KR20180086781A - Electrical contact material - Google Patents

Abstract

An electrical contact material according to an embodiment of the present invention includes a positive (+) contact including a silver-oxide composite material containing 13 to 17 wt% of oxide and the remainder of Ag, and a negative (-) contact facing the positive (+) contact and comprising a silver-oxide composite material comprising Au, Ag, AgNi, AgCu or 13 to 17 wt% of oxide and the remainder of Ag. The durability of the electrical contact material can be improved.

Description

Electrical contact material {ELECTRICAL CONTACT MATERIAL}

Electrical contact material. Specifically, the present invention relates to an electrical contact material improved in durability by different materials of a positive (+) contact and a negative (-) contact.

Countermeasures Switches A so-called relay consists of a pair of fixed contacts and a movable contact. The electromagnet receiving the input of the switch operates to move the movable contact so that it contacts with the fixed contact to open or close the circuit or to switch the circuit.

When driving a part that uses a certain load or more, the relay contact is repeatedly attached and detached, so that arc and heat are generated between the electrical contacts.

When using a common DC current, the metal atoms transition as a constituent of the contact every time the contact touches, and a protrusion is formed in one contact (- contact) and a recessed shape is formed in the opposite contact (+ point). If such protrusions continue to be formed, the shape of the contact point becomes poor, and abnormal contact phenomenon due to fusion between the contacts or locking between the protrusions and the grooves may occur, which may cause the problem of continuous operation of the parts or inoperability problems .

Even if the protrusion growth does not occur, if the components of both contacts are not suitable, fusion between contacts due to arc heat or energized heat may occur during relay operation. This phenomenon is occurring more frequently as the size of the countermeasures switch is reduced and the distance between the contact points is decreased.

Provided is an electrical contact material improved in relay energization performance by suppressing an increase in surface contact resistance. Specifically, the material of the positive (+) and negative (-) contacts is different to provide an electrical contact material having improved durability.

The material of the electrical contact according to the embodiment of the present invention is disposed opposite to the positive (+) contact and the positive (+) contact including a silver-oxide composite material containing 13 to 17% by weight of oxide and the remainder Ag, (-) contact comprising a silver-oxide composite material comprising Ag, AgNi, AgCu, or 3 to 12 wt% of an oxide and the remainder Ag.

The silver-oxide composite material may include oxides such as tin oxide, tin-indium oxide, zinc oxide, or bismuth oxide.

The silver-oxide composite material may include oxide particles distributed in a silver matrix and a silver matrix. The average particle size of the oxide particles may be 0.1 to 0.7 占 퐉.

The positive (+) contact may be located on the surface of the positive (+) contact and may comprise an oxide layer containing 20 to 60 wt% oxide. The thickness of the oxide layer may be 1 to 30 占 퐉.

The negative (-) contact includes AgNi and may contain Ni in excess of 0 wt% and 30 wt% or less.

The negative (-) contact includes AgCu, and can include Cu in excess of 0 wt% and 60 wt% or less.

The negative (-) contact comprises a silver-oxide composite, and the silver-oxide composite of the negative electrode contact may comprise 5 to 10% by weight of oxide and the remainder of Ag.

According to an embodiment of the present invention, durability can be improved by using different materials for the positive electrode contact and the negative electrode contact.

1 is a schematic view illustrating an electrical contact material according to an embodiment of the present invention.
FIG. 2 is a schematic diagram schematically illustrating a state in which a metal atom that is cationized by arc generation moves to a negative electrode contact point in an electrical contact material.
3 is a schematic diagram schematically illustrating the process of forming the oxide layer at the anode contact.
4 is a photograph of a section of a positive electrode contact after 200,000 times of operation of the electrical contact material of Example 1. Fig.
5 is a photograph of a cross section of a negative electrode contact after 200,000 times of operation of the electrical contact material of Example 1. Fig.
6 is a photograph of a cross section of a positive electrode contact after 200,000 times of operation of the electrical contact material of Comparative Example 3. Fig.
7 is a photograph of a cross section of a negative electrode contact after 200,000 times of operation of the electrical contact material of Comparative Example 3. Fig.
8 is a scanning electron microscope (SEM) image of a cross-section of a positive electrode contact of the electrical contact material of Example 1. Fig.
9 is a scanning electron microscope photograph of a cross section of a positive electrode contact among the electrical contact materials of Example 4. Fig.
10 is a scanning electron microscope (SEM) image of a cross-section of a positive electrode contact of the electrical contact material of Comparative Example 1. Fig.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. However, it is to be understood that the present invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It is intended that the disclosure of the present invention be limited only by the terms of the appended claims. Like reference numerals refer to like elements throughout the specification.

When referring to a portion as being "on" or "on" another portion, it may be directly on or over another portion, or may involve another portion therebetween. In contrast, when referring to a part being "directly above" another part, no other part is interposed therebetween.

Thus, in some embodiments, well-known techniques are not specifically described to avoid an undesirable interpretation of the present invention. Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Whenever a component is referred to as "including" an element throughout the specification, it is to be understood that the element may include other elements, not the exclusion of any other element, unless the context clearly dictates otherwise. Also, singular forms include plural forms unless the context clearly dictates otherwise.

1 schematically shows an electrical contact material according to an embodiment of the present invention.

Referring to FIG. 1, an electrical contact material 100 according to an embodiment of the present invention includes a positive electrode contact 10 and a negative electrode contact 20 disposed opposite to the positive electrode contact 10. The electrical contact material 100 of FIG. 1 is only for illustrating the present invention, and the present invention is not limited thereto.

Hereinafter, each of the components of the electrical contact material 100 will be described in detail.

As shown in Fig. 2, at the DC load, the projection formation by the contact transition has a directionality. The main component of such a phenomenon is that when a metal atom collides with an electron due to the generation of an arc, the cationized metal atom is attracted to the negative electrode (-) contact point 20, Because it moves toward the contact 20 side.

Due to the directionality of the contact material transfer, it is necessary to change physical properties of the material of the positive electrode contact 10 and the negative electrode contact 20. Specifically, in the case of the positive electrode contact 10, the arc resistance (the consumed amount is small) and the resistance to fusing are the most important factors, and in the case of the negative electrode contact 20, resistance to fusing and low contact resistance are preferentially required.

As described above, the positive electrode contact 10 is required to have the highest resistance to arc (low consumption) and resistance to fusing. For this purpose, the anode contact 10 comprises a silver-oxide composite. Specifically, the silver-oxide composite material contains 13 to 17% by weight of an oxide and the balance of (Ag).

As described above with reference to FIG. 2, when the metal (Ag) atoms collide with the electrons by the generation of the arc, the cationized metal (Ag) atoms 11 move toward the cathode contact 20. However, when the anode contact 10 includes a silver-oxide composite material as in the embodiment of the present invention, the oxide 12 in the composite material moves relatively less than the metal (Ag) atoms 11, The cationized metal (Ag) atoms preferentially move to the cathode contact 20 side. As a result, a large amount of the oxide 12 remains on the surface portion of the anode contact 10 to form the oxide layer 13, and this oxide layer 13 hinders further transition of the metal (Ag) atoms. 3 is a schematic diagram schematically illustrating the process of forming the oxide layer 13 in the anode contact 10.

If the amount of the oxide contained in the silver-oxide composite material is too small, the ability to suppress the transition due to the arc is deteriorated. If the amount is too large, the oxide layer is excessively formed and the contact resistance of the anode contact 10 is greatly increased. Accordingly, oxides may be included in the silver-oxide composite material within the above-mentioned range.

At this time, the oxide may include tin oxide (SnO ₂ ), tin-indium oxide (SnInO _x ), zinc oxide (ZnO), or bismuth oxide (BiO _x ).

The silver-oxide composite material may include oxide particles distributed in a silver matrix and a silver matrix. The average particle diameter of the oxide particles may be 0.1 to 0.7 占 퐉. If the average particle diameter of the oxide particles is too small, the ability to suppress the transition due to the arc may be deteriorated. If the average particle size of the oxide particles is too large, the contact resistance of the anode contact 10 can be greatly increased. Therefore, the average particle diameter of the oxide particles can be controlled within the above-mentioned range.

3, the positive (+) contact 10 is located on the surface of the positive (+) contact 10 and comprises an oxide layer 13 comprising 20 to 60 wt% oxide. The thickness of the oxide layer may be 1 to 30 占 퐉.

As described above, the negative electrode contact 20 is preferentially required to have resistance to fusing and low contact resistance. For this purpose, the cathode contact 20 may comprise Au, Ag, AgNi, AgCu or a silver-oxide composite. Specifically, when the cathode contact 20 includes AgNi, Ni may be contained in an amount of more than 0 wt% and not more than 30 wt%. The remainder is Ag. If the content of Ni is too large, the strength and conductivity of the contact may be greatly reduced. When the cathode contact 20 comprises AgCu, it may contain more than 0 wt% and not more than 60 wt% of Cu. If the content of Cu is too large, the oxidation of the contact may easily occur. When the cathode contact 20 includes a silver-oxide composite material, it may include a silver-oxide composite material having a smaller oxide content than the anode contact 10. Specifically, it may contain 3 to 12% by weight of oxide and the balance of Ag. When the content of the oxide is too large, the contact resistance is excessive and the conductivity and durability of the contact can be greatly reduced. More specifically, the silver-oxide composite material of the cathode contact 20 may contain 5 to 10% by weight of the oxide and the balance of Ag.

As described above, the electrical contact material 100 according to an embodiment of the present invention can improve the durability by attaching different materials to each contact point.

The positive electrode contact 10 and the negative electrode contact 20 described above may further include a base layer 30 as well as a surface layer including the above-described material. The base layer may comprise Cu or a Cu alloy. The base layer may comprise two or three cladding layers.

Hereinafter, preferred embodiments and comparative examples of the present invention will be described. However, the following examples are only a preferred embodiment of the present invention, and the present invention is not limited to the following examples.

Experimental Example

As summarized in Table 1 below, the material of the electrical contact was manufactured by applying the material of the positive electrode contact and the negative electrode contact. The point at which the resistance value becomes unstable by operating the manufactured electrical contact material with the motor rated voltage (12 V) and the current (10 A) was recognized as the operation frequency.

The number of times of each operation was measured and summarized in Table 1 below.

Positive (+) contact Cathode (-) contact Number of operations Example 1 AgSnInO _x
(Oxide 14% by weight) AgCu
(Cu 20% by weight) 738,000 Example 2 AgSnInO _x
(Oxide 14% by weight) AgSnInO _x
(9 weight% of oxide) 421,800 Example 3 AgSnInO _x
(Oxide 14% by weight) AgNi
(Ni 10% by weight) 372,500 Example 4 AgZnO
(Oxide 14% by weight) AgCu
(Cu 20% by weight) 597,200 Example 5 AgZnO
(Oxide 14% by weight) AgNi
(Ni 10% by weight) 342,600 Comparative Example 1 AgCu
(Cu 20% by weight) AgCu
(Cu 20% by weight) 41,700 Comparative Example 2 AgCu
(Cu 20% by weight) AgSnInO _x
(Oxide 14% by weight) 62,180 Comparative Example 3 AgSnInO _x
(9 weight% of oxide) AgSnInO _x
(9 weight% of oxide) 180,300 Comparative Example 4 AgSnInO _x
(Oxide 14% by weight) AgSnInO _x
(Oxide 14% by weight) 221,200 Comparative Example 5 AgZnO
(Oxide 14% by weight) AgZnO
(Oxide 14% by weight) 198,700 Comparative Example 6 AgZnO
(Oxide 14% by weight) AgSnInO _x
(Oxide 14% by weight) 123,200 Comparative Example 7 AgSnInO _x
(9 weight% of oxide) AgCu
(Cu 20% by weight) 289,300

As shown in Table 1, when the silver-oxide composite material is used as the anode contact material, it is confirmed that the durability is superior to the Comparative Examples 1 and 2 using the silver alloy.

In addition, even in the case where the silver-oxide composite material is used as the anode contact material, the durability of Comparative Example 3 and Comparative Example 7 in which the oxide content is not appropriate is poor compared with the Examples. Also, in Comparative Examples 4 to 6 using a silver-oxide composite material having the same amount of oxides, the durability of the negative electrode contact material was also inferior to that of the Example even when a silver-oxide composite material was used as the positive electrode contact material have.

Figs. 4 and 5 are photographs of cross-sections of the positive electrode contact and the negative electrode contact after the electric contact material of Example 1 is operated 200,000 times. As shown in FIG. 4 and FIG. 5, it can be seen that erosion did not occur excessively at specific portions of both the positive electrode contact and the negative electrode contact, and the relatively uniform thickness was maintained.

FIGS. 6 and 7 are photographs of cross sections of the positive electrode contact and the negative electrode contact after 200,000 times of operation of the electrical contact material of Comparative Example 3. FIG. As shown in FIGS. 6 and 7, it can be seen that the base layer is exposed due to excessive erosion at specific sites of both the positive electrode contact and the negative electrode contact.

Figs. 8 and 9 are scanning electron micrographs of cross-sections of positive electrode contacts among the electrical contact materials of Examples 1 and 4. Fig. As shown in Figs. 8 and 9, it can be confirmed that an oxide layer is formed on the surface portion of the anode contact (a rectangle indicated by a dotted line). It can be confirmed that this oxidation layer inhibited the transition of Ag.

10 is a scanning electron microscope (SEM) image of a cross-section of a positive electrode contact of the electrical contact material of Comparative Example 1. Fig. It can be confirmed that an oxide layer is not formed at all, unlike the embodiment.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. As will be understood by those skilled in the art. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

100: Electrical contact material 10: Bi-polar contact
11: Ag atom 12: oxide
13: Oxidation layer 20: Negative electrode contact
30: base layer

Claims (9)

A positive (+) contact comprising a silver-oxide composite material comprising 13 to 17% by weight of oxide and the remainder Ag, and
(-) contact comprising a silver-oxide composite material disposed opposite the positive (+) contact and comprising Au, Ag, AgNi, AgCu, or 3-12 wt% Contact material. The method according to claim 1,
Wherein the silver-oxide composite material is an oxide including tin oxide, tin-indium oxide, zinc oxide, or bismuth oxide. The method according to claim 1,
Wherein the silver-oxide composite material comprises a silver matrix and oxide particles distributed in the silver matrix. The method of claim 3,
Wherein the oxide particles have an average particle diameter of 0.1 to 0.7 占 퐉. The method according to claim 1,
Wherein the positive (+) contact is located on the surface of the positive (+) contact and comprises an oxide layer comprising 20 to 60 wt% oxide. 6. The method of claim 5,
Wherein the thickness of the oxide layer is 1 to 30 占 퐉. The method according to claim 1,
Wherein the negative (-) contact comprises AgNi, and Ni comprises greater than 0 wt% and not greater than 30 wt%. The method according to claim 1,
Wherein the negative (-) contact comprises AgCu, and Cu comprises greater than 0 wt% and not greater than 60 wt%. The method according to claim 1,
Wherein the negative (-) contact comprises a silver-oxide composite material, and the silver-oxide composite material of the negative electrode contact comprises 5 to 10% by weight of an oxide and the balance of Ag.

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