Method for filling welding key hole by utilizing friction stir

Abstract

The invention discloses a method for filling a welding key hole by utilizing friction stir. The method comprises the following steps that (1) a stirring head is obliquely inserted into a machining allowance layer relative to a welding surface normal of a workpiece; (2) the end part of the stirring head located in the machining allowance layer is pushed to a key hole position in a machining allowance layer; (3) the stirring head is turned back, and the axis of the stirring head coincides with the center of the key hole; and (4) the stirring head is lifted, and the key hole filling is finished.According to the filling method, the characteristic that the friction heat can soften the workpiece material when the stirring head rotates in the workpiece is utilized, the softening machining allowance material on the surface of the workpiece is migrated to the key hole through the motion of rotating the stirring head, and the softened material fills the key hole through the combined motion of the rotating head.

Description

technical field [0001] The invention relates to a method for filling a keyhole, in particular to a method for filling a welding keyhole by using friction stir, and belongs to the technical field of friction stir welding. Background technique [0002] The so-called friction stir welding refers to the use of heat generated by the friction between the high-speed rotating welding tool and the workpiece to locally plasticize the welded material. When the welding tool moves forward along the welding interface, the rotational friction of the plasticized material in the welding tool Under the action, it flows from the front of the welding tool to the rear, and forms a dense solid-phase weld under the extrusion of the welding tool. Specifically, the welding process of friction stir welding is that a stirring needle (threaded cylinder or other shape) penetrates into the joint of the workpiece, and through the high-speed rotation of the stirring head, it rubs against the workpiece mate...

AI Technical Summary

Problems solved by technology

[0006] 1) During closed-loop weld welding, the stirring needle will continue to move forward at the welded seam position after the welding is completed. During the forward process, the stirring needle will be slowly extracted, and the welded seam will be welded twice. Increased risk of defects in welds;

[0007] 2) The process of slowly extracting the stirring needle must be very slow, and at the same time, the advancing speed of the stirring head and the stirring speed must be matched very accurately, otherwise tunnel holes will be formed in the weld area, and the process is very difficult

[0008] 3) Since the stirring pin is extracted slowly, it is required to take a long welding distance and take a long time when extracting the stirring pin

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