Aluminium matrix composite, brazing filler metal for aluminium alloy and brazing method

Abstract

In order to improve the defect that the interface of a Zn-Al brazing filler metal and an Al matrix has no reaction or the reaction is not uniform (limited to a corrosion section and part crystal boundary), the invention discloses an aluminium matrix composite, a low-melting-point Zn-Al-Mg ternary active brazing filler metal (comprising 3-10% of Al, 2-7% of Mg and the balance of Zn, wherein the corresponding melting range is 337-475 DEG C) and a low-frequency low-amplitude reciprocating friction assistant low-temperature active soft brazing method. The low-temperature active soft brazing method is used as the other auxiliary method under the low-temperature working condition, when the low-frequency low-amplitude friction is applied, and the improvements on the liquid-phase liquidity, the striping effect and the wetting property are more notable. The low-frequency low-amplitude friction assistant low-temperature active soft brazing method comprises the following steps of: presetting brazing filler metal, then pressurizing and heating, canceling the pressure until the temperature is 330 DEG C, sequentially heating until the temperature is 400-550 DEG C, performing heat preservation and leading in the low-frequency low-amplitude friction. According to the method, a soldering flux is not needed, the brazing filler metal prematurity loss is avoided, and no obvious corrosion and / or ceramic grain prejudiced collection is caused; and the brazing filler metal uniformly infiltrate, the diffusion required time is shortened, and protected gas is not essential.

Description

Technical field: [0001] The invention relates to the improvement of Zn-based low-melting-point brazing filler metal formula of aluminum-based composite materials and aluminum alloys and the improvement of the brazing process, and develops a flux-free low-melting-point Zn-Al-Mg series ternary active brazing filler metal formula, and for it Used in conjunction with low frequency low amplitude friction assisted active brazing methods. Background technique: [0002] As we all know, the primary problem to be solved in the brazing of aluminum matrix composite materials and aluminum alloys is how to effectively remove the oxide film on the surface of the aluminum substrate. At present, there are three methods to break the oxide film on the surface of the aluminum alloy or aluminum matrix composite material: (1) chemical methods, such as flux [1], cleaning with chemical reagents before welding [2], adding active elements to the solder [ 3] and other methods; (2) physical methods, s...

AI Technical Summary

Problems solved by technology

[0033] The purpose of the present invention is to improve the low-melting point Zn-Al solder and the Al matrix interface without reaction and there is an interfacial gap, or the reaction is not uniform (only in the corrosion and part of the grain boundary before it reacts with the Al matrix) resulting in the surface of the grain itself. The effect of removing the oxide film is not good, the wettability is still obviously poor in a wide range, and the disadvantages of voids appear on the interface

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