JP3090963B2 - Insert material for joining - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joining insert material, which is a brazing filler metal used for joining various metals, and more particularly to a joining material for a copper alloy and steel, steel and steel, etc., and at low cost. The present invention relates to a copper-based joining insert material obtained.

[0002]

2. Description of the Related Art Parts such as a cylinder block and a piston shoe formed by joining a brass-based material or a bronze-based material having excellent slidability to a tough steel material are used in the copper-based sliding member described above. It is an essential requirement that the material and the steel material are firmly joined.

[0003] As the joining method, the following method has conventionally been adopted. Casting joining After setting the preheated steel material in the mold, the molten bronze material is injected and joined. Overlay After the bronze or brass material is placed on the steel base material, or while the bronze or brass powder is supplied onto the base material and melted, at the same time the steel base material is heated and the build-up layers are formed. I do. Brazing Silver or brass brazing between bronze or brass and steel,
A brazing material such as a bronze braze is inserted, and heated and melted in a furnace in a non-oxidizing atmosphere for bonding. Alternatively, in the case of small articles such as shoes, the brazing material is melted and joined by a resistance brazing method in which a current is directly applied while applying pressure.

[0004]

However, the above-mentioned conventional joining methods have the following problems.

[0005] In the cast joining, the productivity of the bronze material is poor due to the low yield of the bronze material, and the cost is high. In addition, brass-based joining containing a large amount of Zn having a high vapor pressure cannot be performed by this cast joining.

[0006] The cladding can be made of either brass or bronze materials, but there is a concern that the productivity is poor, the quality varies widely, and the working environment is deteriorated by high temperature and dust.

In the brazing, when brazing using a brass brazing or bronze brazing in a furnace in a non-oxidizing atmosphere,
Sufficient bonding strength cannot be obtained. In the case of similarly brazing using silver brazing, improvement in bonding strength can be expected,
The cost is very high because the silver wax contains a large amount of silver.

In the resistance brazing method in which a current is applied to the joint while applying pressure to melt the brazing material, if the material to be joined is a bronze material or a brass material, the electrical resistance between these materials and the brazing material is reduced. The difference in the values is small, so that a sufficient amount of heat generation cannot be obtained at the joint. Even if the required calorific value is obtained, it is difficult to melt only the brazing material because the melting point of the material to be joined and the brazing material are close, and it is difficult to control the quality of the joining material.

The present invention has been made to solve the above-mentioned various problems, and an object of the present invention is to provide an insert material as a brazing material which is inexpensive and has a particularly high joining strength to steel. That is.

[0010]

In the conventional brazing method using bronze brazing or brass brazing as a brazing material, the composition of the brazing material is determined so that the brazing material has the lowest melting point. That is, the composition of the brazing filler metal was designed to form a eutectic. When the brazing material is in a eutectic state, it is advantageous in that it has a low melting point. However, on the other hand, the eutectic has the disadvantage of being hard and brittle, which has been one of the causes of the low bonding strength at the time of bonding by brazing.

The present invention is a new brazing material based on the liquid phase sintering technique in the powder metallurgy technique, which is departed from the recognition of the conventional brazing material in which the above-mentioned brazing material is a eutectic fused material. The present invention provides an insert material.

That is, the insert material for joining according to the present invention is a thin plate-shaped compact obtained by compacting and rolling a mixed powder of a metal powder and an alloy powder, and the component composition of the compact is: Sn is 5 to 15 wt% and P is 0.1
~ 2.0wt%, Fe is contained in 0.3 ~ 13wt% ,
The remaining portion is mainly composed of Cu.

Furthermore, a ternary system of Cu—Sn—P and C
With insert material for joining except ternary system of u-Sn-Fe
It is a thin plate compact obtained by compacting and rolling a mixed powder of a metal powder and an alloy powder, and has a component composition of 5 to 15 wt% of Sn and 0.1 to 0.1 wt% of Si. ~ 3.0wt%, Ti is 0.1 ~ 5.0wt%,
P is 0.1 to 2.0 wt%, Fe is 0.3 to 13 wt%
Wherein at least one of them is contained, and the remainder is mainly composed of Cu.

In addition to these two basic components, Ni: 5 wt% or less, Ag: 5 wt% or less, and Pb: 5 wt%
% Or less, and one or more of the components may be added and contained.

The insert material according to the present invention is basically made of bronze (Cu-Sn). The reason is that the bronze-based material has a low melting point and lowers the joining temperature of the copper alloy / steel, is much cheaper than the Cu-Ag system, and has a low alloy vapor pressure unlike brass containing Zn. , Etc.

The above effect is effective when the Sn content is 5 wt% or more, but when the Sn content exceeds 10 wt%, a β-type intermetallic compound of Cu—Sn precipitates at the joint interface. At first, if the content is more than 12 wt%, the precipitation amount of the β-type intermetallic compound becomes large, and the joint made of the insert material becomes brittle. Therefore, the content of Sn is set to 5 to 15% by weight, preferably 5 to 10% by weight. In particular, when the bonding area is large, it is preferable that the Sn content does not exceed 10 wt%.

P is added in order to improve the bonding property at the bonding interface. That is, P has the function of increasing the fluidity of the liquid phase generated at the time of bonding and reducing and dispersing the oxide film generated at the bonding interface by its strong reducing ability. In order to exhibit these functions, the content of P is preferably 0.1 to 2.0 wt%, and more preferably 0.6 to 1.0 wt%. If there is too much P, C
u ₃ P is crystallized in a eutectic state, and since Cu ₃ P is brittle, it has an adverse effect in improving the bonding strength.

However, in the ternary system of Cu-Sn-P, 8
When heated to 00 ° C to 850 ° C or higher, O ₂ is dissociated and foams easily. In the present invention, in order to prevent such foaming, F
e is added. This foaming preventing effect is due to the deoxidizing action of Fe. Further, the addition of Fe is carried out by the eutectic C
It is also effective in preventing crystallization of u ₃ P.

Fe is preferably added as iron powder having a particle size of 250 mesh or less or Fe—P alloy powder having a particle size of 250 mesh or less (P content of 15 wt% or more). When added in the form of a P alloy powder, Fe containing mainly iron having a particle size of 50 μm or less is used.
It is effective to adjust the amount of Fe in the whole by adding an appropriate amount of powder. The content of Fe is preferably in the range of 0.3 to 13% by weight, and if too high, the melting point of the insert material becomes high, which is not preferable.

The purpose of the above-mentioned reduction and deoxidation functions of P and Fe can be similarly achieved by adding Si or Ti alone or in combination. The content is Si: 0.3-3.0wt%, T
i: It is preferably in the range of 0.1 to 5.0% by weight, and if too much, too much intermetallic compound is precipitated and becomes brittle, which is not preferable.

In addition to the basic composition obtained by adding P and Fe to the above-mentioned Cu-Sn system or the basic composition obtained by adding Si and Ti singly or in combination, the present invention provides an N content of 5 wt% or less.
i. It is possible to add one or more of Ag of 5 wt% or less and Pb of 5 wt% or less.

Of these additives, Ni, Si and Ti
Is added for the purpose of strengthening the insert material itself and the bonding interface itself. Ni and Si significantly increase the shear strength due to the coexistence of appropriate amounts, respectively. However, if the total amount of Ni and Si exceeds 4 wt%, the intermetallic compound starts to precipitate and becomes brittle, and the bonding strength becomes weak. It is preferable to keep this amount at 4 wt% or less.

The same can be said for Ti and Si as for Ni and Si. When adding Ti alone, it is preferable to add Cu-Ti alloy powder, but when adding in the form of titanium hydride powder, titanium hydride is more preferable because it has excellent sinterability. I can say.

Ag and Pb are added for the purpose of improving the wettability between the liquid phase and steel. The effect of this wettability improvement is as follows:
This is particularly effective when each of g and Pb contains 1 to 2% by weight. The larger the amount of Ag and Pb, the more liquid phase is formed at the time of bonding and the better the wettability.
In some cases, strength deterioration due to the coexistence of Pb and Pb may start to adversely affect the bonding strength. Moreover, since Ag is expensive, it is desirable to keep it as small as possible.

Since the shear strength often deteriorates significantly when Si and Pb coexist, it is preferable to avoid a combination of additions in which Si and Pb coexist.

The composition of the components as described above, that is, basic Cu, Sn, Fe, Cu-Sn, Cu-P, Fe-
After mixing metal powder and alloy powder such as P, or further appropriately mixing additional components, and mixing, pressing and rolling, or using pressing and rolling together, for example, into a thin plate having a thickness of 1 mm or less It is molded to produce a joining insert material.

[0027]

When joining a copper alloy and steel or steel and steel using the insert material according to the present invention, the joint is heated in a non-oxidizing atmosphere with the insert material interposed therebetween. By this heating, a part of the powder component of the insert material is melted to form a liquid phase. At the same time, the heating temperature is adjusted so that the solid phase remains at least 50 vol% or more. This prevents a large amount of brittle Cu-Sn intermetallic compound from being precipitated at the bonding interface.

On the other hand, the molten component diffuses in the solid phase on the powder surface, and at that time, reacts with the solid phase component to generate a tough structure different from eutectic. At the same time, the molten components diffuse while wetting the joining surfaces of the members to be joined, and the cooperative action of these components maintains the adhesion and joining properties between the insert material and the members to be joined.

Finally, the melted components are cooled and solidified to complete the sintering. In this manner, in the insert material according to the present invention, by performing the joining based on the liquid phase sintering, the intended joining with high joining strength is achieved.

When the insert material according to the present invention is applied to the resistance brazing method, since the insert material is in a powdered state, a large electric resistance is generated, an effect of concentrating heat generation due to electric current is exerted, and furthermore, the powder material is used. The effect of concentrating heat generation is enhanced by the fact that a portion is easily melted.

Therefore, only the insert material can be selectively melted at the time of joining copper alloys such as bronze and brass, and can be suitably used for joining small parts by resistance brazing.

[0032]

As described above, by performing joining using the insert material according to the present invention, the formation of a eutectic crystal or an intermetallic compound is avoided or suppressed, and as a result, the joining strength is greatly improved. It was possible to obtain a shear strength of about 15 kg / mm ² or more.

By using the insert material according to the present invention, it becomes possible to provide various hydraulic equipment parts manufactured by joining a sliding material made of bronze or brass to steel and various industrial parts at low cost and with good quality. Was. In addition, the insert material of the present invention does not need to contain a large amount of expensive Ag, so that it is more advantageous in terms of cost.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described with reference to the drawings.

First, electrolytic copper powder (CE1 manufactured by Fukuda Metal Co., Ltd.)
5), Cu-33Sn (atomized powder, manufactured by Fukuda Metal Co., Ltd.
50), carbonyl Fe powder (manufactured by SCM, average particle size 5μ)
m), Cu8P (manufactured by Fukuda Metals Co., Ltd.-250 or less), carbonyl Ni powder (manufactured by Inconel Co., average particle size 5 μm), metal Si powder (-♯250), Fe-27P (Fukuda Metals Co., Ltd.-# 35)
0 or less), Cu30Ti (Molitec Corporation-$ 250 or less)
Were used as raw materials, and were blended so as to have the compositions shown in Nos. 1 to 15 in Table 1. Next, after mixing for 1 hour with a V-type mixer, the surface pressure was 2.5 ton / cm to 25 mm in diameter and 0.2 mm in thickness.
Press-molded in ² . Further, it was rolled to a thickness of 0.1 mm by a rolling mill to prepare an insert material of the present invention.

Each of these insert materials has a diameter
20mm, height 10mm steel (SCM440H) and diameter 20mm,
The sheet was sandwiched between a high-strength brass material having a thickness of 3 mm (P31C made by Chuetsu Alloy) and joined by heating at 900 ° C. for 1 hour in an ammonia decomposition gas (AX gas) atmosphere.

From these materials, as shown in FIG.
A shear force measurement test piece in which the brass material 3 is joined to the upper surface of the steel material 1 via the joining portion 3 having a predetermined area is cut out, and the joining portion 3
Table 1 also shows the results of shear fracture. From Table 1, when joined with the insert material according to the present invention, the basic ingredients 13 kg / mm ² or more shear failure stress with a composition obtained, 20 kg / mm ² by adding further additives appropriately It can be seen that the above large shear fracture stress can be obtained.

[Table 1]

[Brief description of the drawings]

FIG. 1 is a perspective view of a test piece for measuring a shear fracture stress of a portion joined using the joining insert material of the present invention.

[Explanation of symbols]

 1 Steel 2 Brass 3 Joint

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ identification code FI B23K 103: 04 (58) Fields investigated (Int.Cl. ⁷ , DB name) B23K 35/30 310 B23K 1/19 B23K 35 / 40 340

Claims (3)

(57) [Claims] 1. A thin plate-shaped compact obtained by compacting and rolling a mixed powder of a metal powder and an alloy powder,
The component composition of this compact is such that Sn is 5 to 15 wt%, P is 0.1 to 2.0 wt%, Fe is 0.3 to 13 wt%, and the balance is mainly composed of Cu. Characteristic insert material for joining. 2. Cu-Sn-P ternary system and Cu-S
It is a joining insert material excluding the ternary system of n-Fe.
The compact is a thin plate compact obtained by compacting and rolling a mixed powder of a metal powder and an alloy powder, and has a component composition of 5 to 15 wt% of Sn and 0.
1 to 3.0 wt%, 0.1 to 5.0 wt% of Ti, 0.1 to 2.0 wt% of P, and at least one of 0.3 to 13 wt% of Fe , with the balance being mainly the rest. Cu
An insert material for joining, characterized in that the insert material comprises: 3. The method according to claim 1, wherein the remainder mainly composed of Cu is
Ni: 5 wt% or less, Ag: 5 wt% or less, and Pb:
The bonding insert material according to claim 1 or 2, comprising one or more components selected from the group consisting of 5 wt% or less.