Heat source auxiliary compound double-axis needleless dynamic friction stir welding method

Abstract

The invention discloses a heat source auxiliary compound double-axis needleless dynamic friction stir welding method. Positive and negative electrode dynamic clamping heads and a guide pretightening wheel are adopted to finish clamping of workpieces to be welded; a direct-current switch power supply is used for providing high-density current into the workpieces to be welded; metals in joints of the workpieces to be welded are preheated; stirring heads rotating at high speed are pressed in two sides of the joints; positive pressure is applied to the metals in the joints through shaft shoulders, so that the metal materials in the joints are softened; the stirring heads rotating at high speed enable the metal structures in the joints to achieve a plastified state under the friction stirring effect; meanwhile, a ultrasonic exciter is adopted to finely forge the plastified metals; the workpieces to be welded are forwards fed along with a welding worktable in the directions of the joints; and the plastified metals are continuously filled in a cavity formed after movement of the stirring head under the stirring and extruding effects of the stirring heads, and are gradually cooled to condense as final welding lines. The method relieves the wear of the stirring heads, increases the welding thickness, accelerates the welding speed, and reduces the welding defects.

Description

technical field [0001] The invention belongs to the technical field of friction stir welding and forming, and in particular relates to a heat source-assisted composite biaxial needleless dynamic friction stir welding method. Background technique [0002] Friction stir welding (FSW) is a solid phase welding technology, originally used for the connection of low melting point metals (such as aluminum alloys and magnesium alloys, etc.), because there is no melting of materials in the FSW process, so this technology can avoid traditional fusion welding Common problems such as cracks, pores and deformation, and have low requirements for operation and equipment. Although the research on friction stir welding technology has been more and more in-depth, but there are still deficiencies in this technology. [0003] Friction stir welding mainly stirs the workpiece through the stirring head, and relies on frictional heat to heat the metal around the joint of the workpiece to a plastic ...

AI Technical Summary

Problems solved by technology

Therefore, in the special high temperature environment of friction stir welding, when welding metal materials with high melting point, the wear of the stirring head is serious and the equipment is generally heavy and complicated.

In addition, when welding materials with high melting point and large thickness, the welding speed is often low

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