SU1511033A1 - Method of brazing aluminium and alloys thereof - Google Patents

Abstract

The invention relates to soldering, in particular to the soldering of aluminum in magnesium vapor, and can be used in various fields of engineering. The purpose of the invention is to increase the corrosion resistance of steam products, simplify equipment and increase productivity by carrying out the process with less vacuum. Parts are assembled with placement in an aluminum-based brazing zone. Place the parts in a collapsible non-hermetic container that has pumping holes. From the outside of the container in the area of the pumping holes, the source of magnesium vapor is placed. Cover the vapor source with a titanium sponge. The container is installed in a vacuum chamber, vacuuming, heating to soldering temperature, holding and cooling are carried out. Magnesium vapor partially penetrates into the container and improves the flow of solder without deteriorating the corrosion resistance of the product, and most of them, together with the titanium sponge, work as a getter and provide wetting of parts with solder at a residual pressure of not higher than 13.3 Pa.

Description

The invention relates to soldering, in particular to the soldering of aluminum in magnesium vapor, and can be used in various fields of engineering.

The purpose of the invention is to increase the corrosion resistance of steam products, simplify equipment and increase productivity by carrying out the process with less vacuum.

The method is carried out as follows.

Parts are assembled with placement in an aluminum-based brazing zone. Parts are placed in a collapsible non-hermetic container that has pumping holes, and placed from the outside.

container in the area of the pumping holes a source of magnesium vapor, cover the source of vapor with a titanium sponge, install the container in a vacuum chamber, carry out a vacuum, heat to soldering temperature, hold and cool.

When soldering in this way, the wetting and spreading of the solders based on aluminum on aluminum and its alloys is provided with their slight overheating above the liquidus temperature. The use of a container with evacuating holes sealed with a titanium sponge allows not only to limit the volume of the gaseous medium interacting with the brazed surfaces and solder, and to remove from the container

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gases that are under excess pressure relative to the entire evacuated volume, but change the composition of the gases flowing into the container through the titanium sponge, in a direction that is favorable for the activation of the melted aluminum surface. Magnesium, located between the holes and the titanium sponge layer, begins to evaporate at 520-540 ° C. Pairs of magnesium, performed the role of a getter simultaneously with the titanium-mechanical tests of strength specimens. A comparative analysis showed that when brazing in an unpressurized container without sealing the gate with magnesium and a titanium sponge, there is practically no spreading of solder, whereas when soldering, according to this method, stable flow of solder is observed (spreading area of 800-900 mm), wetting angle O-1 °) and obtaining high-quality solder joints with a sponge makes it possible to provide with a more than 10 comparable to the strength of basic and thorough cleaning of the pale atmosphere from acid metal 100-120 MPa. improving conditions for activating the aluminum surface. At the same time

part of the magnesium vapor getting inside

The use of this method of soldering aluminum and its alloys using solder on a container interacts with aluminum in pairs with magnesium, providing aluminum and its oxides, in comparison with the known method of surface activation due to dispersions, the elimination of the high-vacuum modulation of the oxide film .

Example. Experiments were carried out to determine the spreading and soldering of strength T-specimens. The sample material is 20 additional purification of the atmospheric atmosphere by the AMts alloy, the solder is the eutectic force using the specified diamine circuit. Strength specimens are made of 4 mm thick sheet with a cross section of the working part of 15X4 mm, the value of the gap is 0.05 mm. Samples for spreading are made of 15 mm thick sheet. Samples and solder were degreased with alcohol, etched in an alkaline solution standard for aluminum alloys, washed, clarified, washed, and dried. Solder blanks for soldering strength specimens and scans. All this significantly affects the spreading of the samples. They were cut from the rod. The samples collected for soldering were placed in a collapsible container with a shutter, which was compacted with a crushed titanium sponge.

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due to soldering in a collapsible vacuum chamber using only a mechanical pump, the addition of magnesium, which reduces the amount of magnesium to activate the aluminum surface from 0.1 to 0.01 g per liter of container volume and deposition on the chamber wall, as well as enhances the corrosion resistance of steam products. In addition, soldering in a heat-treatment furnace allows the use of forced cooling of vacuum-evacuated gels.

Claims (1)

Invention Formula having previously placed under it hinge plates The method of soldering aluminum and its alloys. Magnesium at the rate of 0.01 g per liter of volume of 35 pp which assembles parts from the main container. The container was made from the location in the soldering zone of stainless steel. The container with the samples was loaded into a collapsible evacuated tube-container and the latter was placed in a CHO-type thermal furnace. Soldering was carried out at a residual pressure of 13.3 Pa, created in the container pipe using a mechanical vacuum pump according to the mode: heated to a soldering temperature of 600 ° C at a rate of 30 ° C / min, holding 10 minutes. put the parts in a collapsible unsealed container with pumping holes, place the container with a source of magnesium vapor in the vacuum chamber, perform vacuuming, heat the parts to the brazing temperature, hold and cool down, in order to increase the corrosion resistance steam products, simplify equipment cooling with a stove. For comparative analysis and increase of productivity of the analysis, the same samples were made in the wrong process with a smaller collapsed container without a shutter, the source of magnesium vapor is placed in the same mode. Magnesium was placed inside the outside of the container in a regional container. The contact angle of the wetting holes was determined and covered its standings and the spreading area. Made with a methane sponge. Changes in strength tests. A comparative analysis showed that when brazing in an unpressurized container without sealing the gate with magnesium and a titanium sponge, there is practically no spreading of solder, whereas when soldering, according to this method, stable flow of solder is observed (spreading area of 800-900 mm), wetting angle O-1 °) and obtaining high-quality solder joints with thorough cleaning of the steam atmosphere using the specified plowing scheme due to soldering in a collapsible vacuumized chamber using only a mechanical pump, domers. All this significantly affects the magnesium, which reduces the amount of magnesium to activate the aluminum surface from 0.1 to 0.01 g per liter of container volume and deposit it on the chamber wall, as well as increase the corrosion resistance of the vapor products. In addition, soldering in a heat-treatment furnace allows the use of forced cooling of the vacuumized chamber. All this is significantly influenced. performance improvement. Invention Formula ry All this significantly affects the The method of soldering aluminum and its alloys. put the parts in a collapsible unsealed container with pumping holes, place the container with a source of magnesium vapor in the vacuum chamber, perform vacuuming, heat the parts to the brazing temperature, hold and cool down, in order to increase the corrosion resistance equipment, simplify equipment and increase productivity by carrying out the process with less dilution, the source of magnesium vapor is placed on the outside of the container in the area of the discharge holes and okryvat his five- thanes sponge.