Method using vacuum brazing device to braze aluminum alloy workpiece

Abstract

The invention discloses a vacuum brazing device which improves the brazing performance and quality of an aluminum and aluminum alloy workpiece and a method using the device to braze an aluminum alloy workpiece. The vacuum brazing device comprises a magnesium vapor generating chamber, a brazing chamber and a magnesium collecting chamber, wherein the magnesium vapor generating chamber, the brazing chamber and the magnesium collecting chamber are hermetically communicated with each other through a pipe; and the magnesium vapor generating chamber is internally provided with an electric heating device and the magnesium collecting chamber is internally provided with a collecting copper net with a cooling water pipeline. During brazing, pure magnesium is placed on the electric heating device, the workpiece and the brazing filler metal are placed in the brazing chamber, and then the vacuum brazing device is placed into a vacuum brazing furnace integrally; the oxide film on the surface of the aluminum alloy workpiece is thoroughly removed by flow of magnesium vapor according to different vapor pressures of magnesium in the three chambers, so that the brazing deficiencies such as crack, oxide inclusion, insufficient brazing and non-brazing and the like in the brazing position of the aluminum alloy workpiece in a complex structure can be strictly controlled, thereby, improving the brazing performance and quality of the aluminum alloy brazing workpiece to a great extent.

Description

technical field [0001] The invention relates to the field of aluminum and aluminum alloy welding, in particular to a vacuum brazing device for aluminum and aluminum alloy workpieces, and also relates to a method for using the device to braze aluminum alloy workpieces. Background technique [0002] Aluminum alloy has the advantages of low density, high strength, good plasticity, strong formability, electrical conductivity, excellent thermal conductivity, and good corrosion resistance. It is widely used in industry, and its usage is second only to steel. Aluminum alloy refers to the general term for a class of alloys based on aluminum elements. The main alloying elements added are copper, silicon, magnesium, zinc, and manganese, and the secondary alloying elements are nickel, iron, titanium, chromium, lithium, etc. Aluminum alloys are mainly divided into two categories according to processing methods: cast aluminum alloys (used in cast state) and deformed aluminum alloys (can ...

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Problems solved by technology

Its disadvantages are as follows: First, since the heating of the workpiece and the removal of the oxide film are carried out by molten salt, it is difficult to enter and exit the salt for the workpiece with a complex structure, which limits the structural design and processing technology, making it It is complicated, and it is not easy to guarantee the welding quality; secondly, due to the specific use environment and service life requirements, some products have relatively high corrosion resistance requirements, and a large amount of flux remains in the workpiece after salt bath brazing, which requires a long time Cleaning time; In addition, salt bath brazing equipment has a large investment, complex process, and long production cycle

However, for aluminum alloy brazing parts with complex structures (such as aluminum alloy radiators, condensers, exhaust pipes, etc.), magnesium vapor is difficult to spread on the brazing interface, and brazing products often have cracks, Welding defects such as oxide slag inclusions, virtual welding, and lack of welding make the yield of aluminum alloy brazing products low

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