JPS5923835A - Production of boride diffused alloy - Google Patents

Abstract

PURPOSE:To produce an electrical contact and sliding material having a surface part dispersed uniformly with borides and having excellent performance, by penetrating and dispersing B in a metallic material having the surface layer part consisting of a thin layer contg. gold, silver, etc. and Be, Mg, Al, etc. CONSTITUTION:>=1 Kinds among Be, Mg, Al, Si, Ti, V, Cr, Mn, Fe, Co, Ni, Ga, As, Zr, Nb, Mo, Pd, Cd, Ta, W and Pt are coated on the surface of gold, silver gold alloy, or silver alloy which is a base material by electroplating or the like; thereafter, the material is heat-treated to diffuse said element into the surface layer part, and metallic material of which the surface layer part from at least the surface down to 0.01-0.1mm. depth contains 0.5-40atom% the above-mentioned elements as an alloy or fine particles and the balance is gold, silver gold alloy, or silver alloy is obtd. B is penetrated and diffused in such metallic material to form the fine particles consisting of the borides of the above-mentioned elements in the surface layer part of the metallic material, whereby the boride diffused alloy is produced and a metallic material suited for an electrical contact material, a sliding material, etc. is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an alloy in which boride is dispersed in the surface layer of a metal material used for electric implants, sliding plates, etc.

Conventionally, powder sintering methods and melting methods have been known to make composite materials of boride and metal. The powder sintering method is a method in which fine boride powder and, for example, copper powder are mixed with appropriate In and sintered at a suitable temperature and in a suitable gas atmosphere to obtain fine boride-dispersed copper. However, this method has the disadvantage that it is difficult to uniformly disperse the boride and the production cost is high.

The melting method is a method in which copper and boride are mixed, melted by high-temperature heating, and solidified by cooling to form a boride-dispersed copper alloy. However, this method has the disadvantage that when the molten alloy is solidified, the boride grains become coarse due to the crystallization of the boride, and there is a limit to the refinement of the boride even by forging. child .

Furthermore, both known methods have the disadvantage that the boride cannot be dispersed only in the surface layer of the metal material, resulting in a decrease in electrical conductivity, for example.

The present invention is completely different from the conventional method described above, in that an alloy such as gold or silver is made with a metal as a constituent element of boride, boron is permeated and diffused from the surface of the alloy, and fine particles of boride are dispersed in the surface layer of the alloy. This method generates a layer of

In addition, the method for manufacturing the boride dispersed alloy of the present invention is such that the surface layer at least from the surface to a depth of 0.01 to 1 mm contains beryllium (Be), magnesium (Mg), aluminum (AI), silicon (Si), and titanium. ('l-1),
Vanadium (V), chromium (Cr), manganese (Mn
), iron ([C), cobalt (Co), nickel (Ni
), gallium (Ga), arsenic (AS), zil: 1 ni
\(Zr), NiAl(Nb), Molybdenum (MO), Palladium (Pd), Cadmium (Cd), Tantalum (T
a) Contains 0.5 to IO atomic % of one or two selected from the group consisting of tungsten (W) and platinum (Pt) as an alloy or fine particles, the balance being gold,
The first step is to adjust the metal, which is silver or gold alloy, or silver alloy, and to avoid permeation and diffusion of boron into the metal,
Forming fine particles made of a boride of one or more elements selected from the above group on the surface layer of Δi'l.
It is characterized by being about 2F.

In the metal material d3 used in the manufacturing method of the present invention, at least the surface layer to a depth of 0.01 to 0.1 mm has 13e, M(1, Δl, 3i, -1'i,
V, Cr, Mn, l2e, Co, Ni, Ga, As, Zr
, Nb, Mo, Pd5Cd, l'a, W, and Pt.
The metal composition of the surface layer was defined as 0 atomic percent, and the balance was gold, silver, gold alloy, and silver alloy.
This is to form boride only in the surface layer. Therefore, for the other parts of the metal material, any metal can be used depending on the purpose of use.

The metal forming the surface layer is [3c, MO, AI, St
XT-i, V, Cr, Mn, Fe, Go, Ni.

Ga, △3.7r, Nb, MOLpd, Cd, T-a,
W and l) (One or more selected from the group consisting of ``2 Be, M (1, △1, etc.) are gold, silver, gold alloy, silver alloy. solid solution or dispersed in
In addition, boron (B) that has diffused and penetrated from the surface of metal material v1
) and can form fine particles of boride 4 in a dispersed manner.

In addition, for other reasons, the borides of the above elements have relatively high hardness, low specific resistance, and high melting points, and for this reason, they are considered to be effective applications for electrical contact materials or materials obtained by the manufacturing method of the present invention. As a sliding material, it has excellent properties. Table 1 lists the physical properties of borides in comparison with those of conventional contacts. According to this, the specific resistance of the boride GEL coating is 20 to 100 x 10.
-6Ωctr, melting point 1270-30/I 0℃,
It has a hardness of 1v1500 to 3000, which is superior to conventional contact materials in terms of melting and hardness.

The reason why the composition ratio of the boride-forming element is set to 0.5 to 40 atomic % is because if it is less than 0.5%, the amount of boride formed is small, so the desired effect peculiar to boride cannot be obtained. This is because when the amount of J increases by 40%, the amount of boride formed increases. This is because the morphology deteriorates, the electrical conductivity and thermal conductivity become low, and the coating layer is likely to crack or peel.

The reason why the surface layer in which the boride is dispersed is set to 0.01 to 0.1 mm is because the boride has the wear resistance, welding resistance, and resistance required for the contact surface area. This is to enable the material to exhibit various effects of oxidation properties, and to meet the requirements of high electrical conductivity, high thermal conductivity, high strength, etc. inside the matrix below the surface layer. That is, avoiding dispersion of boride throughout the interior of the alloy matrix is not necessarily a good idea in order to obtain the high electrical conductivity, high thermal conductivity, and high strength required for the internal matrix H described above.

For this purpose, boride is dispersed only in the surface layer, and the interior below the surface layer is filled with gold, gold, etc. depending on the required properties.
Alternatively, it is preferable to improve the purity of silver or add a reinforcing element.

Note that depending on the composition of the base alloy material in the surface layer, the
Due to the permeation and diffusion of ion, a layer of fine boride particles is not formed, and a non-uniform boride layer may be formed.

In such cases, it is recommended to reduce the composition of boride-forming metallic elements in the base alloy or add other elements that tend to form borides in the base alloy to disperse the boride. preferable.

The entire metal material including the surface layer portion can be an alloy of a predetermined boride-forming element and gold or silver.

In this case, metals having the desired composition are melted to form an alloy.

Conventionally, silver-based contact materials generally include A(]-Nt alloy,
Ao −Cd O1Δ! ]-11O shrine is used. These conventional silver-based contact materials 11 can be used as they are, or even a boride-forming element can be added thereto to form the IU alloy of the present invention. Ni and Cu are silver consumption fil due to arc etc.
1. lno and CdQ have a surface purifying effect.

A typical method for adjusting the metal monthly rate in which only the surface layer is made of a specified alloy is to use gold or silver as the base material, coat the surface with V, N+, etc., and then coat the surface with V, etc. There is also a method in which the metal is heat-treated and diffused into the base material, leaving only the surface layer with a predetermined alloy.

As a method for coating the surface of the base material with V or the like, known methods such as electroplating, chemical plating, vacuum deposition, sputtering, and melting can be employed. Diffusion of V''j into the base material is achieved using the thermal diffusion phenomenon of metal elements at high temperatures.

The shape of the metal material 1 can be any shape depending on the use, such as a plate, a rod, or a line.

The process of penetrating and diffusing boron into the surface of metal metal and dispersing fine particles of polide in the surface layer to form t and -p is as follows:
This can be achieved by the commonly known immersion treatment method. Typical boron treatment methods include the molten salt method, in which the gold material Y1 is immersed in a molten salt bath in which boron is dissolved in vinyl, and the molten salt method, in which the gold material Y1 is immersed in a molten salt bath in which boron has been decomposed. A powder method in which a metal material is embedded in a mixed powder and subjected to heat treatment, and a physical vapor deposition method in which boron is vapor-deposited in a vacuum can be used. The boron that has penetrated into the metal material combines with V, etc. in the base alloy to form boride. The obtained boride is △IB
2, △l B, , AS B1△33e, Qd[3s
, CO213, COD, Crl-3, Cr132,
Fe 13, Fe 2B, VB2, MQ B2, Mg8
4, MO132, MO2B, Nb B, Nb 82,
PtB.

PL 2[33,1-a B, Ta B2. W2B5,
It is one type or a mixture of two or more types of Zr132 and the like.

By these methods, a layer in which boride particles are dispersed in gold, silver, a gold alloy, or a silver alloy is formed. The smaller the size of the boride particles, the better. In the method of the present invention, 0.1
One boride with a particle size of ~10 microns is collected.

The proportion of boride particles in the surface layer is 0.0% by volume.
6 to 50% is desirable. The thickness of the surface layer is 0.01=
0.1mm is good. Note that a thick layer can be achieved by lengthening the initial time for permeation and diffusion of boron or by setting a high degree of thirst in the treatment group 1.

The manufacturing method according to the present invention consists of the above description.

According to the manufacturing method of the present invention, boride can be easily and finely and uniformly dispersed only in the surface layer of the metal.

In addition, the manufacturing cost is lower than that of boride-dispersed alloys produced by conventional sintering methods, and the obtained boride-dispersed alloys have excellent properties.

As shown in the table, boride has higher hardness, higher melting temperature, higher decomposition temperature, and is chemically more stable than conventional contact materials. For this reason, the Is Metal 41 size manufactured by dispersing boride only in the surface layer by the method of the present invention has a surface layer with excellent wear resistance, welding resistance, and arc resistance.
The surface layer part can be used as an electrical contact material and an electrical sliding material with excellent properties as a contact part. In addition, boride has relatively high conductivity, and is finely dispersed only in the surface layer, and the base metal is gold and silver alloys, which have even better conductivity, so it has a high enough conductivity as an electrical contact material. J5 and high thermal conductivity can be obtained. Rinawara,
Since the boride dispersion layer is formed only on the surface layer, the contact system F1
The overall resistance value can be kept low.

According to the manufacturing method of the present invention, the composition inside the matrix of the boride-dispersed alloy can be configured almost arbitrarily, so that the composition inside the matrix can be configured to facilitate bending, punching, coining, etc., and to increase thermal conductivity. You can choose the composition of

The above will be explained using examples.

Example 1 △[195 parts by weight and CO5 parts by weight were dissolved, and △U85.
Diameter 1 (1 q of 1 m of cobalt-gold alloy) [. This is 4mm in diameter using a soothing machine. After forging to a size of 1 mm, it was further rolled into a plate of 1 mm. For this plate material, 4Xb was mixed with borax (Na 213407) 60 weight Φ part, carbonized wood (
84G>Powder (particle size 79-149μm>40ff1
The sample was immersed and held in a 900° C. molten salt bath for 4 hours to diffuse and infiltrate boron into the sample, and then taken out from the bath and cooled in the air.

A part of the obtained sample was cut and the cut surface was examined under a microscope. This micrograph is shown in Fig. 1. In Fig. 1, region 1 represents the boride dispersed layer, and region 2 represents the base material made of cobalt-gold alloy. It can be seen that boride particles with a particle size of 2 to 10 μm are dispersed. In addition, the proportion of boride in the surface layer is about 18% compared to the area of LL, and 1. :.

This boride was confirmed to be CoB as a result of X-ray diffraction and E1') MΔ measurement. Moreover, the metal surrounding the boride was ΔU.

Example 2 90 parts by weight of △u and 10 parts by weight of Ni were dissolved, and △IJ7
313'? A nickel-gold alloy having a Ni content of 27 atomic % was obtained. The same method as in Example 1 was used to avoid boron diffusion and penetration. As a result, a boride-dispersed alloy 111 having a surface layer in which boride particles with a grain size of 5 to 20 μm are dispersed at a depth of about 0.1 qmm from the surface is obtained. This boride is N:zD, and the proportion of this boride in the surface layer is about 32% in terms of area.
Met.

Example 3 Δ(Natsudo V is dissolved, Δu701 quantum%, V30 atomic%
An alloy of This is flexible 6, /lmIn length 24m
A sample was made in the shape of a circle of m +. This trial r1 is 75)%
Boron carbide powder, 5% commercially available ammorum chloride powder, and 20% noflumino powder were embedded in treated powder, and the mixture was placed in an alumina crucible and heated at 900°C.
The mixture was heated for an hour and then air cooled in the crucible.

As a result, a boride dispersed alloy having a monodispersed layer 1 was produced, the cross section of which was shown in FIG.

The thickness of the dispersion layer 1 is approximately 0. Q6 mm, boride particle size (approximately 5-15 μm, boride GJ V [32-'C).

The proportion of boride in the dispersed layer was approximately 36% by area.

Example 4 Δ(197 parts by weight and Cot3ip skewer part were dissolved, Δ9
95 atomic%, C1Ox; %J: Rinaru alloy j! 1k.

Boron was diffused into this alloy in the same manner as in Example 1,
A boride dispersed alloy was produced.

This boride-dispersed alloy had a dispersion layer in which extremely fine boride of C013 having a diameter of about 0.5 μm was dispersed. The thickness of the dispersion layer was 0.09 mmr. The proportion of boride was approximately 6% in terms of area.

Example 5) 97 parts by weight of 〇 and 1-13 parts by weight were melted to obtain an alloy consisting of 93 atomic % of △g and 17 atomic % of iron.

This alloy was diffused and infiltrated with boron in the same manner as in Example 1.

As a result, a boride-dispersed alloy having a dispersion layer 1 was manufactured, a cross-sectional micrograph of which is shown in FIG.

The thickness of the dispersion layer 1 was about 0.25111 m, and the particle size of the boride was about 2 to 15 μm.The proportion of boride in the dispersion layer 1 was about 8% in terms of area. Boride is Ti by X-ray diffraction
It was confirmed that it was Bz.

[Brief explanation of the drawing]

Figure 1 is based on Example 1 in which the base material is alloy 1rζ containing △U85 at% and C015 at%! Table 1 shows the composition of the cross-section in the thickness direction of the manufactured boride-dispersed alloy. Figure 2 shows the composition of the boride-dispersed alloy produced in Example 2 using an alloy of 70% A11, 70% V, and 30% V as the base material. Table 1 shows the composition of the cut surface in the thickness direction of the alloy. Figure 3 shows Ag93 atomic %.
2 is a micrograph showing the composition of a cross-section in the thickness direction of a boride-dispersed alloy manufactured in Example 5 using an alloy containing 7 atomic % Ti as a base material. In the figure, 1 indicates the dispersion layer and 2 indicates the base material region. Patent applicant: Co., Ltd.] Yutaka 0” medium heat? tlI Research Institute Tokai Rika Denki Seisakusho Co., Ltd. Agent Patent Attorney Anama Okawa Patent Attorney Osamu Fujitani

Claims (2)

[Claims] (1) The surface layer at least 0.01 to 0.1 mm below the surface contains beryllium (Be), magnesium (
Mill), aluminum (△1), silicon (Si>
, titanium (Ti), vanadium (V), rim (Cr)
),? Ngan (Mn), iron (Fe), cobalt (CO
), nickel (Ni>, gallium (Ga), arsenic (△S
), zirconium (Zr), di-Δb (Nb), molybdenum (MO), palladium (Pd), cadmium (C
d) contains 0.5 to 40 atomic percent of one or more elements selected from the group consisting of tantalum (Ta), tungsten (W), and platinum (PL) as an alloy or fine particles, with the balance being gold. , a first step of adjusting a metal material that is silver or a gold alloy, or a silver alloy, and boron is permeated and diffused into the metal material (L1), and one or two types selected from the above group are added to the surface layer of the metal material (L1). A method for producing a boride-dispersed alloy, comprising a second step of forming fine particles of borides of one or more elements. (2) By coating the surface of gold, silver, gold alloy, or silver alloy with one or two elements selected from the above group, and then applying heat treatment to diffuse the coated metal into the surface layer. Claim 1 for adjusting the metal material in the first step
Manufacturing method described in section.