Laser-double TIG electric arc composite self-fluxing brazing method for aluminum alloy and stainless steel

Abstract

The invention discloses a laser-double TIG electric arc composite self-fluxing brazing method for aluminum alloy and stainless steel. The laser-double TIG electric arc composite self-fluxing brazing method comprises the steps that a laser beam-double TIG electric arc composite heat source is adopted for welding a lap joint of an aluminum alloy plate on the upper portion and stainless steel on the lower portion, the aluminum alloy is melted through the composite heat source, the stainless steel is heated, and a brazing interface is formed. A laser beam is a variable power pulse scanning laser beam; the double TIG electric arc comprises a positive polarity TIG electric arc and a reverse polarity TIG electric arc; the direct-current reverse connection TIG welding gun and the direct-current forward connection TIG welding gun are located on the front side and the rear side of the laser beam in the welding direction correspondingly. In the welding process, the laser beam scans the surface of a workpiece to be welded, it is guaranteed that 2/3-3/4 laser heat is on the aluminum alloy plate, 1/3-1/4 laser heat is on a stainless steel plate, the direct-current reverse connection TIG welding gun and the direct-current forward connection TIG welding gun conduct arc starting alternately, reverse polarity TIG electric arcs and high-power laser pulses form the composite heat source, and positive polarity TIG electric arcs and low-power laser pulses form the composite heat source. According to the welding method, a self-fluxing brazing welding joint with excellent mechanical properties can be obtained.

Description

technical field [0001] The invention provides a laser-double TIG arc composite self-fluxing brazing method for aluminum alloy and stainless steel, which belongs to the field of welding processing. Background technique [0002] Aluminum alloy is light in weight, has good thermal conductivity and good corrosion resistance, while steel, as the main traditional material in the manufacturing industry, has high strength, good toughness and plasticity, and wide applicability. The aluminum alloy / steel composite structure can not only give full play to the advantages of both, but also reduce the overall weight of the manufactured product under the premise of ensuring performance. Therefore, it has broad application prospects in major national economic fields such as aerospace, mechanical equipment, and rail transportation. However, welding between aluminum and stainless steel has always been a hot and difficult issue in the field of connection. The main difficulties are: first, inte...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a laser-double TIG arc composite self-fluxing brazing method for aluminum alloy and stainless steel, which is carried out in the alternate manner of reverse polarity TIG arc-laser composite heat source and positive polarity TIG arc-laser composite heat source Welding, and the interface is regulated by scanning the laser beam, which solves the problem of uneven interface layer, and can obtain a welded joint with excellent performance and uniform interface layer

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