Agitating friction spot welding device and method for dissimilar metal

Abstract

The invention provides an agitating friction spot welding device for dissimilar metal. The device comprises an agitating sleeve, an agitating needle arranged in the agitating sleeve, a clamping sleeve clamped outside the agitating sleeve, and a welding cushion block; a welding workpiece is arranged between the clamping sleeve and the welding cushion pad; an annular electric brush is arranged at the top of the welding cushion block; a T-shaped through hole is formed in the center of the welding cushion block; a conductive rod is arranged in the welding cushion block; the conductive rod is flush with the upper surface of the welding cushion block; and the annular electric brush and the conductive rod are respectively connected with an anode and a cathode of a controllable direct current power supply through a lead. The invention further provides an agitating friction spot welding method for dissimilar metal. The method comprises the following steps of plastically softening metal material, respectively connecting the annular electric brush and the conductive rod with a direct current power supply which has the reversed polarity, so as to conduct a welding loop, and then finishing the welding by adopting a spot welding process. According to the device and the method provided by the invention, as certain welding current is applied to the welding material which is high in lower layer strength during the agitating friction spot welding process of the dissimilar metal, the material is more easily and plastically distorted, the welding pressure is reduced and the welding quality is improved.

Description

technical field [0001] The invention relates to a device for friction stir spot welding of dissimilar metals and a method for performing stir spot welding using the device. Background technique [0002] With the increasingly severe global resource supply and environmental protection, automobile lightweight has attracted more and more people's attention, and has become the main direction of the development of today's automobile industry. The use of light alloys such as aluminum and magnesium and high-strength steel materials is an important measure to achieve lightweight. However, the physical properties of light alloys such as aluminum and magnesium and high-strength steel materials are quite different, and hard and brittle intermetallic compounds are easily formed during welding. Therefore, the joint welding quality is poor when using traditional resistance spot welding methods. [0003] Friction stir spot welding technology is a new type of solid-phase joining technology,...

AI Technical Summary

Problems solved by technology

[0004] However, in the process of friction stir spot welding, when the lower plate is made of high-strength high-strength steel, due to the high resistance to plastic deformation of the welding material, a large welding force is required, so the strength, hardness and welding system of the stirring head are raised. higher requirement

Moreover, the difficulty of plastic flow of materials leads to poor welding quality and poor welding performance of spot welded joints

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