A method for realizing heterogeneous welding of titanium alloy and aluminum alloy

Abstract

A method for realizing dissimilar welding of titanium alloy and aluminum alloy belongs to the field of solid-phase connection of dissimilar metals. In order to realize the heterogeneous welding of titanium alloy and aluminum alloy and avoid the generation of Ti / Al brittle phase in the welding zone, the invention uses tin as the welding transition metal, and obtains high-quality friction welding seam through friction stir welding, and realizes the realization of titanium alloy and aluminum alloy. Dissimilar welding of aluminum alloys. The invention uses Sn as the intermediate phase, and realizes the heterogeneous welding of the high melting point titanium alloy and the low melting point aluminum alloy through friction stir welding, which not only effectively prevents the formation of brittle phases such as Ti / Al during the welding process, but also prevents the welding temperature from being too high. The resulting large amount of burning loss of the aluminum alloy improves the strength of the welded joint, and at the same time makes the welded joint firm, effectively improving the quality and performance of the welded joint. It has the advantages of simplicity and convenience, high welding efficiency, excellent quality and performance of the obtained welded joint, and greatly reducing labor and processing costs.

Description

technical field [0001] The invention belongs to the field of solid-phase connection of dissimilar metals, and provides a method for realizing heterogeneous welding of titanium alloy and aluminum alloy. Background technique [0002] Friction stir welding mainly uses the friction between the stirring head and the workpiece to generate heat, so that the pre-welded part is in a thermoplastic state, and then the stirring head moves forward while rotating, and the welding material flows plastically from the front end to the rear under the pressure of the stirring head, and finally pressure welded A whole. Since friction stir welding is a solid-state welding, compared with other fusion welding methods, the welding temperature is lower, the grain growth is not obvious, and there are basically no defects such as pores, cracks, and alloy element burning. At present, friction stir welding technology is widely used in aviation, aerospace, nuclear energy, vehicles and other fields, main...

AI Technical Summary

Problems solved by technology

[0004] For the heterogeneous welding of titanium alloy and aluminum alloy, there will be the following difficulties in the welding process: 1. Titanium and aluminum are active metals, which will react with air during the welding process to form inclusions, resulting in deterioration of weld performance; 2. Titanium There is a huge difference from the melting point of aluminum. Under the same welding heating conditions, when the temperature reaches the melting point of titanium, it will cause a large amount of burning and loss of elements in the aluminum alloy; 3. Titanium and aluminum will form a Ti / Al brittle phase at the weld, As a result, the mechanical properties of the weld are severely reduced, and the elongation is greatly reduced. Under the action of welding stress, it is easy to cause cracks in the weld, which leads to the deterioration of the plasticity and high temperature performance of the joint, thereby affecting the service life of the weldment.

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