JP2002309326A - Attrition-resistant copper alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a copper alloy having excellent resistance integrating discharge attrition resistance and mechanical attrition resistance required for the contact material of switches. SOLUTION: The attrition resistant copper alloy consists of an alloy to which electric conductivity of >=70% IACS has been imparted by performing heat treatment to copper containing one or more kinds of components selected from, by weight, 0.1 to 2.4% Fe, 0.1 to 0.5% Co and 0.1 to 0.5% Ni, and containing 0.05 to 0.2% P so as to control the weight of the above one or more kinds of components to the one 3 to 12 times the weight of P.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wear-resistant copper alloy, and more particularly to a copper alloy excellent in discharge wear resistance and mechanical wear resistance required as contact materials for switches and the like.

[0002]

2. Description of the Related Art In a switch section of various electric devices,
An arc discharge occurs at the time of ON / OFF switching, and the contact material constituting the switch unit is worn. In particular, at the time of transition from ON to OFF, the current density increases due to the decrease in the contact area due to the separation between the contacts, and the component material is melted by the Joule heat generated thereby, so that a bridge is formed between the contacts. Become.

[0003] The formed bridge is cut by the separation between the contacts, and the contact material at the cut portion is evaporated and ionized and moves between the contacts, causing arc discharge. When the arc discharge occurs, the material moves from one side to the other side, and the components of the contact on one side are worn.
The wear of the components acts to hinder stable contact between the contacts, causing contact failure.

[0004] In general, tough switches are used for electric switches such as tough pitch copper, oxygen-free copper, and copper alloys containing a small amount of silver. Although these copper-based materials have a problem that an oxide film is easily formed on the surface, they are more inexpensive and have good electrical and thermal conductivity. It is widely used as a contact material for home appliances or a contact material for automobiles.

[0005] Good electric conductivity and thermal conductivity (hereinafter simply referred to as electric conductivity) suppress the Joule heat generated at the time of ON / OFF switching or lead to the effect of conducting and releasing the generated heat to the outside. It works to effectively reduce discharge wear caused by discharge. Therefore,
Copper or a copper alloy characterized by having good conductivity can be said to be a suitable material as a contact material for switches.

[0006]

However, according to the conventionally known copper material for a contact, although it is excellent in discharge wear resistance, it does not have sufficient strength in terms of strength. Have a problem. That is, a repetitive load acts on the contacts of the switches due to the contact and separation while rubbing at the time of ON / OFF switching. Therefore, resistance to mechanical wear due to this is required, A copper material that satisfies this property while satisfying the discharge wear property has not yet emerged.

In order to increase the resistance to mechanical wear, it is effective to increase the strength by adding an alloying element. Because it usually leads to hindrance,
It has been considered difficult to achieve both discharge wear resistance and mechanical wear resistance.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a copper alloy excellent in overall wear resistance, which has both discharge wear resistance and mechanical wear resistance required as contact materials for switches and the like.

[0009]

According to the present invention, in order to achieve the above object, 0.1 to 2.4% by weight of Fe, 0.1 to 2.4% by weight.
0.5% by weight Co and 0.1-0.5% by weight N
copper containing unavoidable impurities containing one or more components selected from i and 0.05 to 0.2% by weight of P such that the one or more components are 3 to 12 times the amount of P An object of the present invention is to provide a wear-resistant copper alloy comprising an alloy having a conductivity of 70% or more by performing a heat treatment.

The features of the copper alloy according to the present invention are Fe, Co
And heat treatment of an additive component selected from the group consisting of Ni and Ni, or a combination thereof, to form a compound Fe2P, Co2P, Ni5P2 or Ni
The purpose is to form 2P and form precipitates of this compound in copper.

As a result of precipitation of the compound with P in the copper, it is possible to improve the hardness by dispersion strengthening, and to reduce the amount of alloy components existing in a solid solution state in the copper of the matrix. Therefore, the above-mentioned components are important factors in achieving both the discharge wear resistance due to the strength improvement and the mechanical wear resistance due to the conductivity improvement.

In order to optimize the above-mentioned effects, it is necessary to define the amount of each component added in the following range as described above. That is, it is necessary to set Fe to 0.1 to 2.4% by weight and Co and Ni to 0.1 to 0.5% by weight, respectively.
Must be set so that the former is 3 to 12 times P.

If the amount of the component selected from the group consisting of Fe, Co and Ni is below the above range, a sufficient improvement in strength cannot be obtained. The effect of improving conductivity is not exhibited, and surface oxidation is apt to occur. Further, if the above-mentioned ratio set between these components and P deviates, the deviated components will be present in a solid solution state in the copper of the mother phase. Discharge abrasion is impaired.

In the present invention, each component added together with P has a relative difference in the effect of improving strength and conductivity. Fe and Co have characteristics of imparting low strength and high conductivity, while Ni has characteristics of imparting high strength and low conductivity and tend to decrease the conductivity when the ratio increases. There is. Therefore, in order to achieve higher strength and conductivity, it is desirable to combine these characteristics in a well-balanced manner. In this sense, when each component is set as follows, the best results can be obtained. Become.

That is, one or both of Fe and Co are selected and their amounts are each 0.1 to 0.5% by weight.
And the amount of Ni and the amount of P
0.5% by weight and 0.05 to 0.2% by weight, and the total amount of Fe and / or Co and Ni is set to 3 to 10 times P, and Ni and Fe and / or ) The weight ratio with Co is set to 0.8 for the former and 1 for the former.
With the above settings, the strength and conductivity are the best, and excellent mechanical wear resistance and excellent discharge wear resistance are guaranteed.

The conductivity given to the copper alloy of the present invention is as follows:
It must be at a level of 70% IACS or higher. In order to suppress the consumption of the material due to arc discharge and to secure excellent discharge wear resistance, it is preferable to have good conductivity such as pure copper, but on the other hand, mechanical strength by increasing the strength It is not possible to reduce the loss while maintaining the conductivity of pure copper.

Therefore, it is necessary to set an appropriate conductivity in order to make these contradictory characteristics compatible.
% IACS or more is a preferable electric conductivity for that.
When this conductivity is ensured, the resistance to arc discharge wear based on good conductivity and the resistance to mechanical wear based on high strength are compatible. This conductivity can be realized by subjecting the copper alloy to a heat treatment at an appropriate temperature.
~ 600 ° C is a preferred range. It is difficult to secure a conductivity of 70% IACS or more regardless of the lower limit or upper limit of this range.

In the copper alloy of the present invention, a form in which a specified component other than the above-mentioned components is added is also possible. M
g, Al, Ti, Cr, Mn, Zn, Zr, Mo, A
g, In or Sn is suitable as the specific component, and one or more of these are added in an appropriate amount. These components act to improve the hardness, and the effect is best when the added amount is 0.001 to 0.3% by weight.

If the added amount is less than 0.001% by weight, the effect is insufficient. On the other hand, if it exceeds 0.3% by weight, the conductivity is reduced in these and the discharge wear resistance is adversely affected. Some things are not desirable. When two or more of these are used in combination, it is preferable to set the total amount to 1% by weight or less from the viewpoint of ensuring discharge resistance.

[0020]

Next, embodiments of the wear-resistant copper alloy according to the present invention will be described with reference to Tables 1 and 2.

Examples 1 to 9 Copper alloys based on oxygen-free copper having the compositions shown in Table 1 were melted in a high-frequency melting furnace and cast into ingots having a diameter of 30 mm and a length of 250 mm. Next, these ingots were extruded hot, formed into a plate having a width of 30 mm and a thickness of 8 mm, and then subjected to cold rolling so as to have a thickness of 2.0 mm, and then at 500 ° C. for 2 hours. Heat treatment,
Subsequently, the copper plates of Examples 1 to 9 were manufactured by performing cold rolling so that the thickness became 1.0 mm.

[0021]

Comparative Examples 1 to 7 In the production of the copper plates shown in Examples 1 to 9, the copper alloys of Comparative Examples based on oxygen-free copper shown in Table 1 were used, and the other components were set under the same conditions. The copper plates of Comparative Examples 1 to 7 were manufactured.

[0022]

2. Description of the Related Art In the production of copper sheets shown in Examples 1 to 9,
A conventional copper plate shown in Table 1 was manufactured by using tough pitch copper as a material and setting other conditions to the same conditions.

[0023]

Examples 10 to 12 In the production of the copper sheets shown in Examples 1 to 9, the oxygen-free copper-based copper alloy shown in Example 1 in Table 1 was used, and the heat treatment conditions were changed to those in Table 2. The copper plates of Examples 10 to 12 were manufactured by setting the conditions shown and further setting the other conditions the same.

[0024]

Comparative Examples 8 and 9 In the production of the copper plates shown in Examples 1 to 9, the oxygen-free copper-based copper alloy shown in Example 1 of Table 1 was used, and the heat treatment was performed under the conditions shown in Table 2. , And the other conditions were set to the same conditions, thereby producing the copper plates of Comparative Examples 8 and 9.

[0025]

[Table 1]

[0026]

[Table 2]

The characteristics shown in Tables 1 and 2 are the results of tests performed on the above Examples, Comparative Examples and Conventional Examples. In addition, the test method of a consumption depth is as follows. 3mm x 3mm cathode contact and 10m from manufactured copper plate
An anode contact of mx 20 mm was sampled, and 4
An open voltage of 8 V is applied, and 1.
The conditions were set so that a current of 0 A flows, and the depth of the concave portion formed on the anode contact when contact and separation between the contacts were repeated 100,000 cycles at 1 cycle / second was measured.

According to Table 1, the example according to the present invention shows a conductivity of 70% IACS or more, which gives good discharge wear resistance, and also shows a high level of hardness (ie, strength). In comparison, in the case of the conventional example, an average of 60
The point is a low hardness, and thus the wear depths indicated by both clearly show the difference in mechanical wear resistance.

In Comparative Examples 1 and 2 in which the amounts of Ni and P, Co, Ni and P are out of the range of the present invention, and in Comparative Examples 3 and 4 in which the ratio of the total amount of Fe and Ni to P is out of the range of the present invention. Has a conductivity of less than 70% IACS and therefore
Due to the low discharge wear resistance due to this, a significant wear depth is shown. Table 1 shows Fe, N in the present invention.
The effects of addition of i and P, the reason for limiting the amount of addition of these components, and the reason for limiting the combination ratio with P are clearly shown.

The high hardness of Examples 7 to 9 is due to the effect of the addition of specific components such as Mg and Zn. Therefore, when implementing the present invention, it is not possible to add these components. preferable. However, as shown in Comparative Examples 5 to 7, there is an effect on the electrical conductivity due to the excessive addition. Therefore, when adding these components, consideration should be given to the amounts.

On the other hand, according to Table 2 which shows the effects of the heat treatment conditions, those according to Examples 10 to 12 in which the heat treatment temperature is set in the range of 400 to 600 ° C. show high levels of conductivity and hardness, and On the other hand, in Comparative Examples 8 and 9 in which the heat treatment temperature was out of the above range, the conductivity did not reach 70% IACS, and the discharge resistance was low. It shows a large wear depth due to lack of wearability. For this reason, in implementing the present invention, consideration should be given to the heat treatment conditions.

[0032]

As described above, according to the present invention,
One or more components selected from 0.1 to 2.4% by weight of Fe, 0.1 to 0.5% by weight of Co, and 0.1 to 0.5% by weight of Ni; A 70% IAC is obtained by heat-treating a copper alloy containing 0.2% by weight of P so that the above-mentioned one or more components are in an amount of 3 to 12 times P.
The present invention provides a copper alloy having a conductivity of at least S and thereby having a resistance to discharge wear and a resistance to mechanical wear at the same time, and its usefulness is great. In addition, this copper alloy is sufficiently provided with the original low cost of the copper material, and it is possible to surely obtain the economic benefits.

Claims (5)

[Claims] (1) 0.1 to 2.4% by weight of Fe, 0.1 to
0.5% by weight Co and 0.1-0.5% by weight N
copper containing unavoidable impurities containing one or more components selected from i and 0.05 to 0.2% by weight of P such that the one or more components are 3 to 12 times the amount of P A wear-resistant copper alloy comprising an alloy having a conductivity of 70% IACS or more by heat treatment. 2. The wear-resistant copper alloy according to claim 1, wherein said alloy is given the electrical conductivity by being subjected to said heat treatment at 400 to 600 ° C. 3. The alloy according to claim 1, wherein the alloy contains 0.1 to 0.5% by weight of Fe.
And 0.1 to 0.5% by weight of one or both components of Co, 0.1 to 0.5% by weight of Ni, and 0.05
０．２0.2% by weight of P so that the sum of the one or both components and Ni is 3 to 10 times the amount of P, and the weight ratio of Ni to the one or both components is 1 2. The wear-resistant copper alloy according to claim 1, wherein the latter is included so that the latter is 0.8 or more. 4. The alloy according to claim 1, wherein the alloy is Mg, Al, Ti, Cr, M
The wear-resistant copper alloy according to claim 1, further comprising one or more additional components selected from n, Zn, Zr, Mo, Ag, In, and Sn. 5. The composition according to claim 1, wherein
The wear resistance according to claim 4, characterized in that it is added within a range of 0.3% by weight, and when two or more of them are added, the total is 1% by weight or less. Copper alloy.