KR20190123965A - Fabrication of spherical powders for high heat resistance intermetallic alloy using the rf plasma - Google Patents

Abstract

The present invention relates to a method for manufacturing intermetallic compound powder of a spherical super heat-resisting alloy. In particular, according to the present invention, an intermetallic compound of a super heat-resisting alloy manufactured by an arc-melting method is pulverized to be made into intermetallic compound powder of the super heat-resisting alloy, and then the intermetallic compound of a super heat-resisting alloy undergoes an RF plasma process to be made into intermetallic compound powder of the super heat-resisting alloy with a spherical core. Next, the manufactured intermetallic compound powder of the super heat-resisting alloy with the spherical core is coated with molybdenum oxide (MoO_3) before being deoxidized to produce a molybdenum (Mo) nanoparticle on the surface of the intermetallic compound powder of the spherical super heat-resisting alloy, before secondly undergoing the RF plasma process. Resultantly, after two times of the RF plasma processes, manufactured is the intermetallic compound powder of the spherical super heat-resisting alloy in a core-shell shape, wherein a core includes the intermetallic compound of the super heat-resisting alloy, and a shell includes molybdenum (Mo).

Description

Method for preparing intermetallic compound powder of spherical superalloy using RF plasma and spherical superalloy powder intermetallic compound prepared according to the present invention

The present invention relates to a method for producing intermetallic compound powder of spherical superalloy, and more particularly, to spherical superalloy using spherical superalloy using RF plasma for spherical intermetallic compound powder of superalloy. The present invention relates to a method for preparing intermetallic powder and to spherical superalloy powder intermetallic compound prepared accordingly.

In general, three-dimensional (3D) printing technology is a technology for manufacturing a three-dimensional solid shape by stacking layers by using a special material ink, has been widely used in various fields. In order to improve the flowability of ink, which is an important factor for printing three-dimensional solid shape in the field of 3D printer, it is required to manufacture the material powder constituting the ink in spherical shape, and various attempts have been made to produce spherical powder for 3D printing. , Korean Patent No. 10-1421244 has been presented for the production method of spherical titanium (Ti) powder.

However, no technique has been proposed to produce spherical powders for intermetallic compounds of super heat-resistant alloys that can be used by showing sufficient oxidation resistance and high temperature strength even at a high temperature of 1000 ° C. or higher. Recently, 3D printing technology has been used to produce spherical powders. Turbine blade manufacturing is also required, and therefore, there is a need for the development of spherical technology of super-alloy intermetallic compounds.

Korea Patent Registration No. 10-1421244

Therefore, an object of the present invention is to pulverize the intermetallic compound of the super-alloy alloy prepared by the arc melting method (arc-melting) to make the intermetallic compound powder of the super-alloy alloy, then RF plasma treatment of the spherical super-alloy alloy Molybdenum oxide (MoO ₃ ) is coated on the prepared intermetallic compound powder of the spherical superheat resistant alloy and reduced to form molybdenum (Mo) nanoparticles on the surface of the intermetallic compound powder of the spherical superalloy. And a method of preparing a core-shell-type spherical superheat-resistant alloy intermetallic compound powder through two RF plasma treatment processes of secondary RF plasma treatment and core-shell spherical superheat resistance prepared accordingly. An alloy intermetallic compound powder is provided.

In order to achieve the above object, the spherical superalloy powder of the intermetallic compound manufacturing method of the present invention, the alloy ingot manufacturing step of producing an intermetallic compound ingot of super-resistant alloy through arc-melting, A pulverizing step of pulverizing the intermetallic compound ingot to produce a core intermetallic compound powder, and a first RF plasma step of preparing a spherical core intermetallic compound powder by RF plasma treatment of the core intermetallic compound powder, wherein 1 oxidizing the spherical core intermetallic compound powder surface produced on the primary plasma step molybdenum (MoO ₃₎ the coating to form a shell, and molybdenum oxide in the coating step (MoO ₃₎ shell is oxidized in the spherical core intermetallic compound powder formed on the surface molybdenum (MoO ₃₎ for reducing the molybdenum (Mo), molybdenum (Mo) reduced to form nanoparticles in spherical core intermetallic compound powder surface And a spherical superheat resistant alloy in the form of a core-shell (core-shell) surrounded by a molybdenum (Mo) shell by RF plasma treatment of a spherical core intermetallic compound powder formed on the surface of the system and the molybdenum (Mo) nanoparticles subjected to the reduction step. It may include a secondary RF plasma step for producing the intermetallic powder.

The alloy ingot manufacturing step may be performed by heating molybdenum (Mo), silicon (Si) and boron (B) at a temperature of 1400 ° C. to 1800 ° C. under an inert gas atmosphere to form an Mo ₅ SiB ₂ phase (T2) as an intermetallic compound of the superalloy alloy. Phase) and the Mo ₃ Si phase (A15 phase), and an ingot in which Mo ₅ SiB ₂ phase (T2 phase) or Mo ₃ Si phase (A15 phase) is present alone is produced or Mo ₅ SiB ₂ phase and Mo ₃ Si phase can be manufactured in an ingot, which is mixed in an appropriate ratio. If the Mo ₅ SiB ₂ phase and the Mo ₃ Si phase are mixed, the ratio of the Mo ₅ SiB ₂ phase and the Mo ₃ Si phase can be arbitrarily adjusted. For example, the Mo ₅ SiB ₂ phase: Mo ₃ Si phase is 0:10 to 10 May be mixed at a ratio of zero.

In the pulverizing step, the intermetallic compound ingot may be pulverized with a pulverizer under an inert gas atmosphere.

The particle size of the core intermetallic compound powder pulverized in the pulverizing step is preferably 1 to 100 μm.

In the first RF plasma step, spherical core intermetallic compound powder is applied by applying plasma power of 3 to 10 kW while flowing the core intermetallic powder with argon (Ar) gas as an inert gas to an RF plasma reaction chamber. can do.

In the reducing step, molybdenum oxide (MoO ₃ ) may be reduced to molybdenum (Mo) by heating a spherical core intermetallic powder having a surface of a molybdenum oxide (MoO ₃ ) shell at a temperature of 300 ° C. to 1200 ° C. under a hydrogen atmosphere. have.

In the secondary RF plasma step, the spherical core intermetallic compound powder formed on the surface of the molybdenum (Mo) nanoparticles is placed in an RF plasma reaction chamber and plasma power of 3 to 10 kW is applied to spherical superalloy powder of the spherical superalloy alloy. Can be prepared.

After the grinding step and before the first RF plasma step, a classification step of classifying the pulverized core superalloy intermetallic compound powder may be further included.

In addition, the intermetallic compound powder of the spherical superalloy alloy of the present invention for achieving the above object is prepared by the above method, the intermetallic compound of the spherical superalloy of the core-shell (core-shell) type The powder core may include an intermetallic compound of a super heat resistant alloy, and the shell may include molybdenum (Mo).

The intermetallic compound of the super heat resistant alloy is Mo ₅ SiB ₂ phase (T2 phase) and Mo ₃ Si phase (A15 phase), and Mo ₅ SiB ₂ phase (T2 phase) or Mo ₃ Si phase (A15 phase) alone It may be present in the Mo ₅ SiB ₂ phase and Mo ₃ Si phase may be a mixed phase in an appropriate ratio. If the Mo ₅ SiB ₂ phase and the Mo ₃ Si phase are mixed, the ratio of the Mo ₅ SiB ₂ phase and the Mo ₃ Si phase can be arbitrarily adjusted. For example, the Mo ₅ SiB ₂ phase: Mo ₃ Si phase is 0:10 to 10 May be mixed at a ratio of zero.

Through the manufacturing method of the intermetallic compound powder of the spherical superalloy alloy of the present invention it was possible to implement the intermetallic compound of the superalloy alloy in the form of a spherical powder by using an RF plasma.

In addition, the core-shell containing the intermetallic compound of the super-heat-resistant alloy in the core (core), the molybdenum (Mo) in the shell (core) through the manufacturing method of the spherical super-alloy powder of the intermetallic compound of the present invention By preparing the intermetallic compound powder of spherical super heat resistant alloy which is a composite powder in the form of (core-shell), there is an effect that can be used as a raw material for 3D printing in the future.

1 is a schematic flowchart of a method for preparing intermetallic compound powder of spherical superheat resistant alloy according to an embodiment of the present invention.
Figure 2 is a photograph of a spherical core intermetallic compound powder prepared according to the RF plasma power applied in the first RF plasma step of the present invention with a scanning electron microscope (Scanning Electron Microscope, SEM).
FIG. 3 is a photograph of a cross section of an intermetallic compound powder of a spherical superalloy prepared in a second RF plasma step according to an embodiment of the present invention with a scanning electron microscope (SEM).

Hereinafter, the preparation of the intermetallic compound powder of the spherical superheat resistant alloy of the present invention will be described in more detail with reference to the accompanying drawings. As will be described below, one of ordinary skill in the art to which the present invention pertains may be embodied in many different forms and is not limited to those described herein.

The intermetallic compound powder manufacturing method of the spherical super-alloy alloy of the present invention, as shown in Figure 1, arc-melting step (S11), grinding step (S12), classification step (S13), primary RF Plasma step S14, classification step S15, molybdenum oxide (MoO ₃ ) coating step (S16), reduction step (S17), and the secondary RF plasma step (S18).

Arc-melting step (S11) is a step of producing an intermetallic compound ingot of super heat-resistant alloy through the arc-melting method, a certain amount of molybdenum (Mo), silicon (Si) and boron Ingot in which Mo ₅ SiB ₂ phase (T2 phase) or Mo ₃ Si phase (A15 phase) is solely present as the intermetallic compound of the superheat resistant alloy by heating (B) at a temperature of 1400 ° C. to 1800 ° C. under an inert gas atmosphere. Or an intermetallic compound ingot of a super heat resistant alloy in which Mo ₅ SiB ₂ phase and Mo ₃ Si phase are mixed at an appropriate ratio.

The inert gas used in the arc-melting step S11 may be any one or more selected from argon, helium, and neon, to prevent oxidation of the raw material powder, and preferably, argon gas may be used. Can be.

Grinding step (S12) is a step of grinding the intermetallic compound ingot prepared in step S11 to have a particle size within a certain size range, the intermetallic compound ingot is pulverized by a grinder in an inert gas atmosphere to core powder intermetallic compound Can be formed.

The type of grinder used at this time is not particularly limited, but specifically, a jaw crusher, a disc mill, a rotary cutter mill, a cutter mill, a crusher shred It may include any one selected from the group of crushing device consisting of a crusher and a chopper, but is not limited to the above-described example.

The particle size of the core intermetallic compound powder obtained after the grinding step may be 1 to 100 μm.

After the grinding step, the final intermetallic compound powder is subjected to a classification step (S13) of classifying the core intermetallic compound powders obtained after the grinding by particle size.

 The primary RF plasma step S14 has a predetermined particle size obtained through the classification step S13 while injecting argon (Ar) gas into the inert gas so that the pressure of the inert gas is maintained at 50 to 90 kPa in the RF plasma chamber. Preparing a spherical core intermetallic powder by pouring the core intermetallic powder into an RF plasma reaction chamber at a rate of 500 to 800 g / h and applying a 3 to 10 kW RF plasma power to melt the surface of the powder to form a spherical core intermetallic powder. to be.

Figure 2 is a photograph of a spherical core intermetallic compound powder prepared according to the RF plasma power applied in the first RF plasma step of the present invention by a scanning electron microscope (SEM), RF plasma power of less than 6kW as shown When 3kW, 4kW and 5kW were applied, some particles could not be spherical. When RF plasma powers of 6kW, 7kW and 8kW were applied, the core intermetallic compound powder could be observed to be spherical. In order to spheronize the core intermetallic powder, it is preferable to apply RF plasma power of 6 kW or more. However, the smaller the size of the powder, the lower the RF power can be spherical, so the power of the fully spherical RF may vary depending on the size of the powder after grinding, and the RF plasma power can be adjusted as needed.

In order to spheronize the core intermetallic powder, it is preferable to apply RF plasma power of 6 kW or more.

In the classification step S15, the spherical core intermetallic compound powder is classified once again in order to uniformize the spherical spherical core intermetallic powder through the first RF plasma step S14. Preferably, a particle size of 25 to 45 μm is used in both the Mo ₅ SiB ₂ phase (T2 phase), the Mo ₃ Si phase (A15 phase), and the spherical core intermetallic powder in which the Mo ₅ SiB ₂ phase and the Mo ₃ Si phase are mixed. It can classify as spherical core intermetallic compound powder which has.

Molybdenum oxide (MoO ₃ ) coating step (S16) is to form a molybdenum oxide (MoO ₃ ) shell on the surface of the spherical core intermetallic compound prepared in the first plasma step, by using a tubular mixing (Tubular mixing) a spherical core may be coated with molybdenum oxide (MoO ₃₎ in the intermetallic compound powder surface.

Here, in the case of turbulent mixing, a stainless steel ball, a spherical core intermetallic compound powder, and molybdenum oxide (MoO ₃ ) powder may be added and mixed for 1 to 3 hours to perform a coating process. see for intermetallic compound powder and a molybdenum oxide (MoO ₃₎ the blending ratio of the total combined amount of the powder, for example, 1: 2 or 1: preferably mixed at a weight ratio of 3, but according to need is not limited to those of ordinary skill in the art to control Can be.

A reducing step (S17) is a molybdenum oxide (MoO ₃₎ coating a molybdenum oxide in the step (S16) (MoO ₃₎ the shell is reduced to molybdenum (MoO ₃₎ oxidation in the spherical core intermetallic compound powder formed on the surface of molybdenum (Mo) Molybdenum (Mo) nanoparticles are formed on the surface of the spherical core intermetallic compound powder.

Specifically, the reduction step include a molybdenum oxide (MoO _3), as to heating the intermetallic compound powder spherical core formed on the surface of the molybdenum oxide (MoO ₃₎ shell with 300 ℃ to 1200 ℃ temperature under a hydrogen atmosphere and scheme 1 and scheme 2 Reduce to molybdenum (Mo).

[Scheme 1]

MoO ₃ (s) + H ₂ (g) → MoO ₂ (s) + H ₂ O (g)

MoO ₃ (s) + 2H ₂ O (g) → MoO ₃ (OH) ₂ (g) + H ₂ (g)

MoO ₃ (OH) ₂ (g) + 2H ₂ (g) → MoO ₂ (s) + 3H ₂ O (g)

[Scheme 2]

MoO ₂ (s) + 2H ₂ (g) → Mo (s) + 2H ₂ O (g)

The second RF plasma step (S18) is a final core-shell surrounded by the molybdenum (Mo) shell by RF plasma treatment of the spherical core intermetallic powder formed on the surface of the molybdenum (Mo) nanoparticles passed through the reduction step (S17) It is a step of preparing the intermetallic compound powder of the spherical superheat-resistant alloy in the form of (core-shell).

In the second RF plasma step, the spherical core intermetallic compound powder having the molybdenum (Mo) nanoparticles formed on the surface thereof is applied to the RF plasma reaction chamber in the same manner as the first RF plasma step S14, and plasma power of 3 to 10 kW is applied. To prepare an intermetallic compound powder of the spherical superheat resistant alloy, the intermetallic compound powder of the spherical superheat resistant alloy thus prepared is shown in FIG.

Figure 3 is a photograph of the cross-section of the spherical super-alloy powder intermetallic compound prepared by the secondary RF plasma step in accordance with an embodiment of the present invention with a scanning electron microscope (Scanning Electron Microscope, SEM).

As shown in FIG. 3, an intermetallic compound powder of a spherical superalloy in the form of a core-shell is included in the core, and the molybdenum (shell) is contained in the core. Mo). The thickness of the shell (shell) formed in this way may be formed to a thickness of about 1 to 10㎛, but is not limited to this, the thickness can be adjusted as needed while controlling the amount of molybdenum oxide (MoO ₃ ).

In the method of manufacturing the intermetallic compound powder of the spherical superalloy alloy of the present invention, the core includes the intermetallic compound of the superalloy alloy, and the molybdenum (Mo) is contained in the core through two RF plasma treatment processes. It is possible to prepare a powder of intermetallic compound of spherical super heat-resistant alloy comprising a core-shell-type composite powder containing and having a spheroidization ratio of 95% or more.

Claims (11)

An alloy ingot manufacturing step of producing an intermetallic compound ingot of a super heat resistant alloy through an arc melting method;
Grinding the intermetallic compound ingot to produce a core intermetallic compound powder;
RF plasma treatment of the core intermetallic compound powder to produce a spherical core intermetallic compound powder;
Coated to form a molybdenum oxide (MoO ₃₎ in the spherical shell core intermetallic compound powder surface produced in the first plasma step;
Molybdenum oxide on the surface of the spherical core intermetallic compound powder by reducing molybdenum oxide (MoO ₃ ) to molybdenum (Mo) from the spherical core intermetallic compound powder formed on the surface of the molybdenum oxide (MoO ₃ ) shell through the coating step A reducing step of forming particles; And
Spherical core intermetallic compound of the core-shell type core super-shell alloy surrounded by molybdenum (Mo) shell by RF plasma treatment of spherical core intermetallic compound powder formed on the surface of the molybdenum (Mo) nanoparticles Secondary RF plasma step of producing a powder; spherical super-alloy powder intermetallic compound powder manufacturing method comprising a. The method of claim 1,
The alloy ingot manufacturing step,
Spherical super heat-resistant characterized in that the molybdenum (Mo), silicon (Si) and boron (B) is heated in an inert gas atmosphere to form Mo ₅ SiB ₂ phase and Mo ₃ Si phase with the intermetallic compound of the super-alloy alloy Method for preparing intermetallic powder of alloy. The method of claim 2,
The alloy ingot manufacturing step,
Method for producing an intermetallic compound powder of a spherical superalloy alloy, characterized in that to form a superalloy intermetallic compound by heating to a temperature of 1400 ℃ to 1800 ℃. The method of claim 1,
The grinding step,
The intermetallic compound powder production method of the spherical super-alloy alloy, characterized in that the ingot is ground with a grinder in an inert gas atmosphere. The method of claim 1,
Particle size of the core intermetallic compound powder pulverized in the crushing step is 1 to 100㎛ characterized in that the intermetallic compound powder production method of the spherical super-alloy alloy. The method of claim 1,
The primary RF plasma step,
Spherical super intermetallic alloy powder production of the spherical super-intermittent alloy, characterized in that to produce a spherical core intermetallic compound powder by applying a plasma power of 3 to 10kW while flowing the core intermetallic compound powder with an inert gas in the RF plasma reaction chamber Way. The method of claim 1,
The reduction step,
Oxidized molybdenum (MoO ₃₎ spherical seconds, comprising a step of the shell by heating an intermetallic compound powder spherical core formed on the surface in 300 ℃ to 1200 ℃ temperature under a hydrogen atmosphere reduced the oxidation of molybdenum (MoO ₃₎ with a molybdenum (Mo) Method for producing intermetallic compound powder of heat resistant alloy. The method of claim 1,
The secondary RF plasma step,
The spherical core intermetallic compound powder formed on the surface of the molybdenum (Mo) nanoparticles are put in an RF plasma reaction chamber to apply a plasma power of 3 to 10kW to produce a spherical superalloy powder of the spherical super alloy Method for preparing intermetallic compound powder of super heat resistant alloy. The method of claim 1,
And a classification step of classifying the pulverized core superalloy powder intermetallic compound powder after the grinding step and before the first RF plasma step. An intermetallic compound powder of a spherical superheat resistant alloy in the form of a core-shell manufactured by the method according to any one of claims 1 to 9, wherein the core includes an intermetallic compound of a super heat resistant alloy. And, the shell (mol) contains molybdenum (Mo) spherical superalloy powder of superalloy alloy. The method of claim 10,
It said second heat-resistant alloy of the intermetallic compound is ₅ SiB Mo ₂ Mo ₃ Si and the merchant spherical second intermetallic compound of a heat-resistant alloy powder, characterized in that.

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