A Stirring Head for Eliminating Friction Stir Welding Keyholes

Abstract

The invention relates to a stirring head for eliminating the friction stir welding keyhole, which comprises a clamping device, a spring, a conical reflective surface, a connecting piece, a positioning key, a shaft shoulder, a thimble, a stirring needle and a laser range finder. The invention can eliminate the keyhole in the traditional friction stir welding, while maintaining the high quality, high efficiency, low cost, low deformation, easy automation, no need for shielding gas, low energy consumption, no pollution to the environment and many other advantages of the friction stir welding technology itself. The advantage is that it is a new "green" repair welding method worthy of the name, which is of great significance to improve the welding quality of friction stir welding.

Description

technical field [0001] The invention belongs to the field of metal material processing, and in particular relates to a stirring head for eliminating friction stir welding keyholes. Background technique [0002] Friction Stir Welding (Friction Stir Welding, FSW) is a new solid-phase joining technology proposed by The Welding Institute (TWI) in 1991. Compared with traditional fusion welding, friction stir welding has the following advantages: (1 ) The joint quality is high, and defects such as pores and cracks are not easy to occur; (2) The welding cost is low, no filler material and shielding gas are required, and thick welded parts do not need to process grooves; (3) The welding process is safe, free from pollution, spatter, smoke, dust, Noise, etc., and there is no serious electromagnetic interference and harmful substances, it is an environmentally friendly connection method; (4) The weldment is rigidly fixed during the welding process, and the heating temperature is low d...

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Problems solved by technology

[0004] When performing friction stir welding on certain structures, the welding starting plate and the lead-out plate can be set at the position of welding start and welding, so that the keyhole does not stay on the workpiece; or lead out the friction stir welding at the opening of the product part Welding the keyhole, such as drawing the keyhole at the mouth frame on the cabin body, and then processing and removing it; but on the one hand, this method causes a lot of waste of materials, and on the other hand, it is not suitable for the circular seam welding of the rotary structure. The friction stir welding of thin plates can be welded with a needleless stirring head. During the welding process, only relying on the interaction between the rotating shoulder and the metal on the surface of the weldment generates a large amount of frictional heat, which promotes the flow and mixing of the internal metal, thereby forming Solid-phase connection joints, this method has high requirements on the cross-sectional shape of the shaft shoulder due to the absence of the stirring effect of the stirring pin. Although no keyholes are produced during the friction stir welding process, its applicable structure has great limitations. The friction and stirring effect between the stirring head and the base metal are weakened, and the mechanical properties of the joint are greatly reduced. In addition, the stirring needle retraction technology is used to eliminate the keyhole during friction stir welding, but the stirring needle retraction equipment is relatively complicated, and it is difficult for stirring Needle performance requirements are high, not suitable for high-speed friction stir welding

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