Breviary Technical Ceramics


      Joining and Bonding Techniques

 Active Soldering

Active soldiers typically melt at between 600 and 1,000°C, and are processed at between 800 and 1,050 °C.
Active soldering makes it possible to solder directly to ceramic without an additional metallisation process. These solders are metallic, the compositions of which alloys permit them to wet non-metallic inorganic materials. They contain components such as titanium, zirconium or hafnium that react with ceramics.

Special attention is called for by the active soldering process, since the solders do not flow like conventional solders, and the capillary effect cannot be used. Active soldering in a furnace must, however, be carried out in a carefully monitored furnace atmosphere.
The process of active soldering is achieved through the high reactivity of titanium. During the soldering process, a thin yet continuous reaction layer forms on the surface of the ceramic, providing the necessary adhesion.

Active soldering systems typically consist of silver/titanium, silver/copper/titanium, or silver/copper/indium/titanium. The soldering is usually carried out under argon or in a vacuum.

In addition to aluminium oxide and aluminium nitride, almost any other ceramic and metals that are not easily wetted may be soldered. Actively soldered joints are therefore appropriate in the machine construction sector.

Solders for various ceramics are available on the market.


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