Degussa Aktiengesellschaft

Degussa - Huls Ag

Leander Staab

J&uuml;rgen Koch

Karl-Anton Starz

Sandra Wittpahl

Wolfgang Kohlweiler

Jurgen Koch

A soldering paste for hard-soldering and coating working parts made of aluminum or aluminum alloys, which contains 25 to 35 percent in weight of a water-miscible organic binding agent on the basis of aliphatic glycols, 25 to 45 percent in weight of an aluminum hard-soldering powder, 25 to 45 percent in weight of an aluminum fluxing agent and, as an additive to influence the rheological properties, 0.01 to 0.2 percent by weight with respect to the total amount of one or several fatty acids with 10 to 20 C atoms and/or their ammonium salts.

Soldering paste for hard-soldering and coating aluminum and aluminum alloys

The invention relates t a flux-free brazing paste for the brazing of copper and copper alloys. The paste includes a binder consisting of a mixture of polyisobutene with a relative molar mass from 50,000 to 500,000 and paraffin within a melting-range from 40 to 90&deg; C.

Flux-free brazing paste

Relatively resilient flux encasings for solder preforms are obtained when a mixture of 5 to 30 wt. % potassium silicate having a molar ratio of K.sub.2 O:SiO.sub.2 ranging from 1:2.5 to 1:4.5, 0.5 to 10 wt. % concentrated phosphoric acid, 0.1 to 5 wt. % boric acid and 0 to 10 wt. % finely divided silicon dioxide, with the remainder water, is used as the binder.

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Mömbris, Germany

Leander Staab