Corrosion proof fluoride welding agent containing magnesium-aluminium alloy

Abstract

A fluoride solder containing MgAl alloy is prepared from cesium fluoride (38-43 wt.%), AlF3 (52-56) and ZnF2 (2-6) through proportional mixing and grinding. Its soldering temp is lower than 500 deg.C.

Description

technical field [0001] The invention belongs to the field of brazing materials, and in particular relates to a non-corrosion flux used for brazing magnesium-containing aluminum alloys and a preparation method thereof. Background technique [0002] Magnesium-containing aluminum alloys mainly include LF series antirust aluminum, LY series duralumin, LC series super duralumin, LD series wrought aluminum and ZL series cast aluminum alloy, which account for a large proportion of aluminum alloys. Because of their small specific gravity and high thermal and electrical conductivity, they occupy an important position in modern industrial materials. It has been widely used in aerospace, electronics, metallurgy, machinery manufacturing and light industry and other departments. For example, Al-Mg series antirust aluminum is commonly used in aviation kerosene, gasoline and lubricating oil containers and pipes and other weldments, and duralumin is widely used in the production of key com...

AI Technical Summary

Problems solved by technology

However, starting from the brazing temperature, with CsF-AlF 3 The Al-Zn solder that can be used in conjunction with the flux has a high zinc content (greater than 10wt%). The zinc-containing solder is easily burned during the brazing process due to the high vapor pressure of zinc, resulting in the failure of the brazed joint. The chemical composition and performance are reduced, and the higher zinc content in the brazing joint will seriously deteriorate the corrosion resistance and toughness of the brazed joint

In addition, the existing reports at home and abroad do not involve the preparation method of the binary system fluoride molten salt flux

Therefore, the brazing fluxes currently proposed are not suitable for brazing of magnesium-containing aluminum alloys either because the required brazing temperature is relatively high, or because they need to be used in conjunction with Zn-containing brazing filler metals.