JPS62109905A - Production of composite metallic powder - Google Patents

Abstract

PURPOSE:To produce composite metallic powder suitable for a sintering material with a simple stage by supplying reinforcing powder having a high m.p. from the upper part of the central hole of a nozzle for spraying molten metal flow and uniformly distributing the reinforcing particles. CONSTITUTION:The molten metal 5 of an Ni-base alloy, etc. having a prescribed compsn. is poured into a tundish 4 and is dropped in the form of the molten metal flow 3 from the bottom of the tundish 4 toward the central hole 1a of the spraying nozzle 1. High-pressure fluid 10 such as gaseous Ar is supplied to the nozzle 1 to form a spraying medium 2 of an inverted circular circular cone shape internally having a negative pressure to the bottom surface of the nozzle 1. The reinforcing powder 8 of the granular or short fiber-like Y2O3, etc. having the high m.p. is supplied through a supply pipe 7 in this state from the upper side of the central hole 1a of the nozzle 1. The reinforcing powder 8 is combined with the molten metal which is pulverized at the top end part of the spraying medium 2. The composite metallic powder 9 in which the reinforcing powder 8 is finely and uniformly dispersed is obtd. by the above- mentioned method.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention is applicable to the production of dispersion-strengthened composite sintered metal materials having predetermined properties such as strength, heat resistance, and wear resistance. [Prior art] In general, 1 dispersion strength (for example, 1 dispersion strength, 1H type composite sintered metal material is manufactured by a powder metallurgy method) is used. Multiple types of raw material powders including reinforcing powders are prepared, these raw material powders are blended into a predetermined composition, and after dry or wet mixing, this mixed powder is usually vacuum sealed in a metal container and heated to a predetermined temperature. A process of hot extrusion or hot isostatic pressing at high temperatures is used.

[Problem that the invention seeks to solve]

However, in the above powder metallurgy method, mixing of the blended powder requires a significantly long time, for example, about 20 to 50 hours.
This long mixing time is a bottleneck to process efficiency. Therefore, raw material powder 1 that does not require a mixing process
In other words, if a composite metal powder having a predetermined final component composition can be prepared, the manufacturing process of composite sintered metal materials can be streamlined.

[Means for solving the melting point]

Therefore, based on the above-mentioned viewpoints, the present inventors, when manufacturing a sintered metal rotary material by a powder metallurgy method,
A composite metal powder that can be used as a raw material powder without the need for a mixing process is produced in a simple process.
As a result of conducting research in order to manufacture the product at a low cost, the molten metal flow is made to flow down toward the center hole of a horizontally arranged spray nozzle, while high pressure fluid such as high pressure air or Takada water is supplied into the spray nozzle. An inverted conical spray medium with a negative pressure inside is formed on the face of the spray nozzle, and when the molten metal stream is pulverized at the tip of the spray medium to produce metal powder, the spray nozzle From above the center hole of the molten metal flow, particles of granular or short fibrous strong powder such as ceramic powder, intermetallic powder, and whiskers having a higher melting point than the metals constituting the molten metal flow are poured into the molten metal flow. When supplied, a composite metal powder is obtained in which the reinforcing particles supplied as the above-mentioned strong powder are uniformly distributed, and the resulting composite metal powder has a composition of the molten metal flow and the above-mentioned strong Knowledge that by adjusting the composition and supply ratio of the powder, it is possible to make it have a predetermined final component composition, that is, the same component composition as the composite sintered metal material to be finally produced. I got it.

This invention was made based on the above-mentioned knowledge, but since the interior of the spray medium formed on the lower surface of the spray nozzle d as described above inevitably becomes negative, the atmosphere in the upper part of the spray nozzle is forcibly sucked into the spray nozzle, and this suction hole allows the strong (hyponic) material to be smoothly fed into the spray nozzle along with the molten metal flow.
At the tip of the atomizing medium having an inverted conical shape, that is, near the focal point of the atomizing medium, more than 99% of the strong F powder mixes into the molten metal flow and is immediately pulverized into fine particles. In this case, when gas is used as the high-pressure fluid, the powder produced will have a spherical shape, whereas when a liquid is used, it will have an irregular shape.

〔Example〕

Next, the method of the present invention will be specifically explained using examples.

Example 1 First, using the equipment shown in the schematic explanatory diagram in Figure 1,
%, Cr: 20%, M: 1.54, Ti: 2.3
N as a molten total refractory 5 heated to 1500°C, with a composition containing Ni and unavoidable impurities.
The i-base alloy molten metal is injected into the preheated dandysh 4 and passed from the bottom 7) to the center hole 1a of the horizontally arranged injection nozzle 1 as a molten metal stream 3 with a diameter of 25 Mφ. Gas E: 25 was supplied to the spray nozzle 1.
Ar gas is supplied as the high-pressure fluid 10 under the condition of Kg/i-gas flow rate = 14 N m3/wL, and an inverted conical spray medium 2 whose internal pressure is negative is supplied to the lower surface of the spray nozzle 1. A shape 1 is drilled, and in this state, an average of high-fever powder 8 is sent from above the center hole of the cutting jet 31/drill 1 through the supply pipe 7 by the feeding device 6 using Ar as the carrier gas. Ittria (Y2O3) with particle size: 1 μm
) powder in a ratio of 1.25 parts to the composite metal powder to be manufactured, and at the tip of the jet spout 2, the molten metal end flow 3 mixed with the A composite Ni-based alloy powder as composite metal powder 9 was produced by heating the composite metal powder 9.The composite Ni-based alloy powder obtained as a result was heated to an average particle size of 80 μm, and was hardened into a Ni-based alloy base. (
It had a structure in which Y2O3 particles, which are particles of carbon dioxide, were finely and uniformly dispersed.

Next, the composite Ni produced by the method of the present invention as described above is
The base alloy powder was packed in a stainless steel J can, evacuated and sealed, and then subjected to hot isostatic pressing at a temperature of 115 (2000 atm) and a holding time of 1 hour. After that, (]Jj: After holding at 1080°C for 8 hours, air cooling, and after holding at a temperature of near 00°C for 16 hours, air cooling is applied. Finally, the stainless steel can is removed by machining and composite A Ni-based alloy/sintered material (hereinafter referred to as the composite N1-based material of the present invention) was produced.

On the other hand, for the purpose of comparison, as raw material powder, average particle size: 5μ
Ni powder with m, 100 pm (7') Cr powder, 200 μm Ni-A4-Ti alloy (in weight %, M: 30%, Ti: 30% aW) powder,
Same 200μm N1-M alloy (Chongjinjin A#: 20
These raw material powders were blended to have the same composition as the sintered material of the present invention, placed in an attritor, and heated in an inert gas atmosphere. A comparatively soft composite Ni-based material was manufactured under the same conditions as those for the above-described composite Ni-based material of the present invention, except that a mixed powder obtained by mixing for 20 hours was used.

The composite Ni-based material of the present invention and the relatively soft composite Ni-based material obtained as a result showed the yield strength (0, 2 width) and breaking strength (temperature: held at 1000° C. for 1000 hours) shown in Table 1.

Table 1 Example 2 A pure copper molten metal heated to 1200°C was used as the molten metal 5, and acid f hyaluminum minilum (A/203') powder having an average particle size of 15 μm was used as the molten metal 5. was supplied at a ratio of 1.1 weight to Cu, and N2 gas was used as a carrier gas for this strong powder, and 200 kg of Takani was used as the high pressure fluid 10.
i, Flow @: Q, 1ta3/Under the same conditions as in Example 1 except for using turtle high aqua regia, the average particle size was 50 μm, and the average particle size was less than 1 μm in the copper matrix. A/! 2
A composite Cu alloy powder having a structure in which 03 particles were uniformly dispersed was manufactured.

Next, the composite Cu produced by the method of the present invention as described above
For alloy powder, in hydrogen atmosphere, temperature: 800 ° C.
Heat reduction treatment under time retention conditions? : After applying, this was sealed in a pure copper container in an Ar gas atmosphere, and extrusion temperature: 9
00'C1 Extrusion ratio: Composite by performing two hot extrusion processes under the conditions of 20:1 On the other hand, for comparison purposes, Cu powder with an average particle size of 50 μm and Cu powder with an average particle size of 0.05 μm were used as raw material powders.
A/203 powder was used, and the composition was the same as that of the Cu-based material of the present invention, that is, A7!203: 1.1 G+%
, Cu: 1 remaining sword, and put this into the attritor.

20E+ in Ar atmosphere? f and hot extrusion using this mixed powder under the same conditions as those employed to produce the composite Cu-based material of the present invention (
A comparative composite Cu-based material was thus produced.

The resulting composite Cu-based material of the present invention and specific soft composite Cu-based material exhibited tensile strength and elongation shown in the cJz table.

〔Effect of the invention〕

As is clear from the 11-δ results shown in Examples 1 and 2 above, according to the method of the present invention, one reinforcing particle is fine and uniform.
C-distributed composite metal powder in a simple process.

It can be produced quickly and at low cost, and when used as a raw material powder, it is equivalent to or even better than composite sintered metal materials produced through conventional mixing processes that require a long time. A composite sintered metal material with more refined properties can be produced without substantially requiring a mixing step, which greatly improves the rationality of the production process.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram showing an actual IN device of the present invention. 1. Spray nozzle, 2. Spray medium. 3... Molten metal flow, 4... Tundish. 5... Molten metal, 6... Delivery equipment prayer. 7... Supply pipe, 8... Strong powder. 9... Composite metal powder, 10... High pressure fluid.

Claims (1)

[Claims] A stream of molten metal is caused to flow down toward the central hole of a horizontally arranged spray nozzle, while a high-pressure fluid is supplied into the spray nozzle to form an inverted cone-shaped spray medium with negative pressure inside at the lower surface of the spray nozzle. When producing metal powder by pulverizing the molten metal flow at the tip of the spray medium, a metal having a higher melting point than the metal constituting the molten metal flow is introduced from above the center hole of the spray nozzle. A method for producing composite metal powder characterized by supplying reinforcing powder in the form of granules or short fibers.