One-time welding synchronous two-time reshaping thinning-free friction stir welding tool and welding method.

Abstract

The invention provides a one-time welding synchronous two-time reshaping thinning-free friction stir welding tool and a welding method. The welding tool comprises a welding tool clamping body, an inner side shaft shoulder, a stirring body, a shaft shoulder adjusting bolt, a needle length adjusting bolt, a shaft shoulder fastening bolt and a stirring body fastening bolt, wherein the welding tool clamping body comprises a clamping handle and an outer side shaft shoulder which are integrally formed and coaxially arranged; a first threaded through hole is formed in the axis of the clamping handle;the shaft shoulder adjusting bolt is arranged in the first threaded through hole; and a second threaded through hole is formed in the axis of the shaft shoulder adjusting bolt. According to the one-time welding synchronous two-time reshaping thinning-free friction stir welding tool and the welding method, the pressing-in amount of the inner side shaft shoulder and the pressing-in amount of a stirring needle are adjusted through the two adjusting bolts correspondingly, forming of the interior of a welding seam can be guaranteed in the welding process, the zero pressing-in amount is kept between the outer side shaft shoulder and the surface of a base material to be welded, the inner concave face of the outer side shaft shoulder can contain materials which are extruded by the inner side shaft shoulder and the stirring needle to overflow, the materials are rotationally rolled and reshaped, and the stirring friction welding seam free of flash and thinning is formed.

Description

technical field [0001] The invention belongs to the field of friction stir welding, and in particular relates to a non-thinning friction stir welding tool and a welding method for synchronous secondary reshaping with primary welding. Background technique [0002] Friction Stir Welding (Friction Stir Welding, FSW) is a new type of solid-phase joining method invented by the British Welding Institute (TWI) in 1991. Frictional heat and plastic deformation heat make the workpiece material partially plasticized, and the plasticized material is cooled under the shoulder forging to form a dense joint. Compared with traditional fusion welding, FSW has the advantages of low heat input, small residual stress and deformation, and excellent mechanical properties of joints. No filler material is required in the FSW process, but the shaft shoulder needs to maintain a certain amount of downward pressure to ensure frictional heat generation and weld compaction and strengthening. The plastic...

AI Technical Summary

Problems solved by technology

First of all, the occurrence of weld thinning is often accompanied by weld flash defects, which requires secondary processing, which is time-consuming and labor-intensive

Secondly, the thinning of the weld seam leads to a decrease in the bearing capacity of the joint, especially for thin plate welding, the thinning of the weld seam leads to a more obvious decline in the bearing capacity

Third, the thinning of the weld seam causes stress concentration at the edge of the weld seam, resulting in a decrease in the fatigue resistance of the component

However, the welding tool design of static shoulder friction stir welding is more complicated, the continuous working ability and life are reduced, and the control accuracy of working conditions and indentation is high, which limits its wide application in non-thinning friction stir welding. Applications, especially thick plate welding, are prone to insufficient heat input, resulting in weak connections

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