Aluminum-steel mixing, friction and connection method

Abstract

The invention discloses an aluminum-steel mixing, friction and connection method, comprising the following steps: forming a saw-toothed slot in a plate thickness direction before the connection of a steel plate (5), wherein the tooth depth delta is equal to 1.5-2mm, a first inclined angle alpha of the saw-toothed slot is equal to 25-30 degrees, a second inclined angle beta of the saw-toothed slot is equal to 45-50 degrees, the tooth pitch D is equal to 3-4mm, the length of the steel plate (5) is L, L / D is the number of arranged saw teeth, the steel plate (5) and an aluminum plate (4) are spliced together along an end line (PP') of the aluminum plate (4), steel is arranged at an advancing side of a mixing head, while an aluminum material is arranged at a retreating side of the mixing head, and the end line (PP') is vertical to a plane where an axial line (OO') of a mixing needle (1) is and a plane where the aluminum plate (4) and the steel plate (5) are; the mixing needle (1) is connected in a way of being closer to the aluminum side but sticking close to the top of the saw teeth of the steel side, under the action of an axial upsetting force and the mixing of the mixing needle (1), the aluminum material in a plastic state is enabled to fill the preformed saw-toothed slot, while the steel in the plastic state is transferred into an aluminum substrate, so as to realize the effective connection of the aluminum and the steel.

Description

technical field [0001] The invention relates to a solid-phase connection technology in the field of welding technology, in particular to a solid-phase connection technology for butt jointing of aluminum and steel dissimilar materials. Background technique [0002] In the field of industrial manufacturing, dissimilar metal composite structures have been more and more widely used due to the integration of the respective advantages of the two materials, especially the composite structures of aluminum and aluminum alloy and steel. Aluminum (aluminum and aluminum alloy) has the advantages of light weight, high thermal conductivity, and high electrical conductivity, while steel has the advantages of high strength and good plasticity. Therefore, the composite structure composed of aluminum and steel can effectively reduce the weight of the structure and improve the durability of the material. Strength, corrosion resistance and impact resistance. For example, in the automotive fiel...

AI Technical Summary

Problems solved by technology

[0005] The first is the wear problem of the connecting tool: since the connecting tool is generally made of tool steel, if the connecting tool is directly connected to the steel by friction stir connection, the connecting tool will wear out quickly, and due to the severe friction between the connecting tool and the steel, it will Local high temperature will be generated, resulting in the melting of nearby aluminum materials, and the metallurgical reaction with steel to form brittle intermetallic compounds. The connecting tool directly stirs and rubs with the steel to accelerate the wear of the connecting tool

[0006] The second is the problem of connection quality: since the connection quality of aluminum and steel mainly depends on the connection strength between the two interfaces, in order to ensure the connection strength between them, the effectiveness and moderation of the interface reaction must be ensured

[0007] The third is the mass transfer problem of the interface material: the frictional heat brought by the effective flow of the material will provide sufficient temperature for the interface reaction

[0008] The existence of the above problems makes the connection of aluminum and steel by friction stir welding special. It is necessary to adopt a new connection process and connection tool to ensure the high-quality and stable connection of this dissimilar metal material.

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