KR102432708B1 - Method for manufacturing molybdenum copper sintered alloy - Google Patents

Abstract

The present disclosure provides a method comprising the steps of: (a) forming a copper-containing saturated solution; (b) blending the solution of step (a) with the molybdenum-containing powder; (c) roasting and reducing the formulation; (d) press-molding the powder obtained in step (c); and (e) sintering the compact obtained in step (d).

Description

Molybdenum-copper sintered alloy manufacturing method {METHOD FOR MANUFACTURING MOLYBDENUM COPPER SINTERED ALLOY}

The present invention relates to a method for manufacturing a molybdenum-copper sintered alloy, and more particularly, by using a composite powder material containing molybdenum (Mo) and copper (Cu), it has excellent adhesion, alloy composition and texture uniformity of molybdenum and copper. And, it relates to a method of manufacturing a molybdenum-copper sintered alloy with improved physicochemical performance.

Molybdenum-copper (Mo-Cu) alloy has high strength, has excellent thermal and electrical conductivity, and has the characteristics of being able to control the coefficient of thermal expansion according to the Cu content. Mo-Cu alloys with these characteristics are currently being actively studied in various application fields such as heat dissipation materials, semiconductor parts, and automobile parts.

However, despite having such excellent properties and applications, Mo and Cu have very few solid solution sections in the liquid and solid phases, so it is very difficult to alloy Mo and Cu with each other. Currently, as a method of manufacturing a Mo-Cu alloy, there are spray drying, injection molding, electroless plating, etc., but these methods have a complex process, and the manufactured Mo-Cu alloy Since the composition and the uniformity of the structure of the alloy are inferior, it is a factor that reduces the excellent thermal and electrical conductivity of the Mo-Cu alloy.

A method of mixing molybdenum powder and copper powder and sintering the blended powder is used as a method of manufacturing a Mo-Cu alloy that has been put into practical use. At this time, since the adhesion between the molybdenum powder and the copper powder is not good, there is a problem in that the physicochemical performance of the finally formed molybdenum-copper alloy is deteriorated. In order to solve this problem, a method of improving adhesion by adding a metal element such as nickel (Ni) or cobalt (Co) has been proposed. However, when a molybdenum-copper alloy is manufactured by adding an additional metal element as described above, the physicochemical properties of the added metal element affect the quality of the molybdenum-copper alloy, so that the required quality and performance cannot be met. did.

Patent Document 1 (Republic of Korea Patent No. 10-0762664) includes individual finite particles each having a copper phase and a molybdenum phase, each finite particle has a sintered molybdenum network, and the pores in the sintered network are filled with copper to form a molybdenum phase. Molybdenum-copper composite powder encapsulating copper phase, and (a) reducing CuMoO ₄ -based composite oxide powder in the first step to obtain a homogeneous mixture of metallic copper oxide and molybdenum oxide without formation of a low-melting cuprous molybdate phase forming; and (b) reducing the homogeneous mixture in the second step at a temperature and for a time sufficient to reduce molybdenum oxide to molybdenum metal. It is disclosed that a Mo-Cu pseudoalloy can be produced by consolidation and sintering by the powder metallurgy technology of

Patent Document 2 (Republic of Korea Patent Publication No. 10-2019-0063472) is a step of pressing a base powder metal mixture containing at least one of Mo and W; impregnating the base powder metal mixture into the Cu-enriched phase; and sintering the impregnated base powder metal mixture.

Patent Document 1: Republic of Korea Patent Registration No. 10-0762664 (2007.09.20.) Patent Document 2: Republic of Korea Patent Publication No. 10-2019-0063472 (2019.06.07.)

The problem to be solved by the present invention is that, by using a fine molybdenum (Mo) and copper (Cu) composite powder material, the adhesion between molybdenum and copper, the alloy composition and the uniformity of the structure are excellent, and the molybdenum with excellent physical and chemical performance is further improved. - To provide a method for manufacturing a copper sintered alloy.

One embodiment of the present invention for solving the above problems provides a method for producing a molybdenum-copper sintered alloy, the method comprising the steps of: (a) forming a copper-containing saturated solution; (b) blending the solution of step (a) with the molybdenum-containing powder; (c) roasting and reducing the formulation; (d) press-molding the powder obtained in step (c); and (e) sintering the molded body obtained in step (d).

In the embodiment, the saturated solution may include cupric chloride (CuCl ₂ ), copper sulfate (CuSO ₄ ), or a combination thereof.

The saturated solution may include a solvent selected from methanol, acetone, normal hexane, and combinations thereof.

The molybdenum-containing powder may include molybdenum (Mo) powder, molybdenum trioxide (MoO ₃ ) powder, or a combination thereof.

The roasting of step (c) may include heating to a temperature in the range of 150 to 900° C. in an electric furnace under a hydrogen atmosphere, and the reduction is heated to a temperature in the range of 600 to 1,000° C. in an electric furnace under a hydrogen atmosphere. may include doing

Between step (c) and step (d), (f) may further include the step of blending the additive to the powder obtained in step (c).

The additive is selected from the group consisting of polyethylene glycol (PEG), polyvinyl butyral (PVB), stearate, methanol, normal hexane, and combinations thereof. can be

Between the steps (c) and (d), the step of (g) granulating may be further included.

Between the steps (d) and (e), (h) under a hydrogen atmosphere, heating to a temperature in the range of 30 ~ 900 ℃ in an electric furnace may further include a degreasing step of removing organic matter.

The step (d) may be made under a pressure in the range of 10 ~ 3,000 kg / ㎤.

The step (e) may be made at a temperature in the range of 700 to 1,700° C. in an electric furnace under a hydrogen atmosphere.

The molybdenum-copper sintered alloy prepared by the manufacturing method may include 0.1 to 99 wt% of molybdenum and 0.1 to 99 wt% of copper.

According to an embodiment of the present invention, by using a composite powder material containing molybdenum (Mo) and copper (Cu), it is possible to prepare a Mo-Cu sintered alloy with excellent adhesion between molybdenum and copper and with improved physicochemical performance. can

In addition, according to an embodiment of the present invention, it is possible to efficiently and economically manufacture a Mo-Cu sintered alloy having excellent alloy composition and texture uniformity by a more easy and simple process.

Since the Mo-Cu alloy prepared according to an embodiment of the present invention exhibits excellent physical and chemical performance such as excellent thermal conductivity and electrical conductivity, it can be widely applied to various application fields such as heat dissipation materials, semiconductor parts, and automobile parts.

1 is a process flow diagram showing a method of manufacturing a Mo-Cu sintered alloy according to an embodiment of the present invention.
2 is a photograph of a Mo-Cu sintered alloy prepared according to an embodiment of the present invention.

Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings in order to describe in detail enough that a person of ordinary skill in the art to which the present invention pertains can easily implement the technical idea of the present invention. In the following description, many specific details such as specific components are shown, which are provided to help a more general understanding of the present invention, and it is common knowledge in the art that the present invention may be practiced without these specific details. It will be self-evident to those who have And, in describing the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

One embodiment of the present invention comprises the steps of: (a) forming a copper-containing saturated solution; (b) blending the solution of step (a) with the molybdenum-containing powder; (c) roasting and reducing the formulation; (d) press-molding the powder obtained in step (c); and (e) sintering the compact obtained in step (d).

According to the method of manufacturing a Mo-Cu sintered alloy according to an embodiment of the present invention, compared to the method of manufacturing a Mo-Cu sintered alloy by mixing the conventional molybdenum powder and copper powder, press-molding and sintering it, molybdenum and copper By improving the adhesion between them, the physicochemical performance of the sintered alloy can be further improved.

Hereinafter, with reference to FIG. 1, a method of manufacturing a Mo-Cu sintered alloy according to an embodiment of the present invention will be described in detail.

1 is a process flow diagram showing a method of manufacturing a Mo-Cu sintered alloy according to an embodiment of the present invention.

Referring to FIG. 1 , in step (a), a copper-containing saturated solution serving as a source of copper of the Mo—Cu sintered alloy may be formed.

In an embodiment, the copper compound contained in the copper-containing saturated solution may include cupric chloride (CuCl ₂ ), copper sulfate (CuSO ₄ ), or a combination thereof. In consideration of the compatibility with the molybdenum-containing powder and the physicochemical properties of the final Mo-Cu sintered alloy, cupric chloride and/or copper sulfate may be preferably used as the copper source.

In one embodiment, the solvent contained in the copper-containing saturated solution may be selected from methanol, acetone, normal hexane, and combinations thereof.

The mixing ratio of the solvent and the copper compound may be selected to form a saturated solution in consideration of the solubility of the copper compound.

In step (b), the solution of step (a) may be blended with the molybdenum-containing powder.

In this embodiment, the molybdenum-containing powder may be used as the molybdenum source of the Mo-Cu sintered alloy.

The molybdenum-containing powder may include molybdenum (Mo) powder, molybdenum trioxide (MoO ₃ ) powder, or a combination thereof.

Molybdenum trioxide (MoO ₃ ) is a colorless crystalline powder, and is very stable in air.

Considering the compatibility with the copper compound included in the copper-containing saturated solution of step (a) and the physicochemical properties of the final product, Mo-Cu sintered alloy, molybdenum (Mo) powder and/or molybdenum trioxide ( MoO ₃ ) powder may be preferably used.

The mixing ratio of the copper-containing saturated solution and the molybdenum-containing powder may be determined according to the composition of the Mo-Cu sintered alloy to be finally prepared.

In one embodiment, the Mo-Cu sintered alloy may comprise 0.1-99 wt % molybdenum and 0.1-99 wt % copper, preferably 1-90 wt % molybdenum and 1-90 wt % copper .

In one embodiment, in step (b), an additional metal powder may be further blended into the blend of the molybdenum-containing powder and the solution of step (a).

The additional metal powder may serve to increase the thermal and electrical conductivity of the Mo-Cu sintered alloy, and to improve physical properties such as wear resistance.

The additional metal powder that may be formulated may be selected from the group consisting of gold (Au), silver (Ag), nickel (Ni), cobalt (Co), tin (Sn), iron (Fe), and combinations thereof.

The content of the additional metal powder may be 0.1 to 3 wt% based on the total weight of the Mo-Cu sintered alloy. If the content of the additional metal powder is less than the above range, the effect of improving the physical properties of the Mo-Cu sintered alloy obtained by using the additional metal powder is insufficient, and when it exceeds the above range, further improvement of the effect due to the increase in the content is expected It is difficult to do, and on the contrary, it may negatively affect the physical properties of the Mo-Cu sintered alloy.

In step (c), the mixed powder in which the molybdenum-containing powder and the copper-containing saturated solution are blended may be roasted and reduced.

Roasting refers to a process in which a solid sample such as ore is heated at a temperature below its melting point to change its chemical composition and physical properties.

Reduction can be referred to collectively as a reaction to remove oxygen or gain electrons.

In this embodiment, the roasting may include heating to a temperature in the range of 150 ~ 900 ℃ in an electric furnace under a hydrogen atmosphere.

In this embodiment, the reduction may include heating to a temperature in the range of 600 ~ 1,000 ℃ in an electric furnace under a hydrogen atmosphere.

In one embodiment, roasting and reduction may be accomplished by heating in the above temperature range for 5 to 15 hours.

Optionally, in step (f), additives may be blended into the powder obtained in step (c).

Additives may be selectively added to improve the physicochemical properties of the Mo-Cu sintered alloy.

In one embodiment, polyethylene glycol (PEG), polyvinyl butyral (polyvinyl butyral, PVB), stearate (stearate), methanol (methanol), normal hexane (normal hexane), and a combination thereof group can be selected.

The content of the additive may be 0.01 to 20 wt% based on the total weight of the Mo-Cu sintered alloy. When the content of the additive is less than the above range, it is difficult to sufficiently exhibit the effect of improving the physicochemical properties of the Mo-Cu sintered alloy according to the addition of the additive. , rather it can negatively affect the physicochemical properties of the Mo-Cu sintered alloy.

The mixing of the additive may be accomplished by adding the additive to the powder obtained in step (c) and mixing for 5 to 15 hours using a mixer, for example, a planetary mixer.

Optionally, in step (g), the formulation may be granulated.

Granulation refers to the process of forming particles or granules from a powder or solid material. Typically granulation may involve agglomeration of fine particles into larger granules.

In this embodiment, granulation improves the flowability by controlling the surface state of the powder, so that it can fill the inside of the mold within a short time in the subsequent pressure molding step, thereby increasing the molding speed, and enabling uniform filling, resulting in defects inside the molded body. may play a role in reducing the incidence.

The size of the granules obtained by the granulation of step (g) may be in the range of 1 to 100 mesh (mesh). If the size of the granules is less than the above range, the effect of improving the flowability by granulation may be insufficient, and if it exceeds the above range, uniform filling is not made in the subsequent pressure molding process, and defects may occur inside the molded body. .

In step (d), the powder or granular formulation may be press-molded.

Press molding may be performed by filling a mold with a compound according to the shape of a desired molded object, and then applying pressure using a press.

Press molding may be made under a pressure in the range of 10 ~ 3,000 kg / cm 3 . When the pressure is out of the above range during press molding, the molded body may not be properly formed or defects may occur.

Optionally, in step (h), a degreasing step may be further included.

The degreasing step is for removing organic matter contained in the molded body. For example, when PEG, PVB, etc. are used as additives, a degreasing step may be performed to remove these organic materials before the sintering process.

In one embodiment, the degreasing step may be performed by heating to a temperature in the range of 30 ~ 900 ℃ in an electric furnace under a hydrogen atmosphere.

In step (e), a Mo-Cu sintered alloy may be formed by sintering the compact.

In one embodiment, the sintering may be performed at a temperature in the range of 700 to 1,700 ° C., preferably in the range of about 1,000 to 1,200 ° C. in an electric furnace under a hydrogen atmosphere. If the sintering temperature is out of the above range, sintering may be insufficiently made or defects may occur, and the physical properties of the sintered alloy may be reduced.

The sintering time may vary depending on the sintering temperature, for example, may be 3 to 20 hours.

The Mo-Cu sintered alloy manufactured according to this embodiment has excellent adhesion to molybdenum and copper, alloy composition and uniformity of structure, and can exhibit further improved physicochemical performance. Therefore, since this Mo-Cu alloy exhibits excellent physical and chemical performance such as excellent thermal and electrical conductivity, it can be widely applied to various applications such as heat dissipation materials, semiconductor parts, and automobile parts.

In addition, according to an embodiment of the present invention, the Mo-Cu sintered alloy can be efficiently and economically manufactured by a more easy and convenient process.

Hereinafter, the present invention will be described in more detail by way of Examples. However, the following examples are merely illustrative of the present invention, and the scope of the present invention is not limited to the following examples.

[Example]

1. Preparation of Mo-Cu sintered alloy

Copper chloride (CuCl ₂ ) was dissolved in 5,000 cc of methanol in a saturated state to form a saturated solution. Molybdenum trioxide (MoO ₃ ) powder was added to the saturated solution and blended. Table 1 below shows the raw material blending amount according to the Mo-Cu alloy composition ratio.

Mo-Cu alloy composition ratio (Mo:Cu) MoO ₃ mixing amount (kg) CuCl ₂ blending amount (Kg) 100 : 0 15.00 0.00 90:10 13.50 2.12 80:20 12.00 4.23 70:30 10.50 6.35 60:40 9.00 8.46 50:50 7.50 10.58 40:60 6.00 12.69 30:70 4.50 14.81 20:80 3.00 16.93 10:90 1.50 19.04 0 : 100 0.00 21.16

The blended powder was roasted by heating at 150-900°C for 10 hours in an electric furnace under a hydrogen atmosphere, and reduction was performed at 600-1,000°C. In a planetary mixer, the obtained composite powder, 0.08 kg of polyethylene glycol (PEG) and 0.08 kg of polyvinyl butyral were blended for 10 hours, and then granulated to a size of 80 mesh. Then, it was filled in a mold and pressed at 1,000 kg/cm 3 in a 30-ton press to obtain a molded article of 5T × 15W × 30L (mm). Then, under a hydrogen atmosphere, organic materials such as PEG and PVB were removed by slowly heating to 30 ~ 650 °C in an electric furnace, and then the temperature was gradually increased to 1,050 °C again, followed by sintering for 6 hours.

Thereby, a Mo-Cu sintered alloy was manufactured. A photograph of the prepared Mo-Cu sintered alloy is shown in FIG. 2 .

2. Evaluation of physical properties of Mo-Cu sintered alloy

In the same manner as in 1., the Mo/Cu content is 85 wt%/15 wt%, 80 wt%/20 wt%, 70 wt%/30 wt%, 60 wt%/40 wt%, 50 wt%/ A 50 wt% specimen was prepared, and the coefficient of thermal expansion and thermal conductivity were measured according to the following conditions.

- coefficient of thermal expansion

(1) Sample size: 5 × 5 × 5 (mm)

(2) T ₀ (Initial Temperature condition): 20℃

(3) Measurement Temperature Range: 20~300℃

- thermal conductivity

(1) Sample size: 10 × 10 × 2 (mm)

(2) Room Temperature: 25℃

(3) Measurement Temperature point: 25℃, 150℃, 175℃

The measurement results are shown in Table 2 below, and the coefficient of thermal expansion and thermal conductivity of the conventional products are shown in Table 3 for comparison.

Alloy composition (Mo/Cu) Density (g/cm3) Thermal conductivity (W/m K, 25℃) Coefficient of thermal expansion (10 ^-6 /℃) 85 wt%/15 wt% 10.06 198 6.8 80 wt%/20 wt% 9.98 210 7.3 70 wt%/30 wt% 9.85 216 7.5 60 wt%/40 wt% 9.71 228 8.7 50 wt%/50 wt% 9.57 237 9.8

Alloy composition (Mo/Cu) Density (g/cm3) Thermal conductivity (W/m K, 25℃) Coefficient of thermal expansion (10 ^-6 /℃) 85 wt%/15 wt% 10.1 195 7.0 80 wt%/20 wt% 9.96 204 7.6 70 wt%/30 wt% 9.75 208 8.0 60 wt%/40 wt% 9.62 223 9.3 50 wt%/50 wt% 9.51 230 10.3

From Tables 2 and 3, it can be seen that the Mo-Cu alloy manufactured by the manufacturing method of an embodiment of the present invention exhibits superior performance compared to the conventional Mo-Cu alloy product in terms of thermal conductivity and thermal expansion coefficient.

Therefore, according to an embodiment of the present invention, it is possible to manufacture a Mo-Cu sintered alloy having excellent adhesion, alloy composition and tissue uniformity of molybdenum and copper, and further improved physicochemical performance. The Mo-Cu alloy manufactured according to such a manufacturing method exhibits excellent physical and chemical performance such as excellent thermal and electrical conductivity, and thus can be widely applied to various applications such as heat dissipation materials, semiconductor parts, and automobile parts.

The present invention is not limited by the above-described embodiments and the accompanying drawings, and it is common in the technical field to which the present invention pertains that various substitutions, modifications and changes are possible within the scope without departing from the technical spirit of the present invention. It will be clear to those who have knowledge.

Claims (12)

(a) forming a copper-containing saturated solution comprising a solvent selected from methanol, acetone, normal hexane, and combinations thereof;
(b) blending the solution of step (a) with the molybdenum-containing powder, and gold (Au), silver (Ag), nickel (Ni), cobalt (Co), tin (Sn), iron (Fe) in this blend and 0.1 to 3 wt% of an additional metal powder selected from the group consisting of a combination thereof, based on the total weight of the Mo-Cu sintered alloy;
(c) the mixture is heated to a temperature in the range of 150 to 900 ° C in an electric furnace under a hydrogen atmosphere and roasted to cause a change in chemical composition and physical properties reducing by heating with a furnace;
(d) press-molding the powder obtained in step (c); and
(e) comprising the step of sintering the molded body obtained in step (d),
The molybdenum-containing powder includes molybdenum (Mo) powder, molybdenum trioxide (MoO ₃ ) powder, or a combination thereof
A method for producing a molybdenum-copper sintered alloy.
According to claim 1,
The saturated solution includes cupric chloride (CuCl ₂ ), copper sulfate (CuSO ₄ ), or a combination thereof.
A method for producing a molybdenum-copper sintered alloy.
According to claim 1,
Between step (c) and step (d),
(f) further comprising the step of blending an additive to the powder obtained in step (c)
A method for producing a molybdenum-copper sintered alloy.
4. The method of claim 3,
The additive is selected from the group consisting of polyethylene glycol (PEG), polyvinyl butyral (PVB), stearate, methanol, normal hexane, and combinations thereof. felled
A method for producing a molybdenum-copper sintered alloy.
According to claim 1,
Between step (c) and step (d),
(g) further comprising the step of granulating
A method for producing a molybdenum-copper sintered alloy.
According to claim 1,
Between step (d) and step (e),
(h) under a hydrogen atmosphere, further comprising a degreasing step of removing organic matter by heating to a temperature in the range of 30 ~ 900 ℃ in an electric furnace
A method for producing a molybdenum-copper sintered alloy.
According to claim 1,
The step (d) is made under a pressure in the range of 10 ~ 3,000 kg / ㎤
A method for producing a molybdenum-copper sintered alloy.
According to claim 1,
The step (e) is made at a temperature in the range of 700 to 1,700 ° C in an electric furnace under a hydrogen atmosphere.
A method for producing a molybdenum-copper sintered alloy.
According to claim 1,
The molybdenum-copper sintered alloy prepared by the above manufacturing method contains 0.1 to 99 wt% of molybdenum and 0.1 to 99 wt% of copper.
A method for producing a molybdenum-copper sintered alloy. delete delete delete

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