SU1107184A1 - Cermet bimetallic electric contact - Google Patents

Abstract

METAL-CERAMIC BIMETALLIC ELECTRIC CONTACT, whose contact element is made with a working layer of silver-based material and a sublayer of copper-nickel alloy, characterized in that, in order to increase the strength of attachment of the contact element to the contact holder, the sublayer of the contact element additionally contains iron and titanium the following ratio of ingredients, May.%: Nickel 4.0-9.0 Titanium 1.0 - 3.0 Iron 30.0-75.0 Copper Rest (L

Description

G 4 The invention is in the field of electrical engineering, in particular, bimetal electrical contacts, and is intended for use in electrical equipment engineering and mechanical engineering, including in conditioning structures in low-voltage electrical equipment. The electrical bimetallic contact tl is known, which contains a working olay of silver-based alloy and a base layer of copper-based alloy with additives May.%: Nickel 10-20 Zinc 10-30 Yttrium 0.01-0.5 Copper Else However, although the contact It has a long service life, but its electrical conductivity is low. Metal-ceramic bimetallic electrical contact is known with a working layer of silver-containing material and a copper-nickel alloy underlayer containing 10–25 wt.% Nickel, the rest is 2 J. The disadvantage of this contact is the poor weldability of the contact underlayer with the contact holder. The closest to the invention to the technical essence is a metal-thermal bimetallic electrical contact, the contact element of which is made with a silver-based working layer and a sublayer of copper-nickel alloy Z. A disadvantage of the known contact is the insufficient strength of attachment of the contact element to the contact holder. The purpose of the invention is to increase the strength of attachment; t the contact element to the contact containment. The goal is achieved by the fact that in metal-ceramic bimetallic electrical contact, the contact element of which is made with a working layer of silver-based material and a sublayer of a copper-nickel alloy, the sublayer of the contact element also contains iron and titanium in the following ratio of ingredients, wt.%: Nickel4.0 - 9.0 Titan1.0 - 3.0 Iron 30, 0-75, L Copper Else To obtain the proposed bimetallic contacts, five mixtures of ingredients for a sublayer (50 g each) listed in Table 1 were prepared. Table 1

2

0.5 25

Rest

Each mixture is prepared separately by mixing, in dry form, starting powders with a particle size of not more than 50 microns in a vibrating mill with 9 mm dia N eTpoM balls, two times the mass of the mixture for 2 hours. Silver nickel - graphite of the type СН29 МГ2 is used as a working contact layer.

Contact samples of the type СН29Т1Г2 with dimensions of 13-13-2.4 mm with five sublayer compositions, indicated in table.1, i, are pressed at a pressure of 2.5 + 0.5 tf / cm. Sintering of the samples was carried out at 860 t 10 ° C for 2 hours in vacuum. Sintered

6.5

12

9.0 2

4.0

3

80 50

75

Ostal-Ostal-Ostal-Ost

Samples are pressed with a pressure of 6 i 0.5 tf / cm, after which they are re-sintered in the specified mode. The sintered samples are calibrated with a pressure of 10 + 0.5 ts / cm, after which they are annealed at 450 ° C for 0.5 h in a vacuum of 10 Torr.

The mechanical strength of the adhesion of the working layer of contacts of the type SN29MG2 with its sublayer of the proposed

material estimated by crimping

contacts in diameter on the press between the plates.

In tab. 2 shows the results of tests of contacts after deforming them by 50% in diameter.

31107184

Table2: Test results of the contacts 1 The tests did not stand, cracks between the sublayer and the contact body appeared, 2 The test passed 3 The same 4 5 The test did not stand, the cracks between the sublayer and the contact body showed As a result of the tests, it was established that the adhesion strength of the proposed working layer contact with its sublayer is high, In table. Table 3 shows the physical properties of contacts of the type СН29МГ2 with a sublayer of the proposed material as well as the strength of their soldering by solder PС4545 to copper contact holders in comparison with the strength of soldering of known contacts. Table Numerical Properties of the value of PROPERT

Continued table. 3 Specific resistivity of samples, Ohm Average values of shear forces, kg / mm along the border; body of contact - proposed sublayer; proposed sublayer; contact holder; known contact contact holder. From the data in Table 3 it follows that the contacts made from the material proposed have high physical characteristics and strength of attachment to contact holders is higher than that of the known one. The proposed electrical contacts can be used in the electrical, engineering and other industries of the industry for the manufacture of circuit breakers instead of the currently used contacts of the type СН29МГ2 with a silver sublayer. The expected technical and economic effect from the use of the invention as compared with the base object, a contact of the type SN29MG2 with a silver sublayer, is that it provides an increase in the strength of attachment of the contact to the contact carrier, increases the corrosion resistance of the sublayer, increases the reliability of the contact unit and saves silver. Replacing the contacts of the СН29МГ2 type with the silver sublayer used in automatic switches of the L3700 series with the proposed contacts of the СН29МГ2 type with the base layer of the base metal alloy provides silver savings in the amount of about 80 kg per one contact.

Claims (1)

METALLO-CERAMIC BIMETALLIC ELECTRIC CONTACT, the contact element of which is made with a working layer of silver-based material and a sub-layer of copper-nickel alloy, characterized in that, in order to increase the strength of fastening of the contact element to the contact holder, the sub-layer of the contact element additionally contains iron and titanium in the following ratio of ingredients, May: Nickel 4.0 - 9.0 Titanium 1.0 - 3.0 Iron 30.0-75.0 Copper Rest metal-ceramic bimetallic electrical contact, the contact element of which is made of a layer based on silver and from a copper-nickel alloy