Embedded stirring and rubbing slit welding method

Abstract

The invention discloses an embedded stirring and rubbing slit welding method for dissimilar metals, which is especially suitable for large-area lap connection of aluminum or magnesium or harder metal materials. The embedded stirring and rubbing slit welding method comprises the steps of: firstly, processing one or more dovetail grooves on a second harder base material; secondly, assembling according to a lap connection form, and placing an aluminum plate on the upper sides of the dovetail grooves of the second harder base material; using a needle-free stirring head and installing in an inclining manner; starting the stirring head to rotate and enabling the stirring head to be in contact with the upper surface of the aluminum plate, wherein the pressing depth of the stirring head is limited to about between 0.1mm and 2mm and a welding interface needs not to be penetrated; after rubbing and preheating for several seconds at the starting end, moving the rotating stirring head or operating platform so that the aluminum plate is helically extruded in a groove of a lower plate and the welding or cladding is completed. Compared with the resistance slit welding, the method disclosed by the invention has remarkable energy saving advantage. Compared with the traditional stirring rubbing welding, the method disclosed by the invention has the advantages of no keyhole and no abrasion to needles by the harder base material. The method can be used for welding, and can also be used for preparing a bimetal composite plate.

Description

technical field [0001] The invention belongs to the field of welding, and relates to a seam welding and a method for preparing a composite plate, in particular to an embedded friction stir seam welding method. technical background [0002] The welding of aluminum and dissimilar high-strength metals (such as Fe, Cu, Ti, stainless steel, etc.) is a technical problem that has existed for many years due to their poor metallurgical compatibility (easy to form brittle intermetallic compounds). Especially in industries such as transportation machinery and bimetal composite panels, welding between dissimilar metals is extremely common. For example, in the transportation equipment manufacturing industry represented by automobiles and light rail cars, in order to save fuel and reduce emissions, light-density aluminum is gradually being introduced to replace steel. On the other hand, in the field of Al / Steel bimetal composite plate preparation (commonly used field explosion welding, v...

AI Technical Summary

Problems solved by technology

[0003] In terms of brazing, brazing in traditional furnaces has the following obvious disadvantages: (1) Due to the slow heating / cooling rate, not only the production efficiency is low, but also the intermetallic compound is excessively thickened and the joint is brittle

(2) Protective gas or vacuum environment is required, which increases production cost or equipment investment

In terms of solid-phase welding, although friction stir welding (FSW: frictionstir welding) has been reported to be used in the manufacture of aluminum alloy rims, light rail cars, and aluminum containers, when one of the base materials is a relatively hard steel, due to the steel The direct contact friction with the stirring needle makes the stirring needle extremely worn, resulting in a significant shortening of the service life of the tool and unsustainable welding

[0005] In order to avoid the wear of the needle, although the needleless stirring head can be used, the new contradiction arising from this is that the cancellation of the needle will lead to the loss of the mechanical stirring and mixing effect between the two base metal interfaces.

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