A friction stir welding device and method for realizing weld thickening

Abstract

A friction stir welding device capable of realizing weld thickening, the device comprising a zero-tilt-angle welding module (3), a constant pressure control module (1) and a stirring tool module (2). By means of the zero-tilt-angle welding module (3), a center line of a stirring tool always remains parallel to the normal direction of a surface of a workpiece to be welded during welding. The constant pressure control module (1) keeps an axial pressure of the stirring tool on the workpiece constant during welding. The stirring tool module (2) comprises a shaft shoulder (5), a stirring pin (6) and a clamping end (4). A method for welding using the friction stir welding device is further provided. By means of zero-tilt-angle welding, the requirements for a welding apparatus during two-dimensional and three-dimensional welding of welds are reduced, thereby omitting a tilt angle adjustment mechanism and expanding the application range of friction stir welding. Material addition can be implemented in a weld area without filling with an external material, thereby solving the problem of weld thinning and improving the fatigue performance of the weld area.

Description

technical field [0001] The invention belongs to the field of friction stir welding, and in particular relates to a friction stir welding device and method for thickening the weld seam, which can realize material increase in the weld seam region without external material filling. Background technique [0002] As a new solid-phase joining technology, friction stir welding is widely used in aerospace, automobile, ship and other fields. In traditional friction stir welding, the shoulder needs to apply a certain amount of indentation to the surface of the welded workpiece to ensure that the thermoplastic material can obtain sufficient upsetting force to form a high-quality joint. The existence of the indentation will cause the thinning of the weld seam and produce flash on both sides of the weld seam. Weld thinning reduces the mechanical properties of welded joints, especially under fatigue loading, which can severely reduce the fatigue properties of materials in the weld zone. ...

AI Technical Summary

Problems solved by technology

However, this method results in a large amount of material removal, waste of workpiece materials, and low production efficiency.

At the same time, the existence of flashing increases the investment in the post-welding deflashing process and related equipment, resulting in an increase in production costs

The application number is 201410138224.9, and the Chinese patent titled "A Welding Tool and Welding Method for Realizing Zero Thinning of Friction Stir Welding Seam" discloses the process of zero thinning of weld seam. The control mode is always zero, and the shoulder adopts a concave structure, the material added by the weld is easily removed by the shoulder, and the effect of weld thickening is limited

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