TIG brazing process for copper-aluminum dissimilar metal

Abstract

The invention discloses a TIG brazing process for copper-aluminum dissimilar metal. The process includes the steps that the overlapping part of copper and aluminum is subjected to grinding through a fine sandpaper, and cleaning; copper is put on aluminum, the joint is fixed, and a cooling device is arranged at the position of the aluminum; the nozzle of a TIG is arranged at a certain distance fromthe surface of the cupper, and the electric arc of the TIG directly heats the copper; welding wires and the aluminum at a certain angle make laterally contact with the joint of the copper and aluminum, after heating for a suitable time, the welding wires are melted to form a molten pool, then welding wires are fed in at a constant speed, and finally a continuous brazing seam is formed. Through the suitable temperature field formed in the brazing joint portion of copper and aluminum dissimilar metals and the suitable temperature gradient formed between the high and low melting point metals, itis ensured that the welding wires are melted and smoothly filled the joint, and the copper and the aluminum are prevented from melting and dissolving seriously, so that the problem that the performance of the brazing joint reduces due to the formation of a hard and brittle compound through the chemical reaction of the dissimilar metals is solved fundamentally.

Description

technical field [0001] The invention belongs to the technical field of metal welding, and relates to a welding process of dissimilar metals, in particular to a TIG brazing process of copper and aluminum dissimilar metals. Background technique [0002] Copper and aluminum are widely used in power electronics, energy chemical industry, and thermal management systems. The brazing process of copper / aluminum dissimilar metals has always been the focus of research and development in the field of metal welding. However, the widely used copper / aluminum dissimilar metal brazing process is mainly furnace brazing and flame brazing. Not only the production efficiency is low, the manufacturing cost is high, but the metal is also seriously affected by heat, and the copper and aluminum on both sides of the brazing seam occur Dissolving, hard and brittle intermetallic compounds are formed in the brazing seam, which greatly reduces the performance of dissimilar metal brazing joints. In orde...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the above-mentioned problems existing in the prior art, the present invention provides a copper-aluminum dissimilar metal TIG brazing process, by forming an appropriate temperature field at the brazing joint of copper / aluminum dissimilar metals, between high melting point and low melting point metals A suitable temperature gradient is formed between them, which not only ensures the melting of the welding wire and smooth seam filling, but also avoids the melting or severe dissolution of copper and aluminum, thus fundamentally solving the problem of the performance degradation of the brazed joint caused by the combination reaction of dissimilar metals to form hard and brittle compounds The problem

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