Magnesium and steel special metal superaudio frequency pulse laser smelting braze-welding wire and welding method

Abstract

The invention provides a magnesium and steel special metal superaudio frequency pulse laser smelting braze-welding wire and a welding method. The welding method comprises the following steps of: forming a beveled edge on a part to be welded of a magnesium alloy and a steel workpiece, and removing oil dirt and an oxidation film from the surface of the workpiece; fixing the magnesium alloy and the steel workpiece on a welding fixture, adjusting the position and the angle of a wire feeding device, automatically feeding the welding wire at a certain angle in front of a laser beam, and protecting a welding seam through argon, wherein the welding wire comprises the following components in percentage by weight: 2 to 10 percent of Al, 0.5 to 5 percent of Zn, 0.1 to 1 percent of Sr, 0.05 to 0.2 percent of B, 0.5 to 2 percent of RE and the balance of Mg; and placing the laser beam on one side of the magnesium alloy workpiece in a slightly deviating way, and heating the welding wire and the magnesium alloy workpiece by using superaudio frequency pulse laser to form a smelting pool, wherein the steel workpiece is kept in a solid state substantially in a welding process and acts with liquid magnesium alloy to form a welding joint. The key and common problem that the improvement of the welding quality of Mg / Fe and Mg / Ti immiscible heterogeneous metal is limited is solved, and the application range of laser smelting braze-welding is expanded.

Description

technical field [0001] The invention relates to a welding material, and the invention also relates to a welding method. Background technique [0002] Magnesium and magnesium alloys, as the lightest engineering structural materials among metals, have the characteristics of high specific strength, high dimensional stability, high damping and shock absorption, and easy recycling. They are known as "green engineering materials in the 21st century". The composite structure formed by magnesium and steel has a series of excellent properties such as light weight, high strength, energy absorption, and good shielding, and has been widely used in the fields of automobiles, aerospace, and electronic communications. For example, in the design of aerospace vehicles, the use of magnesium-steel composite structures can take into account the requirements of overall weight reduction and local load-bearing enhancement. This composite structure is a development trend for key aerospace component...

AI Technical Summary

Problems solved by technology

[0004] 1) The connection of magnesium-steel dissimilar metals is mostly limited to solid phase connection: such as diffusion welding, friction stir welding, resistance spot welding, etc. These methods are easily limited by the shape and size of the workpiece, and the efficiency is low, which is difficult to meet mass production need

[0005] 2) The existing magnesium-steel melting (brazing) welding connection method fails to effectively solve the welding problems of the two: to solve the problems of large difference in melting point, small mutual solubility, and no intermediate reaction phase formation, at present, the middle foil layer is mostly used. Or coating method to solve, but the loss of the middle layer material and the oxidation of the magnesium alloy during the welding process is an essential defect that is difficult to overcome

Fusion welding or brazing methods of practical value have not yet been developed

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