Solvay Fluor Und Derivate Gmbh

Solvay Pharmaceuticals, Gmbh

Solvay Fluor and Derivative Gmbh

Solvay Fluor Gmbh

Joachim Frehse

Ulrich Seseke-Koyro

Andreas Becker

Fluxing agents comprising potassium fluorostannate and/or cesium fluorostannate which can be used for brazing or soldering components of aluminum or of an aluminum alloy, even by solderless brazing or soldering. Conventional fluxing agents or other fluorometallates, such as alkali metal fluorozincates and/or alkali metal fluorosilicates, can also be added to the fluorostannate-containing fluxing agent. The fluxing agents of the invention can be applied by either dry or wet fluxing methods.

Fluorostannate-containing brazing or soldering fluxes and use thereof in brazing or soldering aluminum or aluminum alloys

Novel methods for producing alkali metal fluorozincates, especially potassium fluorozincate. Products having defined particle size ranges are obtained depending on the sequence of introduction of the reactants alkali metal hydroxide, zinc oxide and hydrogen fluoride. The resulting alkali metal fluorozincates are particularly suitable for use as a fluxing agent or fluxing agent additive during brazing of aluminum or aluminum alloys and can be applied by wet or dry fluxing methods depending on the particle size of the alkali metal fluorozincate particles.

Alkali metal fluorozincate and method for producing it

Components composed of aluminum or an aluminum alloy with a coating comprising an aluminum-silicon alloy deposited thereon by applying an alkali metal fluorosilicate and heating the resulting treated material. The alloy layer is effectively protected against re-oxidation by a non-corrosive, alkali metal fluoroaluminate layer (e.g. a potassium fluoroaluminate layer) which forms simultaneously.

Components coated with an aluminum-silicon alloy

Components made of aluminum and aluminum alloys can be brazed at temperatures of up to 600&deg; C. using a fluxing agent composed of alkali fluorozincate or alkali fluoride/zinc fluoride mixtures. Other fluxing agents, for example those composed of potassium fluoroaluminate can be used in addition. Alkali fluorozincate fluxing agents, especially potassium and cesium fluorozincate fluxing agents, act not only as a fluxing agent but also improve the surface quality since zinc and alkali fluoroaluminates are deposited on the surface of the components. The invention also relates to new fluxing agents containing alkali metal fluorozincates.

Growing community of inventors

Hannover, Germany

Joachim Frehse