Method for eliminating keyhole-free friction stir spot welding ring groove

Abstract

The invention provides a method for eliminating a keyhole-free friction stir spot welding ring groove. According to the method, through zero point setting before welding, the length of the part, stretching out of a datum plane, of a stirring pin is 10% of the thickness of a to-be-welded base material, the length of the part, stretching out of the datum plane, of a stirring sleeve is 80% of the stretching length of the stirring pin, and at this moment, the positions of the stirring pin and the stirring sleeve are set as zero points, that is, the zero points are determined by a numerical controlsystem; and before a stirring tool moves downwards, the stirring pin and the stirring sleeve are drawn back at the same time. After the stirring pin and the stirring sleeve are welded and return to the original point, the stirring pin continues to move downwards; and when the quantity that the stirring pin continues to move downwards is 20% of the thickness of the base material, the stirring pinis kept at the position to rotate for 1 s to 2 s, aluminum metal in a molten state is fully backfilled to the position around the welding point, the stirring pin and the stirring sleeve return to theoriginal point and rotate for 1 s to 5 s, the periphery of the welding point is fully filled with the aluminum metal in the molten state, and the aim of eliminating the welding defect ring groove is achieved. The method is used for welding of aluminum plates of 1 mm, 2 mm, 3 mm, 4 mm and 5 mm, and the welding ring groove defect is eliminated.

Description

technical field [0001] The invention relates to the field of welding technology, in particular to a method for eliminating grooves in keyhole-less friction stir spot welding rings. Background technique [0002] "Linear" friction stir welding technology was invented by the British Welding Institute (TWI) in 1991. Friction stir spot welding technology (referred to as FSSW technology) is a new welding method developed on the basis of "linear" friction stir welding. . Keyhole friction stir spot welding is a kind of welding in a solid state. When welding, the temperature is below the melting point of the material, so that after the welding is completed, the properties of the metal do not change, and it is a repeatable and safe welding method. high welding method. [0003] In this welding method, the base metal is lost due to the adhesion of the stirring tool to the base metal, which is very prone to welding defects: ring grooves. The surface of the ring groove solder joint is ...

AI Technical Summary

Problems solved by technology

[0003] This welding method is prone to welding defects: ring groove

The reason for the ring groove is that the radial direction of the outer circle of the stirring sleeve and the radial direction of the inner hole of the compression sleeve are severely worn, and the gap between the stirring sleeve and the compression sleeve gradually becomes larger, resulting in the part of molten aluminum entering into the welding process. In the gap, metal loss occurs after welding, and ring groove defects seriously affect the mechanical properties of solder joints

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