JPS6046305A - Alloy powder manufacturing process and device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Background of the Invention 1) Field of the Invention The present invention relates to the production of alloy I) powder.
To be more specific, the reduction of impurity Venus is 1-! f sign and 1
Concerned with the production of superalloy powder.

2) Description of the Prior Art Various alloy powder production/methods and equipment are known in the metallurgical industry. For example, Fe, Co, NL, T
When it comes to heat-resistant alloys and superalloys that use ＋ or combinations thereof as base materials, current powder manufacturing methods first involve the use of vacuum electron beam heating, vacuum arc heating, vacuum induction heating, or vacuum plasma heating techniques. By melting the alloy components in a high vacuum furnace chamber, ingots 1 to 1 are manufactured. After manufacturing the alloy ingot, the current powder manufacturing method involves using a ceramic hearth for primary melting along with a ceramic pot and nozzle to obtain the molten metal flow necessary for powder manufacturing, followed by gas atomization. The alloy is injected by methods such as rotary atomization, rotary atomization, or vacuum atomization.
is powdered.

In the case of gas turbine engines, powdered metals are used in the manufacture of certain components (eg, turbine disks) that operate under high temperatures and stresses.

Manufacturing costs can be reduced by producing powder metal preforms that approximately match the final shape of the target part. However, if the cleanliness of the powdered metal is insufficient, especially if it originates from ceramic particles introduced into the currently used powder manufacturing method, low cycle fatigue may occur in the finished part. It has been recognized that a significant decrease in mechanical properties can occur. Such a reduction is due to the presence of defects in the combined powder metal disc that act as initiation sites for low cycle fatigue failure. - It is caused by doing. The 7th and all superalloy powder metals for use in
It is manufactured according to the procedure of preparing ~, melting the ingot, and then converting it to a gas atomization method. Such spraying methods involve the expense of lamic melting and extraction equipment, which is undesirable and introduces a significant proportion of ramic inclusions. It has been found that the present invention is advantageous in that the starting bit can be Ishikawa in 1:f if it contains almost no ramic inclusions.

Summary of the Invention The main object of the present invention is to develop an improved alloy TJ powder in which the Ml solution is carried out without contact with the reramic part and the powder is produced directly from the molten gold. The purpose of the present invention is to provide a method for producing a newspaper.

It is also one of the objects of the present invention to provide an improved apparatus for producing alloy powders through the use of means for melting the metal material of the alloy without contact with the ceramic component.

The above and other objects and advantages will be more clearly understood from the following detailed description of the preferred embodiment and the accompanying drawings. The following description and drawings are intended to illustrate the implementation of the present invention, and are not intended to limit the scope of the present invention in any way.

Briefly described in accordance with one aspect of the method of the present invention, a melting hearth with liquid-cooled walls is provided and a metallurgy defining the alloy composition is placed therein. The metal material is then melted in the hearth. According to one particular embodiment, melting of the metallic material is achieved by directing a plasma heat source at the metal shrine and the hearth to provide substantially uniform heat to the metallic material. is started and executed.

During melting, sufficient cooling liquid is supplied into the hearth walls to resolidify the molten metal material adjacent the cold hearth walls. As a result, a hearth shell made of metal is formed along one wall of the hearth, and the excess molten alloy is kept inside the hearth shell. 'd fA'i! It will be maintained as an alloy reservoir. The excess molten alloy is then drained from the hearth into a powder metal maker.

One aspect of the apparatus of the present invention includes a liquid-cooled hearth for collecting metal (IA) and a liquid-cooled hearth for discharging the metal (IA) and a liquid-cooled hearth for dissolving the metal monthly rate in the hearth by 81 (+1) to avoid generating a molten alloy puddle. A metal material product consisting of a heat source, powder gold I11,
And melt f11! A means for introducing molten 811 alloy from an alloy reservoir into a powder metal production device is provided. According to one embodiment, the metal + A stone melting means described in -1 is a movable Zolazun heat d disposed toward the hearth.
Including fA, the entire surface area of the metal material in the hearth is I, +l.
(J・I J provides substantially uniform heat to the metal material.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The development of modern aircraft gas turbine engines has created a need for high temperature operating materials that can withstand greater stresses at higher temperatures. On the other hand, the complexity of part design and advances in powder metallurgy processing and alloy formulation make the use of powdered metals attractive from an economic manufacturing standpoint. Additionally, the use of powdered metals also allows the desirable properties of low cycle fatigue resistance to be achieved along with high temperature operating characteristics.

A typical example of a component that requires extreme strength and high heat resistance is the rotating disk used in the turbine section of the latest gas turbine engine.

Sometimes other engine parts are used in the compressor section, for example made of T+ based alloys. However, it has been recognized that in order to achieve desirable low cycle fatigue properties, certain impurities must be excluded from the powdered metal used in such processing.

It is known that the main impurity responsible for the defects in the disks described above is ceramic, whose origin lies in the processing steps necessary to produce the powder from the initial starting materials or alloys. The presence of such defects can reduce the low cycle fatigue properties of the disc below the levels required under high temperature and high stress conditions.

For example, ceramic melting and pouring devices are used in the d5 atomization process for producing powdered metals from superalloys made of wood, such as Fe, Co, NL or combinations thereof. . Such ceramic structures contain a considerable proportion of ceramic impurities.
In finished parts manufactured by powder metallurgy techniques, the impurities often constitute defects that act as initiation sites for low cycle fatigue failure.

According to J3 of the present invention, contact between the lemmic member and the powder manufacturing alloy is achieved by melting the metal molten metal without contact with the ceramic member and then introducing the resulting molten alloy into a powder metal manufacturing machine. Avoided. According to one embodiment, a liquid-cooled melting hearth and a movable or otherwise This is achieved in conjunction with a good plasma heat source. The liquid-cooled hearth provides resolidification of molten metal material within the hearth adjacent the walls of the hearth. As a result, a hearth shell of metallic material is formed as a barrier between the hearth material and the molten alloy remaining therein.

By using a movable plasma heat source, such as one or more movable plasma heat sources, rapid and uniform heating and melting of the material defining the composition of the alloy to be pulverized is achieved. Moreover, the use of a movable primary plasma heat source with a 1+J capability of sweeping the entire surface of the metal material in the hearth provides a sufficiently practical temperature for 9 people to enter the powder metal production machine. It also becomes easier to overheat the molten alloy up to

One embodiment of the present invention between stations is shown in the accompanying drawings. An improved means for melting the metal material within the melting chamber 10 includes a liquid cooled hearth 12. hearth 12
A cooling fluid passageway 14 is located within the wall 13 and is connected to a source of cooling fluid, such as water (not shown). d3. The term "wall" as used herein may include not only the side walls but also the bottom of the member in question, if desired.

The melting process 10 can be accomplished by introducing an inert gas, for example argon, through the gas outlet 16 to establish the desired atmosphere or pressure conditions, or by exhausting it through the gas outlet 18. be. It will be obvious to those skilled in the art that, depending on the various methods currently in use, other suitable means can be used to adjust the atmosphere in the antechamber 10.Hearth 12 Disposed above the hearth 12 is a plasma heat source 20, illustrated as comprising a plurality of plasma torches, which may be movable. After introducing the metal material 22 into the hearth 12,
The plasma heat source 20 can be used to initiate and progress the melting of the metal material. In the case of a movable type, by sweeping the entire surface of the metal material with the plasma heat source 20,
Substantially uniform heat can be supplied to the metal material.

In operation of the improved melting means described above, a metal material 22 defining the alloy composition is placed within the hearth 12. Such introduction may be carried out in a batch manner or alternatively in a continuous or semi-continuous manner using auxiliary metal feeding equipment of a type well known in the art. For example, a chute feed mechanism of the type described in Bomberger, Jr. et al., U.S. Pat. The contents of this patent specification are incorporated into the present specification by reference.

While a coolant such as water is circulated within the coolant passage 14, a plasma heat source 20 consisting of, for example, one dark blue movable plasma 1--2 is activated. According to this embodiment, the metal material is dissected by moving the torch and sweeping the entire surface of the metal material 22 in the -C hearth 12.

When the molten metal material contacts the cooled inner walls of the hearth 12, it resolidifies to form the hearth shell 24, and the molten metal material is maintained within the hearth walls and the hearth. The extra molten alloy will act as a buffer layer. In this way, hearth material is prevented from contaminating the molten alloy in the hearth, thus providing a molten alloy puddle that is substantially free of foreign matter.

After the desired degree of melting and superheating) has been achieved, arrow 2
As shown by 8, the hearth 12 can be traced around pivots 1-2G by the use of tilting means or structures (
σI slope U is given. The molten PAgt alloy remaining within the hearth 12 after formation of the hearth shell 24 during resolidification is preferably drained or poured 441 out of the hearth 12 from the hearth lip 30, thereby melting the PAgt alloy. The alloy stream 32 is 1rt. In the illustrated case, according to one embodiment of the invention -C
, the molten alloy stream 32 is poured into a metal flow control iWi neck consisting of a liquid-cooled weir track 34 that serves an auxiliary handling purpose. However, the molten alloy stream 32 may be introduced into any of a variety of other metal flow conditioning devices known to those skilled in the art, or may necessarily be introduced into the powder metal production apparatus. Of course, it is also possible to introduce directly.

In the illustrated embodiment of the invention J'3, the molten metal stream 32 is introduced into a metal flow conditioning device consisting of a liquid-cooled weir track 34. The weir site 34 is provided with a coolant passage 36 and is connected to a source of coolant (not shown), such as water, by methods well known in the art.

Like the hearth 12, the weir track 34 can also include a weir track lip 38 to facilitate the flow of molten alloy.

In operation, weir track 34 receives molten alloy supplied from hearth 12 as molten metal stream 32 while circulating cold Nl liquid in coolant passage 36 . When the molten alloy comes into contact with the cooled wall of the weir bowl 34, a portion of the molten alloy solidifies to form a weir trace shell 40 similar to the hearth shell 34. The I1g pot shell 40 will similarly act as a barrier or buffer layer between the walls of the weir scar and any excess molten alloy retained within the weir scar after formation of the weir scar shell. In order to maintain the excess molten alloy existing in the weir ruins in a molten state, for example, plasma 1 to -
A secondary plasma heat source consisting of 42h1 may be required.

In operation, secondary plasma heat 842 is directed toward excess molten alloy remaining within the weir scar 34 after formation of the weir scar shell 40 upon resolidification. Finally, molten alloy stream 44 flows from weir track 34 into powder metal maker 46 .

Such powder metal production equipment may be of various types well known in the art, such as spray type equipment for powder metal production, and other crushing type equipment.

What is schematically shown in the drawing is a gas spray type device i/7-
(There is. This device is a cold IJ that melts molten metal.
Contains JI 'F'+48, molten metal population i) 0
The surrounding area of the molten alloy through which it enters the cold column 48? In the /1t44, a spraying means 52 for spraying a fog gas is arranged to spray an 11-membered 6-carbon gas such as rugon, nitrogen, helium, etc.

The atomizing gas is 1111 pressure gas (not shown).
(Feeded through pipe 54, the atomizing gas dispersed into the molten alloy stream disperses the molten alloy stream into small particles.) The particles solidify and are deposited at the bottom of the cooling JJI column 48. falls and accumulates in the powder metal collector 56. As shown in the drawings, it is advantageous to install an exhaust system 58 with such powder metal manufacturing equipment. Generally speaking, the exhaust system 58 includes a cyclone type collector 60, such as is well known in the art.

Within the melting chamber 10 there may be provided, for example, a hearth lip 3.
An auxiliary heat source placed opposite one or both of the dam lip 38 and the dam lip 38 can be used.

This makes it easier to dispense the molten alloy streams 32 and 44 at the desired molten or superheated state.

To give an example of the evaluation of the improved 811 melting chamber or metal 4A melting means of the present invention, 0.06 (weight)% C113 (heavy use) Cr, 8 (weight 1=ij)% G
13.5 (heavy)% cold, 3.5 (wt)% Cb, 0
．． 05 (m M!)% Zr, 2.5 (ifj2)
%T2.3.5 (weight)%/V, 0. (11 (heavy use)% B13.5 (heavy use)% W J5 and the remainder NL
and incidental impurities.
A nickel-based superalloy commercially available as nc) 95 was used. In this evaluation example, three plasmas constituting the -order plasma heat source 20 were concentrated on a water-cooled copper melting hearth 12. Further, as shown in the drawings, the part 11 of A) that constitutes the secondary plasma heating wire 42.

Lasma 1 Hage was concentrated in a water-cooled copper Ede-use pot 34. d3, in the hearth 12 (of f, j!! solution) In another evaluation example, there are fewer than 3 pieces, so 1
I also use a laser torch. -Next plasma source ((
The plasma stage for heating the hearth is movable in 63 directions orthogonal to the 17'J, 17'J, 17' plasma for heating the clothing that constitutes the plasma stage for heating the hearth. 1 h-
I move vertically and horizontally (movement I'iJ
It was fiiii. Side of device and braz-/1・-
The supporting body of C is protected by a heat insulating material.
＞　(Moyoi Plasma 1 and 471 rivers, Ishi-(According to history I'Re!', metal flow adjustment device and C weir ruins as silk) (If used, defective part It has now been found that an improved means for melting metallic materials is provided which is useful for producing alloy powders without a substantial increase in ceramic impurities, which can affect carbon.

By using the device of the present invention, especially Fe, Co, NL-T+
An improved method for producing an alloy powder made of a heat-resistant alloy or a superalloy based on a heat-resistant alloy or a combination thereof is obtained.

This method is characterized in that an increase in ceramic impurities leading to defects is substantially avoided.

The present invention has been described above with reference to specific embodiments.
ζ. However, those skilled in the art will readily understand that various modifications and changes can be made without departing from the scope of the invention as defined in the claims.

[Brief explanation of the drawing]

The drawing is a schematic partial cross-sectional view C showing one embodiment of the apparatus of the present invention including an improved melting chamber and powder metal production apparatus. In the figure, 10 is fused Fl? 12 is the hearth, 13 is the wall of the hearth, 14 is a coolant passage, 16 is a waste inlet, 18 is a waste outlet]
'', 20 is a primary plasma heat source, 22 is a metal filler, 24 is a hearth shell, 26 is a pivot, 30 is a hearth lip, 32 is a molten metal flow, 34 is a weir trace, 36 is a coolant passage, 38 is a Weir ruin lip, 40 is weir ruin outer shell, 42 is secondary plasma heat source,
44 is the molten alloy flow, 46 is the powder metal manufacturing equipment, 48 is the cooling tower, and 50 is the molten metal 8g! 52 is a means for spraying atomizer 1), 50 is a powder metal collector, 58 is an exhaust device,
And 60 does not represent a dust collector. patent applicant

Claims (1)

[Claims] 1. (A> A metal material that defines an alloy composition is placed in a melting hearth, and (B) a plasma heat source is used to melt the metal material in the hearth. simultaneously forming an alloy and forming a hearth shell of resolidified metal material between the molten alloy and the hearth, and then (C) transporting the molten alloy from the hearth into a powder metal manufacturing machine; 2. (A) preparing a melting hearth having a liquid-cooled wall; (B) introducing a metal material that defines the alloy composition; (C) operating a plasma heat source toward the metal material in the hearth to melt the metal material;
supplying sufficient cooling liquid into the walls of the hearth to resolidify the IC molten metal material adjacent to the walls of the hearth; At the same time, the excess molten alloy present in the hearth outer shell is maintained as a molten alloy reservoir, and then (D> the excess molten alloy is 3. A method for producing an alloy powder, characterized in that it comprises the following steps: 3. The plasma heat source covers the entire surface of the metal 4Δ stone.
2. The method of claim 2IQ, wherein substantially uniform heat is provided to the metallurgy by irradiation. 4. The method of claim 2, wherein the excess molten alloy is introduced into the powder metal production machine via a metal stream. In the method d1 described in the preceding paragraph in which the storage pot is used as the metal flow control device, while the excess molten metal is poured into the storage pot from the hearth, the Ic Excess molten metal, 41; a container consisting of a portion of the excess molten alloy is placed inside the container by supplying sufficient cold 7JI d into the walls of the garment to re-solidify the alloy. The method according to claim 4, comprising the steps of forming a pot outer shell and then pouring excess molten alloy from the pot into the powder metal manufacturing device.6. 7. A method according to claim 51, in which the secondary plasma heat source is operated toward the excess molten alloy within the weir. 7. The method of claim 6, wherein substantially uniform heat is provided to the excess molten alloy by sweeping. 8. An alloy powder comprising means for producing powder from the molten alloy. In the production apparatus: (a) a liquid-cooled Ic hearth for housing a metallurgical metallurgy 1 over a defined alloy composition and for FAL analysis of said metallurgical metallurgy to produce 'CmCm pre-state gold'; (b) a plasma heat source disposed toward the hearth and for melting the metal to produce molten alloy; and (C) means for introducing the molten alloy into a powder metal production apparatus. An apparatus for producing alloy powder characterized by: 9. During operation, the plasma heat supplies substantially uniform heat to each of the metal parts by sweeping the surface of each of the metal parts in the hearth ?l≦1 1. an IC for receiving an alloy and discharging at least a portion of the molten alloy from the molten alloy; 10. The apparatus according to claim 8, further comprising: a liquid-cooled weir trace arranged in said means for producing a powder; 1) The apparatus according to claim 101i'1, which includes a secondary Zolazin heat source that keeps the molten alloy in the weir bowl in a molten state.