WO2012014949A1 - Electric contact material - Google Patents

Abstract

In silver-oxide electric contact materials, there has been the problem of oxides being deposited on the contact surface by repeated electrical opening/closing, resulting in contact resistance at the contact surface and causing a temperature increase. Therefore, the disclosed electric contact material is characterized by forming at least one of 1-99 mass% Ag-W, 1-99 mass% Ag-WC, W or WC as at least one coating layer on the contact surface of the silver-oxide electric contact material.

Description

Electrical contact material

The present invention relates to an electrical contact material used for an electromagnetic switch such as a magnet switch, a breaker, or a relay.

Conventional silver-oxide-based electrical contact materials are subject to performance problems by changing internal oxidation conditions and adding third and fourth elements to improve welding resistance, wear resistance, and temperature characteristics. Has been overcome. For example, there is a material in which Sn, In, Sb, Bi, or the like is added to Ag and subjected to internal oxidation treatment (see, for example, Patent Document 1).

Further, it contains Sn: 4 to 11%, In: 1 to 5%, Te: 0.05 to 3%, Cd: 0.05 to 3% in mass (mass)%, and if necessary, Fe, One or more of Ni and Co: 0.01 to 1%, and an Ag alloy having a structure composed of Ag and inevitable impurities with the remainder being subjected to internal oxidation treatment has been proposed (see, for example, Patent Document 2) ).

JP 2002-363665 A Japanese Patent Laid-Open No. 5-86426

However, in the conventional technology described above, the silver-oxide-based electrical contact material repeats electrical switching, and oxide is deposited on the contact surface layer, which increases the contact resistance on the contact surface. There is a problem of causing a temperature rise.

In order to solve this temperature increase problem, there is a method of reducing the amount of oxide to be added. However, if the amount of oxide to be added is reduced, there is a problem that welding resistance and wear resistance are lowered. is there.

Obtaining stable contact resistance and achieving excellent temperature characteristics and improving welding resistance and wear resistance are contradictory, and are often a problem in selecting contact materials.
An object of the present invention is to solve such a problem.

Accordingly, the present invention provides a contact surface of a silver-oxide based electrical contact material with at least one of 1 to 99 mass% Ag-W, 1 to 99 mass% Ag-WC, WC or W having a thickness of 0.1 μm to 1000 μm. By applying this coating, the resistance value of the contacts is lowered to eliminate abnormal temperature rises, and the welding resistance and wear resistance are greatly improved, and even when used as an electrical contact material for high loads. It was able to be a contact point of life.

As an example, FIG. 18 shows a structure photograph of a contact obtained by coating W on a contact material of 91.7Ag-5.5SnO ₂ -2.5In ₂ O ₃ -0.3NiO.

Further, at least one coating of Pt, Au, Ag, Ni and Cu is applied between the electrical contact material and the coating layer of 1 to 99 mass% Ag-W, 1 to 99 mass% Ag-WC, WC or W. Can reduce the resistance value of the contacts, prevent abnormal temperature rise, and greatly improve welding resistance and wear resistance, even when used for high load electrical contact materials It can be a long-life contact.

The coating method includes plasma spraying, gas spraying, high-speed flame spraying, and other spraying, intermittent discharge in the air and liquid as shown in FIGS. By vapor deposition methods such as PVD and CVD.

In the above, the reason why the thickness of one layer of the coating layer is in the range of 0.1 μm to 1000 μm is that when the thickness of one layer is less than 0.1 μm, there is no coating effect. In addition, if the thickness of one layer exceeds 1000 μm, it is difficult to perform coating from the viewpoint of technology and production cost.
In addition, in 1 to 99 mass% Ag-W and 1 to 99 mass% Ag-WC, if the Ag component is less than 1 mass% and exceeds 99 mass%, the meaning of the Ag alloy is lost.

In the present invention as described above, by coating the silver-oxide based electrical contact material with the above configuration, the resistance value of the contact can be lowered, the welding resistance and the wear resistance can be improved, and the life can be extended. It becomes.

In addition, by applying at least one coating of Pt, Au, Ag, Ni, Cu between the electrical contact material and the coating layer, the resistance value of the contact can be further lowered, preventing abnormal temperature rise, Even when used as an electrical contact material for high loads due to significantly improved welding resistance and wear resistance, it is possible to extend the service life.

Schematic illustration of coating by air discharge Schematic illustration of coating by submerged discharge Schematic illustration of single layer coating Schematic illustration of partial coating Schematic explanatory diagram of Example 9 Schematic explanatory diagram of Example 10 Schematic explanatory diagram of Example 11 Schematic explanatory diagram of Example 12 Schematic explanatory diagram of Example 13 Schematic explanatory diagram of Example 14 Schematic explanatory diagram of Example 15 Schematic explanatory diagram of Example 16 Schematic explanatory diagram of Example 17 Schematic explanatory diagram of Example 18 Schematic explanatory diagram of Example 19 Schematic explanatory diagram of Example 20 Schematic explanatory diagram of Example 21 Photo of cross-sectional structure of coated contact

Embodiments according to the present invention will be described below with reference to the drawings.
First, 91.7 mass% Ag-5.5 mass% Sn-2.5 mass was internally oxidized for 48 hours at a plate thickness of 1.2 mm, a 3.5 mm square oxygen partial pressure of 0.5 MPa, and an internal oxidation temperature of 700 ° C. A contact material made of% In-0.3 mass% Ni is prepared.

The contact material was coated with 1 mass% Ag-W by air discharge (see FIG. 1) to form a layer thickness of 800 μm.

The air discharge conditions were as follows: 1 mass% Ag-W for the anode and 91.7 mass% Ag-5.5 mass% Sn-2.5 mass% In-0.3 mass% Ni for the cathode were connected to the atmosphere. The coating layer 4 was applied as shown in FIG. 3 by oscillating at a current of 1 to 3 A, voltage of 60 V, discharge distance of 1 mm, and 300 to 400 Hz.
In FIG. 1, 1 is an electrode and 2 is a contact.

Moreover, although it carried out by the air discharge in the above, it may be a liquid discharge. As shown in FIG. 2, the contact 2 is placed in a general electrolyte 3 such as a tricalcium phosphate solution or a 5% citric acid aqueous solution. Discharge is performed with the electrode 1.

The contact material was coated with 1 mass% Ag-WC by air discharge (see FIG. 1) to form a layer thickness of 100 μm.

The air discharge conditions are as follows: 1 mass% Ag-WC is connected to the anode, and 91.7 mass% Ag-5.5 mass% Sn-2.5 mass% In-0.3 mass% Ni contact material is connected to the cathode. Then, a partial coating layer 4 was applied as shown in FIG. 4 by oscillating at a current of 1 to 3 A, a voltage of 60 V, a discharge distance of 1 mm, and a discharge of 300 to 400 Hz, and intermittently discharging.

The surface of the contact material was blasted and then coated by plasma jet spraying.

The plasma jet spraying conditions are as follows: Ag powder having a particle size of 5 to 125 μm and W powder are mixed in a plasma jet atmosphere so as to have a ratio of 50: 1. In the atmosphere, a jet current of 500 to 800 A, a spraying distance of 100 mm, plasma Argon is used as the gas (flow rate 30 l / min), and the spray gun is reciprocated at 300 mm / sec to coat the coating layer 4 with a thickness of 0.1 μm and a coating layer 4 composition of 50 mass% Ag-W. Layered.

The coating layer 4 was applied by plasma spraying similar to Example 3 with a coating layer 4 thickness of 20 μm and a coating layer 4 composition of 50 mass% Ag-WC.

The coating layer 4 was applied by plasma spraying in the same manner as in Example 3 with the thickness of the coating layer 4 being 500 μm and the composition of the coating layer 4 being 99 mass% Ag—W.

The coating layer 4 was applied by plasma spraying in the same manner as in Example 3 above, with the coating layer 4 having a thickness of 1000 μm and the composition of the coating layer 4 being 99 mass% Ag-WC.

The coating layer 4 was applied by plasma spraying similar to Example 3 with the coating layer 4 having a thickness of 300 μm and the composition of the coating layer 4 being W.

The coating layer 4 was applied by plasma spraying similar to Example 3 above with the coating layer 4 having a thickness of 600 μm and the composition of the coating layer 4 being WC.

The thickness of one coating layer is set to 50 μm by plasma spraying similar to that in Example 3, and the composition of the coating layer is alternately 1 mass% Ag-W and 1 mass% Ag-WC from the bottom as shown in FIG. Eight coating layers 4 were applied.

The thickness of one coating layer is 50 μm by plasma spraying similar to Example 3, and the composition of the coating layer is alternately 50 mass% Ag-W and 50 mass% Ag-WC from the bottom as shown in FIG. Six coating layers 4 were applied.

The thickness of one coating layer is 50 μm by plasma spraying similar to Example 3, and the composition of the coating layer is alternately 99 mass% Ag-W and 99 mass% Ag-WC from the bottom as shown in FIG. Four coating layers 4 were applied.

The thickness of one layer of the coating layer was set to 50 μm by plasma spraying similar to Example 3 described above, and the two coating layers 4 were applied as W and WC from the bottom as shown in FIG.

91.7 mass% Ag-5.5mass% Sn-2.5mass% In, which was internally oxidized for 48 hours at a plate thickness of 1.2mm, dimensions of 3.5mm square, oxygen partial pressure of 0.5MPa, and internal oxidation temperature of 700 ° C. After blasting the surface of the contact material made of -0.3 mass% Ni, a coating layer was applied by plasma jet spraying.

Plasma jet spraying was performed under the same conditions as in Example 3 above. Ag powder and W powder having a particle size of 5 to 125 μm were mixed in the plasma jet atmosphere so that the ratio was 99: 1, and the amount of W powder was gradually increased. Then, the composition is changed step by step, the thickness of one coating layer is 100 μm, and the composition of the coating layer is 99 mass% Ag-W, 75 mass Ag-W, 50 mass% Ag− from the bottom as shown in FIG. The coating layer 4 was applied as W, 25 mass% Ag-W, and 1 mass% Ag-W.

In the same manner as in Example 13, the thickness of one coating layer was 100 μm, and the composition of the coating layer was 99 mass% Ag-WC, 75 mass% Ag-WC, 50 mass% Ag— from the bottom as shown in FIG. The coating layer 4 was applied as WC, 25 mass% Ag-WC, and 1 mass% Ag-WC.

91.7 mass% Ag-5.5mass% Sn-2.5mass% In, which was internally oxidized for 48 hours at a plate thickness of 1.2mm, dimensions of 3.5mm square, oxygen partial pressure of 0.5MPa, and internal oxidation temperature of 700 ° C. After blasting the surface of the contact material made of -0.3 mass% Ni, a coating layer was applied by plasma jet spraying.

Plasma jet spraying was performed under the same conditions as in Example 3 above. The thickness of one coating layer was 50 μm, and the composition of the coating layer was 1 mass% Ag—W and Au from the bottom as shown in FIG. The five coating layers 4 were applied alternately.

In the same manner as in Example 15, the thickness of one coating layer is 40 μm, and the composition of the coating layer is 7 coating layers alternately as 1 mass% Ag—W, Au, and Pt from the bottom as shown in FIG. 4 was applied.

In the same manner as in Example 15, the thickness of one coating layer is 50 μm, and the composition of the coating layer is 50 mass% Ag—W and Au from the bottom as shown in FIG. gave.

In the same manner as in Example 15 above, the thickness of one coating layer is 40 μm, and the composition of the coating layer is seven coating layers alternately as 50 mass% Ag—W, Au and Pt from the bottom as shown in FIG. 4 was applied.

In the same manner as in Example 15, the thickness of one coating layer is 20 μm, and the composition of the coating layer is 99 mass% Ag—W and Au from the bottom as shown in FIG. gave.

In the same manner as in Example 15, the thickness of one coating layer is 20 μm, and the composition of the coating layer is 10 coating layers alternately as 99 mass% Ag-WC, Au and Pt from the bottom as shown in FIG. 4 was applied.

In the same manner as in Example 15, the thickness of one coating layer was 10 μm, and the composition of the coating layer was composed of 9 layers of 99 mass% Ag—WC and Ni, Ag and Cu alternately from the bottom as shown in FIG. Coating layer 4 was applied.

Comparative Example 1

91.7 mass% Ag-5.5mass% Sn-2.5mass% In, which was internally oxidized for 48 hours at a plate thickness of 1.2mm, dimensions of 3.5mm square, oxygen partial pressure of 0.5MPa, and internal oxidation temperature of 700 ° C. A contact made of −0.3 mass% Ni was produced.

Comparative Example 2

92.3 mass% Ag-5 mass% Sn-2.5mass% In-, which was 1.2 mm thick and 3.5 mm square with an oxygen partial pressure of 0.5 MPa and an internal oxidation temperature of 700 ° C. for 48 hours. A contact made of 0.2 mass% Ni was produced.

Comparative Example 3

91.9 mass% Ag-7 mass% Sn-1 mass% In-0.1 mass which was internally oxidized for 48 hours at a thickness of 1.2 mm, dimensions of 3.5 mm square, oxygen partial pressure of 0.5 MPa, and an internal oxidation temperature of 700 ° C. A contact made of% Ni was prepared.

The contact test was conducted for each of the above examples and comparative examples. The contact test was performed by measuring contact resistance, welding test (for 60A rating), and measuring consumption by a commercially available contactor (AC200V, 20A) to evaluate electrical characteristics.

[Supplement under rule 26 08.09.2011]

1 electrode 2 contact 3 electrolyte 4 coating layer

Claims (4)

One or more kinds of 1 to 99 mass% Ag-W, 1 to 99 mass% Ag-WC, W or WC are formed as one or more coating layers on the contact surface of the silver-oxide based electrical contact material. Electrical contact material. 2. The electrical contact material according to claim 1, wherein the thickness of one coating layer is 0.1 μm to 1000 μm. The electrical contact material according to claim 1, wherein a plurality of coating layers are formed in which the amount of Ag of 1 to 99 mass% Ag-W or 1 to 99 mass% Ag-WC is changed stepwise. 2. The method according to claim 1, wherein at least one coating layer of Pt, Au, Ag, Ni, Cu is provided between the coating layers of 1 to 99 mass% Ag—W or 1 to 99 mass% Ag—WC. Electrical contact material.

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