Process for the production of a soldered joint

A process for the production of a soldered joint between a carbon part and a silicon carbide part, via a silver-titanium solder, having a titanium content in the range of 2-6% by weight, wherein the solder is interposed between the carbon part and the silicon part in a vacuum furnace, the process comprising:

• heating in a first step, a combination, formed of the carbon part, the silicon carbide part and the interposed solder, to a temperature just below the melting temperature of the solder, at a rate of less than 600.degree. C./hour;
• further heating, in a second step, the combination to the actual melting temperature of the solder which, depending on the composition of the solder, is in the range between 1000.degree. and 1050.degree. C., at a rate in the range of 200.degree.-1000.degree. C./hour;
• further maintaining, in a third step, the combination, at a predetermined soldering temperature between 1000.degree. and 1050.degree. C. for a soldering time between 5 and 20 minutes;
• cooling, in a fourth step, the combination, to an intermediate temperature, with the intermediate temperature being below the melting temperature of the solder, at a rate of less than 200.degree. C./hour;
• and
• further cooling, in a fifth step, the combination from the intermediate temperature to ambient temperature, at a rate of less than 400.degree. C./hour,
• wherein the carbon part is comprised of synthetic graphite.

A process for the production of a soldered joint between a carbon part and a silicon carbide part, via a silver-titanium solder, having a titanium content in the range of 2-6% by weight, wherein the solder is interposed between the carbon part and the silicon part in a vacuum furnace, the process comprising:

• heating in a first step, a combination, formed of the carbon part, the silicon carbide part and the interposed solder, to a temperature just below the melting temperature of the solder, at a rate of less than 600.degree. C./hour;
• further heating, in a second step, the combination to the actual melting temperature of the solder which, depending on the composition of the solder, is in the range between 1000.degree. and 1050.degree. C., at a rate in the range of 200-1000.degree. C./hour;
• further maintaining, in a third step, the combination, at a predetermined soldering temperature between 1000.degree. and 1050.degree. C. for a soldering time between 5 and 20 minutes;
• cooling, in a fourth step, the combination, to an intermediate temperature, with the intermediate temperature being below the melting temperature of the solder, at a rate of less than 200.degree. C./hour;
• further cooling, in a fifth step, the combination from the intermediate temperature to ambient temperature, at a rate of less than 400.degree. C./hour,
• wherein the silicon carbide is comprised of a carbon-doped silicon carbide.