Materialographical investigations in the development of a new method of soldering oxide ceramic-oxide ceramic and oxide ceramic-metal joints

The soldering of oxide ceramics after previously metallising the bonding surfaces is a widely used process. In another process, oxide ceramic wetting active solders are used which are however unsuitable for capillary soldering. A new process has been developed in which the ceramic surface to be wetted during the soldering process is first coated mechanically with an active metal (e.g. Ti, Zr, V), thus allowing the prepared surface to be easily soldered. Trials using this process were carried out on Aluminium Oxide and Zirconium Oxide ceramics. As part of the trials the thickness of the Ti-layer after coating was investigated, together with it's ability to be wetted by, Ag(28)Cu, Ag(31.5)Cu(10)Pd and Au(18)Ni solders, and the capillary behaviour of these solders in vertical joints between Aluminium Oxide or Zirconium Oxide and the metallic partners Copper, Nickel and Fe(28)Ni(23)Co. The evaluation of the trials was carried out with the aid of optical light microscopy, scanning electron microscopy and X-ray investigations.