A Friction Stir Welding Method for Suppressing Weld Thinning and Thickening Weld

Abstract

The invention provides a friction stir welding method for restraining welded joint thinning and thickening a welded joint. The friction stir welding method includes the steps that firstly, cleaning isconducted before welding, an oxide film on the surface of a sheet to be welded is removed by mechanical polishing, and then organic solvents or cleaning agents are adopted to wipe the surface of thesheet to be welded to remove sundries; secondly, materials and shapes of a stirring head and a consumptive friction head are selected, the material and the shape of the stirring head are determined according to the properties and the thickness of the sheet to be welded, the consumptive friction head is made of the same material as the sheet to be welded, and the diameter of the consumptive friction head is equal to or larger than that of shaft shoulders of the stirring head; thirdly, positioning is conducted, the relative position of the sheet to be welded is adjusted to make the axis of the stirring head and the axis of the consumptive friction head face the center line of a to-be-welded position of the sheet to be welded, and the consumptive friction head is arranged directly behind thestirring head; and fourthly, welding is carried out. The friction stir welding method eliminates welded joint thinning and achieves welded joint thickening, so that the service life of the welded joint is remarkably prolonged.

Description

technical field [0001] The invention belongs to the field of friction stir welding, and in particular relates to a friction stir welding method for suppressing weld seam thinning and thickening the weld seam. Background technique [0002] As a new solid-phase joining technology, friction stir welding has been widely used in aerospace, high-speed rail and ships. However, due to the inherent characteristics of its technology, the problem of joint thinning is unavoidable. The thinning of friction stir welded joints has adverse effects on joint quality and service performance. The thinning of the joint is generally accompanied by the appearance of flash, and the surface of the weld needs to be polished twice, resulting in an increase in production cost and a decrease in production efficiency; the effective bearing area of ​​the weld is reduced, resulting in a decrease in the bearing capacity of the joint; stress is generated at the edge of the weld Concentration, under fatigue...

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Problems solved by technology

[0003] In view of this, the present invention aims to propose a friction stir welding method that suppresses weld seam thinning and thickens the weld seam, and utilizes the consumable friction head to eliminate weld seam thinning and realize weld seam thickening, thereby significantly improving The service life of the weld seam solves the problems of flashing, effective thickness thinning and stress concentration caused by the thinning of the weld seam in friction stir welding

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