RU128541U1 - DEVICE FOR DIFFUSION WELDING OF METALS WITH NON-METALS BY METHOD OF ELECTRICALLY EXPLOSABLE INTERMEDIATES IN VACUUM - Google Patents

Abstract

A device for connecting parts by diffusion welding using an electrically exploded conductor, characterized in that it contains a vacuum chamber and a pumping system designed to install the connected parts and the explosive conductor placed between them, a pressure mechanism that provides the application of compressive pressure to the connected parts, and also a power source and a high-voltage pulse capacitor with the possibility of obtaining a discharge of a pulse current with a power of 5-10 kJ, providing an explosion of wire arrestor to form a joint area of nanostructure materials of the parts and explodable conductor.

Description

Utility model - a device for diffusion welding is mainly used to obtain a strong connection of two or more metal bodies. Nevertheless, the development and improvement of modern electronics in instrumentation, aviation and other industries cannot be imagined without the use of new structural materials based on ceramics, ceramic, quartz, ferrite and other non-metallic materials. These materials are based on oxides of various elements and have unique physicochemical properties.

Compounds of these materials with metals and with each other widely

they are used for fastening elements of high-frequency systems, for viewing and waveguide windows, shells and cases of electronic and gas-discharge devices, for photocathodes in night-vision devices, laser gyroscope cases, in accelerator technology, in the manufacture of jewelry, etc. Traditional methods for producing such compounds are gluing and soldering - far from always provide high strength, vacuum density, heat resistance, reliable thermal and electrical contact, preservation of properties during long-term storage.

Promising methods for joining dissimilar materials with special physical and mechanical properties at low temperature and pressure - welding using electrically exploded interlayers

A known method of welding: welding by pulsed electric discharge in a liquid (SIEC) invention Yutkina L.A. A.A. Deribas, V.M. Kudinov, F.I. Matvienkov. [copyright certificate SU No. 1309404, No. 1600101]. (The author cites excerpts from the book A. A. Yutkin “Electro-hydraulic effect” 1955 Moscow-Leningrad “Mashgiz.” Circulation 6 500.)

The essence of the electrodynamic effect is that during a high-voltage pulse discharge in a liquid around a discharge zone, pulsed ultrahigh pressures arise in the form of a shock wave in a liquid that deforms plastic and destroys brittle objects near the discharge zone.

A pulsed electrical discharge within the fluid volume is carried out by a pulsed current generator consisting of a high voltage transformer, a rectifier, a capacitor bank, and a switch. The interelectronic gap in the liquid is closed by a metal wire. When a pulsed discharge current is passed through such a wire, a phenomenon occurs called an electric explosion of the conductor.

The disadvantage of this method can be a significant width of the layer leads to the formation of defects in the joint, to obtain the finished adapter requires mechanical processing.

A known method of diffusion welding in vacuum [copyright certificate SU No. 1303335 dated 12.24.85], which allows to heat-weld dielectrics and semiconductors with metals or with each other. A semiconductor wafer made of a material with negative differential conductivity with metallized contact surfaces is mounted on the surface of the parts to be welded from a dielectric or semiconductor, opposite to the one being welded. The parts are heated, squeezed and high voltage is applied to them through the semiconductor wafer, under the influence of which the semiconductor wafer begins to generate high-frequency and ultrasonic vibrations commensurate with the frequency of atomic vibrations in the lattice of the materials being welded, which activate the process.

The disadvantage of this method is the bulkiness of the installation and the insufficient level of quality of the connections.

A known method of diffusion welding of porous materials through a metal interlayer [certificate of authorship SU No. 1750897 dated 05/11/90], which allows a gaseous organometallic substance to be pumped between the surfaces of the porous materials cooled to minus temperatures, during which pyrolysis forms a metal interlayer on the surfaces to be welded. Then the parts are heated from the outside and, after the cessation of the vapor-gas mixture, is squeezed and isothermal exposure is performed. In the welding process, the connection of parts begins from their periphery to the center.

The disadvantage of this method is the limited application. Significant cost of implementation time.

The closest analogue (prototype) of the considered solution can be considered a device for diffusion welding using an electrically exploded conductor [patent: RU 82438 U1, from 04/27/2009]

Description: The combination of materials using an electric explosion of interlayers in vacuum (SVzPV) allows us to solve these problems.

The device allows you to implement the principle of models and nanotechnologies for connecting structural non-metals with metals and non-metals through electrically exploded interlayers in a vacuum.

The essence of the utility model is that a device with a variable resistance is used for an electric explosion of conductors. The device is compactly housed in a single independent module and consists of a power source 1, a high-voltage pulse capacitor 2, a circuit breaker 3, and a charging resistance 4 mounted on a stand in the module, directly near the vacuum chamber 7. The pumping system 8 is also installed on the module to create preset vacuum purity in the working chamber. A pressure mechanism 9 is located above the vacuum chamber to create the necessary pressure in the vacuum chamber 7. Weldable parts 6 are fixed inside the vacuum chamber 7 so that the exploding conductor 5 connected through the contactor 3 to the power source is sandwiched between the parts to be welded 6 by the pressure mechanism 9.

A diagram of a device for exploding an interlayer in a vacuum is shown in FIG. 1

Scheme for welding using an electric explosion of conductors:

1 - power source

2 - high voltage pulse capacitor,

3 - circuit breaker,

4 - charging resistance;

5 - exploding conductor,

6 - welded parts,

7 - vacuum chamber,

8 - pumping system,

9 - pressure mechanism.

The device operates as follows: from an external power source, the power source 1 is charged. The pumping system 8 creates a vacuum of a given depth in the vacuum chamber 7 to carry out the work. The pressure mechanism 9 creates a predetermined pressure between the parts to be welded 6, (an exploding conductor 5 is placed between them). After that, the device is disconnected from the power source and further work occurs regardless of external influences. When checking the achievement of the set parameters of the installation using the control devices mounted on the module, the circuit breaker 3 is turned on. The current passes from the power source into the vacuum chamber 7 to the exploding conductor 5. As a result, the conductor 5 explodes and the pressure created after the explosion by mechanism 9 in the vacuum diffuses parts to be welded 6.

The temperature and time regime of an electric explosion in a device determines the nanostructure of materials in the joint zone.

The constructed device allows using the average temperature of the interlayer during the explosion, depending on the material of the interlayer and the parameters of the discharge circuit: capacitor capacitance, circuit inductance, interlayer dimensions. High temperatures (up to 30000 K) and short times (microseconds) ensure the formation of a nanostructure from the materials of the parts to be connected and the exploding conductor in the joint zone.

This provides the opportunity when using SVzPV to obtain high-quality compounds of metals and non-metals, as well as non-metals with non-metals (ceramics + ferrites, glass + quartz glass, ruby + ruby, etc.). The device can be used, for example, with a residual pressure in a vacuum chamber of 10 ^-4 Pa, a welding pressure of 20 ... 30 MPa and a temperature of parts of 500 ... 600 K.

The proposed device for connecting materials (metals with metals, metals with non-metals and non-metallic materials to each other) comprising heating the materials to be welded in a vacuum of 10 ^-2 -10 ^-3 Pa (pascal), primary heating to 200-300 ° C in a vacuum followed by passing through a metal layer selected by the physicochemical properties close to the materials to be joined, a pulsed current with a power of 5-10 kilo joules due to the discharge of a capacitor, characterized in that the pulsed current provides heating of the interlayer to a temperature of the formation of molten clusters, which, when combined, form a discontinuous cluster that destroys the interlayer, with the formation of a nanostructure of the materials of the parts to be connected and an explosive interlayer with a characteristic sound signal, such as an explosion, and stopping the flow of current, immediately after this, compressive pressure is applied to the connected parts, the parts in the chamber cooled to room temperature, this process ensures the formation of high-quality compounds by adjusting the crystal lattices of the compound hired parts with each other.

A device for connecting parts of diffusion welding using an electrically exploded conductor, characterized in that it contains a vacuum chamber and a pumping system designed to install the parts to be connected and the explosive conductor placed between them, a pressure mechanism that provides compressible pressure to the parts to be joined, and also a power source and a high-voltage pulse capacitor with the possibility of obtaining a pulse current discharge with a power of 5-10 KJ, providing an explosion of wire nick to form at the junction of nanostructure materials of the parts and explodable conductor.

Claims (1)

A device for connecting parts by diffusion welding using an electrically exploded conductor, characterized in that it contains a vacuum chamber and a pumping system designed to install the parts to be connected and the explosive conductor placed between them, a pressure mechanism that provides compressive pressure to the parts to be joined, and also a power source and a high-voltage pulse capacitor with the possibility of receiving a discharge of a pulse current with a power of 5-10 kJ, providing an explosion of wire arrestor to form a joint area of nanostructure materials of the parts and explodable conductor.

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