RU2317881C1 - Solder for palladium and its alloys - Google Patents

Abstract

FIELD: metallurgy; soldering alloys.

SUBSTANCE: invention relates to metallurgy of solders and brazers on base of precious metals, particularly, palladium, which are used in manufacture on jewelry articles made of palladium alloys, fineness 850. proposed solder contains components of following ratio, mass %: palladium 84.5-85.5; germanium 3.0-7.0; gallium 1.0-6.0, the remainder being copper. Summary content of germanium and gallium does not exceed 10 mass %. Solder features sufficiently ready fusibility and wettability of parts of article to be soldered and provides coincidence of fineness and color identity of base and soldered joint in jewelry article.

EFFECT: improved quality of ready article.

1 ex, 1 tbl

Description

The invention relates to the metallurgy of solder alloys based on noble metals, in particular palladium, used for soldering palladium and its alloys, and is intended for use in the manufacture of jewelry from alloys of palladium, mainly 850 samples.

Solder alloys based on precious metals used in jewelry production, in addition to the usual requirements for solders, such as relative fusibility, good wettability of the base metal, fluidity, ductility and strength of the brazed joint, must also meet a number of additional requirements: their fineness and color should be identical with the details of the soldered products.

The closest in technical essence to the claimed is a solder for soldering palladium and its alloys, containing, wt.%:

palladium - 50.0-50.5;

silver - 1.0-45.0;

copper - 1.0-43.0;

silicon - 0.1-6.0;

zinc - up to 3.0,

moreover, the total content of silver and copper does not exceed 49 wt.%. [RF patent No. 2176180, declared. 09/07/2000, reg. Application No. 2000123318/02, publ. November 27, 2001 Authors: Timofeev NI, Ermakov A.V., Grokhovskaya L.G. and etc.]. This solder is adopted as a prototype.

Common to the known and claimed solders is the presence in their composition of palladium, copper and other alloying additives.

Known solder is designed for brazing palladium and jewelry from standard alloys of palladium 500 samples, which ensures in this case the preservation of fineness of the base and solder joints in the finished jewelry. However, this solder cannot be used for brazing standard jewelry alloys of palladium 850 samples, in particular alloys ПдСрН 850-130, ПДМ 850 and alloy ПДКМ 850-10, since it does not ensure preservation of fineness of the base and solder joint in the finished product.

The invention is aimed at obtaining a technical result, which consists in developing a composition of solder for brazing palladium and jewelry from its alloys of 850 samples, in particular alloy PDKM 850-10, which ensures preservation of fineness and color identity of the base and solder joint in the finished jewelry product, satisfactory fusibility of solder and good wettability with solder soldered parts of the product.

The technical result is achieved by the fact that in the inventive solder containing palladium, copper and alloying additives, the palladium content is 84.5-85.5%, and germanium and gallium are used as other alloying additives in the following ratio of components, wt.%:

palladium - 84.5-85.5;

Germany - 3.0-7.0;

gallium - 1.0-6.0;

copper - the rest

moreover, the total content of germanium and gallium does not exceed 10 wt.%.

The content of palladium in the inventive solder is determined including GOST requirement for solders for soldering standard jewelry alloys.

The addition of copper to the solder composition improves the wettability of the palladium alloys by solder and reduces the solder crystallization interval.

Germanium and gallium additives in the composition of the solder in the above concentrations reduce the melting point of the solder and improve its fluidity and appearance. With an increase in the total germanium and gallium content of more than 10 wt.%, The solder alloy becomes excessively hard and not sufficiently ductile, which complicates its use for soldering.

An example of the preparation of solder.

The solder for soldering palladium and its alloys was carried out in a vacuum induction furnace UIPV-63-10-0.01 company "RELTEC". The calculated amount of gallium and germanium in pieces was loaded to the bottom of the melting crucible made of zirconia, then copper in plates and palladium in compact pieces (see Table 1). The installation was closed with a lid and the furnace chamber was evacuated using a mechanical vacuum pump to a residual pressure of 60 Pa. The furnace chamber was filled with inert gas - argon. The mixture was melted in argon medium. After the components were completely melted, the obtained melt was kept for 5 minutes and drained into a massive copper mold, the bottom of which was protected by a platinum-rhodium substrate.

After cooling, an ingot of the obtained palladium alloy in the form of a squared bar (weighing 3993.8 g or 99.85% of the load) was removed from the mold. The casting at the top had a small shrink shell.

After mechanical cleaning of the surface, the obtained ingot was tested using a milling machine.

Chemical analysis of the sample indicated that the resulting alloy contains 85.21% palladium, i.e. corresponds to 850 sample.

Table 1
The composition of the mixture and the results of melting in order to obtain solder for soldering palladium and its alloys Solder Components Loaded into a melting crucible Mass g % Palladium 3408,0 85,2 Gallium 120.0 3.0 Copper 236.0 5.9 Germanium 236.0 5.9 Total: 4000,0 100.0 The mass of the obtained ingot, g 3993.8 The content of Pd in the obtained solder according to chemical analysis,% 85.21 The interval of melting of solder, ° C 1150-1200 Solder mechanical properties Rolled into a tape 300 microns thick

It was established that the obtained solder has comparative fusibility, fluidity, good wettability with respect to alloys of palladium 850 samples. In the solid state, this solder alloy has high strength and is well polished.

From the obtained casting, square bars were cut, which were rolled “in the cold” using a manual rolling device to 0.3 mm thick plates. The plates were cut into ribbons suitable for manual soldering as solder.

The resulting solder was used for manual soldering during the manufacture of jewelry from alloy palladium 850 samples (in particular, from PDKM 850-10 alloy). Soldering was carried out using a gas burner.

The relative fusibility of the inventive solder allows soldering with slight heating of the connected elements of the jewelry and provides good fluidity of the solder, maintaining the shape of the product and the density of the seam.

The proposed solder has the same fineness in the main component as the brazed jewelry alloy. In addition, the claimed solder can be used - both for soldering products from palladium, and from its various alloys - in cases where it is not necessary to match the fineness of solder and the base of the product.

Claims (1)

Solder for soldering palladium and its alloys containing palladium, copper and other alloying additives, characterized in that the palladium content is 84.5-85.5%, germanium and gallium are used as other alloying additives in the following ratio of components, wt.% : palladium  84.5-85.5 germanium  3.0-7.0 gallium  1.0-6.0 copper  rest, moreover, the total content of germanium and gallium does not exceed 10 wt.%.