.

[0098] (Characteristics of compressed powder)

[0099] The densities of the obtained green compacts 2-1 and 2-2 and the green compacts 3-1 and 3-2, and the demolding pressure when they were released from the metal mold were measured, respectively. The results are shown in Table 1.

experiment example 4

[0101] (Preparation of amide-based lubricant solution, preparation of mixed powder for powder metallurgy, compression molding)

[0102] As the amide-based lubricant, ethylene bisoleamide was used instead of the N-oleyl palmitamide (manufactured by Dainippon Chemical Industry Co., Ltd.) used in Experimental Example 1, except that it was the same as in Experiment 1, and the pressure was obtained. Powder 4-1, 4-2.

[0103] (Characteristics of compressed powder)

[0104] The densities of the obtained green compacts 4-1 and 4-2, and the release pressures at the time of release from the mold were measured, respectively. The results are shown in Table 1.

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