Cesium and rubidium brazing flux containing zinc tetrafluoroborate hydrate

Abstract

The invention discloses cesium and rubidium brazing flux containing zinc tetrafluoroborate hydrate. The cesium and rubidium brazing flux comprises, by mass percentage, 0.001%-0.01% of rubidium fluoride, 10.0%-50.0% of cesium fluoride, 0.01%-5.0% of aluminum oxide, 0.01%-5.0% of potassium fluoride, 0.001%-0.25% of zinc tetrafluoroborate hydrate and the balance aluminum fluoride. According to the cesium and rubidium brazing flux containing zinc tetrafluoroborate hydrate, zinc tetrafluoroborate hydrate is added, the usage amount of rubidium fluoride is reduced greatly, brazing of the same material of aluminum-aluminum, dissimilar materials of aluminum-cooper, dissimilar materials of aluminum-steel and an alloy material of aluminum-aluminum can be achieved, the material cost is reduced remarkably, and the brazing flux has excellent capacity of removing FeO, Fe2O3, NiO, Cr2O3 and other oxide on the surface of aluminum alloy or steel; and the brazing flux on the base metal has excellent wetting performance, spreading performance and penetrating performance, the brazing seam strength can reach 125 MPa to 145 MPa, and the requirements for low lost, high reliability and environmental-friendly manufacturing of the industries of air conditioners, refrigerator complete machines, refrigeration accessories, rail transit and energy can be met.

Description

technical field [0001] The invention belongs to the technical field of brazing materials of non-metallic materials, and in particular relates to a cesium-rubidium brazing flux containing zinc fluorine borate which can braze aluminum-steel, aluminum-copper and aluminum-aluminum. Background technique [0002] With the rapid development of aerospace, automobile, rail transit, energy industry and other industries, in addition to the extensive use of aluminum-aluminum structures, there are more and more applications for composite structures of copper and aluminum alloys, steel and aluminum alloys. So far, there are still many problems to be solved urgently in the "connection" of aluminum-steel and aluminum-copper bimetallic composite materials. Studies have shown that the oxides on the surface of aluminum alloys are mainly Al 2 o 3 , MgO, MnO, CuO, SiO 2 etc., the oxides on the steel surface are mainly FeO, Fe 2 o 3 , NiO, Cr 2 o 3 etc., the oxides on the surface of copper...

AI Technical Summary

Problems solved by technology

Studies have shown that the oxides on the surface of aluminum alloys are mainly Al 2 o 3 , MgO, MnO, CuO, SiO 2 etc., the oxides on the steel surface are mainly FeO, Fe 2 o 3 , NiO, Cr 2 o 3 etc., the oxides on the surface of copper alloy are mainly CuO, Cu 2 O, ZnO, etc. However, it is difficult to remove oxides on the surface of aluminum alloy, steel, and copper alloy at the same time by using a flux

In recent years, CsAlF 4 , KCsAlF 4 and CsF-RbF-AlF 3 Flux can remove the oxides on the surface of aluminum alloy and copper alloy well simultaneously, which solves the brazing problem of aluminum-copper dissimilar materials, but the effect of simultaneously removing the oxides on the surface of aluminum alloy and steel (or stainless steel) is still not enough ideal

[0003] Chinese patent CN201310445105.3 discloses a new type of flux used for brazing stainless steel and aluminum, and its composition includes potassium tetrafluoroaluminate + potassium hexafluoroaluminate (KAlF 4 +K 3 AlF 6 ) eutectic, zinc fluoride (ZnF 2 ), copper fluoride (CuF 2 ), tin fluoride (SnF 4 ), although by adding zinc fluoride, copper fluoride and tin fluoride to KAlF 4 +K 3 AlF 6 Modified so as to be able to braze stainless steel and aluminum, but does not give the solder that the flux "matches" and the mechanical properties of the brazed joint (such as tensile strength or shear strength), and cannot be brazed Aluminum-copper dissimilar materials

where GaF 3 With LiF, BF 3 The molar ratio between GaF 3 :LiF:BF 3 =2︰1︰1, however, its formula is too complex, and quality control during production is very difficult

[0005] Chinese patent CN201410752345.2 discloses a cesium-rubidium brazing flux containing gallium oxide, which is characterized in that the ratio of moles to one mole is: 0.12 moles to 0.5 moles of rubidium fluoride (RbF), 0.12 moles to 0.5 moles cesium fluoride (CsF), 0.001 mole to 0.2 mole alumina (Al 2 o 3 ), 0.001 to 0.02 moles of potassium fluoride (KF), 0.0001 to 0.02 moles of gallium oxide (Ga 2 o 3 ), 0.159 moles to 0.479 aluminum fluoride (AlF 3 ), although the invention can simultaneously meet the brazing requirements of "aluminum-copper", "aluminum-steel" and "aluminum-aluminum" and has high activity, but its content of rubidium fluoride (RbF) is as high as 0.12 mole to 0.5 mole , expensive, unable to meet the fiercely competitive manufacturing industry's needs for "high quality and low price" consumable materials

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