Degussa Aktiengesellschaft

Other

Harald Krappitz

Wolfgang Weise

Willi Malikowski

Dieter Kaufmann

Alexander Voelcker

Manfred Koschlig

Joerg Beuers

Wolfgang Weber

J&uuml;rgen Koch

Klaus Schmitt

Klaus L&ouml;nne

Cadmium-free hard solders having working temperatures of less than 630&deg; C., which are easily workable and yield ductile soldered joints, are composed of 30 to 60% by weight of silver, 10 to 36% by weight of copper, 15 to 32% by weight of zinc, 0.5 to 7% by weight of gallium, 0.5 to 7% by weight of tin and 0 to 5% by weight of indium.

Cadmium-free silver alloy as low-melting brazing filler material

A process for producing, on a metallic substrate, a geometric metal structure having a precise contour, including the steps of: solder coating a solder paste onto the substrate by screen printing to create the geometric metal structure, the solder paste comprising an organic binder system, and 80 to 95 weight % of a mixture of a nickel-based solder and a pulverulent alloy of nickel with at least one member selected from the group consisting of chromium, molybdenum, tungsten, manganese and iron, provided as a higher-melting metallic filler, wherein a weight ratio of solder to filler is 2-6:1, an average grain size of the solder is between 10 and 50 &mgr;m, and a grain size ratio of solder to filler, relative to the average grain size is from 0.5-2.5:1; drying the structure; decomposing the organic binder system present in the solder paste, without leaving a reside, by a heat treatment; and raising the temperature until the resulting solder material liquifies.

Soldering paste for producing geometrical metal structures with precise contours

Cadmium-free brazing solders with working temperatures under 630.degree. C. containing 45 to 80 wt. % silver, 14 to 25 wt. % copper 10 to 25 wt. % gallium, 1 to 7 wt. % zinc and 0 to 5 wt. % indium and/or tin. The alloys have good cold workability and ductility.

Cadmium-free silver alloy brazing solder, method of using said solder,

When hard-substance parts are soldered onto steel bases, thermal stresses are produced between the hard substance and the steel. These stresses can be reduced by means of using a multilayer solder in which the middle layer consists of a precipitation-hardenable copper alloy or nickel alloy provided on both sides with a layer of a hard-solder alloy whose working temperature is at least 50.degree. C. below the melting point of the precipitation-hardenable copper alloy or nickel alloy. A tempering treatment at 250.degree. to 550.degree. C. is carried out after the soldering in order to achieve a precipitation hardening of the middle layer.

Method for soldering hard substances onto steels

Parts subject to wear having coatings made of hard substances formed by subdividing the protective layer into segmented joint faces and wherein the joint faces interlace to form seams that are as close as possible to each other.

Work pieces having a wear resistant coating produced by brazing and

Cadmium-free brazing solders with working temperatures under 630.degree. C. containing 45 to 80 wt. % silver, 5 to 13 wt. % copper, 10 to 25 wt. % gallium, 8 to 20 wt. % zinc, and 0 to 5 wt. % indium and/or tin.

Growing community of inventors

Hanau, Germany

Harald Krappitz