A Method for Repairing Volume Defects of Metal Components by Friction Stir Welding

Abstract

The invention provides a method for repairing a metal component volumetric defect through stirring friction welding. The bottom surface of a stirring needle of each stirring head is provided with a six-spiral-line groove; each stationary shaft shoulder is composed of four separable shaft shoulder split bodies in a combined mode; the four shaft shoulder split bodies are provided with ultrasonic vibration devices used cooperatively with the four shaft shoulder split bodies correspondingly; and ultrasonic amplitude variation rods are connected with the upper surfaces of the shaft shoulder split bodies. A continuous filling welding method is adopted; the stirring heads required by all stages of filling welding and the stationary shaft shoulders matched with the stirring heads are selected at first; filling pieces of which the dimensions correspond to the diameters of the stirring needles of all the stages of stirring heads and the material is the same as that of a metal component are manufactured; and filling welding is conducted step by step with the assistance of ultrasonic vibration, and after the last stage of filling welding, the stirring heads continue rotating for 1-100 s, and ultrasonic vibration is kept for 200 s. The method for repairing the metal component volumetric defect through stirring friction welding has the beneficial effects that the repair area grain size is refined; the metallurgical bonding and mechanical properties are good; the strength is high; the thickness is not reduced; material overflow is avoided; the stress concentration phenomenon is few; repairing is not limited by the defect depth; and the application range is wide.

Description

technical field [0001] The invention relates to metal welding, in particular to a method for repairing volume defects of metal components by friction stir welding. Background technique [0002] As a new solid-phase welding method, friction stir welding has the advantages of low welding temperature, small deformation and residual stress, and high-quality welded joints. It has been widely used in aerospace, high-speed rail, and ships. During the welding process, a friction stir welding tool consisting of a specially designed shoulder and a stirring head penetrates into the metal component, and friction with the metal component generates frictional heat, which makes the material flow and realizes the connection of the metal component to be welded. [0003] During the friction stir welding process, due to the existence of the stirring pin, a keyhole defect will appear at the end of the welded joint, which will cause weak connection and stress concentration effect, greatly reduce...

AI Technical Summary

Problems solved by technology

[0012] In order to solve the problems existing in the repair of keyhole defects in the existing friction stir welding, the present invention provides a method that can refine the grain size of the repair area, have good metallurgical bonding and mechanical properties, high strength, no thickness reduction, no material overflow, A method for repairing volume defects of metal components with friction stir welding with less stress concentration, repair not limited by defect depth, and wide application range

Images