Advanced Ceramics for
High-Tech Industries
Produkte : Keramik-Metall-Verbindungen
Es gibt unterschiedliche Fügeverfahren, um einen Bauteil aus Keramik mit einem aus Metall zu verbinden. Wenn die Anwendungen erfordern mechanische Beständigkeit, hoch Temperaturbeständigkeit, Ultrahoch-Vakuum Dichtung und Korrosionbeständigkeit sind die dichte Hartlöten unumgänglich.
Anwendungen
Keramik-Metall-Lötverbindungen sind für sehr anstregende Umwelt geeignet wie :
- Elektronik für Luft-und-Raumfahrt (civil und militär)
- Verteidigunggeräte
- medizinische und analytische Instrumente
- Ultrahoch-Vakuum
- Atomkrafindustrie
PNL INNOTECH hat eine vollständige Erfahrung bei diesen Bereichen, damit ihrer Technologie eine Anwendung in alle Branchefinden kann.
Produkte
The product range that PNL INNOTECH can offer is not restricted to the here below list since the company mainly manufactures customized ceramic to metal brazed assemblies. For instance :
- high-voltage feedthroughs for the mass spectrometry, ion guns
- electrical feedthroughs for medical implants – cochlear and heart pace makers
- hermetic packages for airborne electronics, analytical tools and devices for the oil industry,
- high-voltage hermetic connectors for the nuclear industry,
- high-voltage insulators for electron tubes.
Werkstoffe
Not all advanced ceramics can be brazed. There are mainly :
- aluminium oxide (alumina, saphirre,rubi) and beryllium oxide,
- and to a lower extent aluminium nitride, silicon nitride, silicon carbide, boron carbide, zirconia…
The metal associated with the ceramic must have a close CTE – coefficient of thermal expansion – in order to minimize residual stresses in the joint that would lead to rupture. The following metals are most commonly used :
- kovar, copper, titanium, nickel-iron, stainless steel, molybdenum, niobium, platinum…
The braze alloy to be used will depend upon various parameters : final temperature of use of the product, nature of the metal to be joined, several metals of different kinds to be brazed. The following alloys Ag-Cu, Ag-Cu-Pd, Ag-Cu-Au, Au-Cu, Au-Ni, Ag, Au, Cu are typical and cover a range of temperatures from 780°c to 1100°c.
A ceramic to metal assembly can be done in various ways, but all of them require that a metal interlayer be deposited so that the adhesion of the subsequent brazing will be possible :
- sintered thick layer of molybdenum-manganese, only with oxide ceramics (alumina, beryllium oxide..)
- thick layer of a reactive metal that chemically reacts
- thin layer of W-Ti for instance deposited by PVD process.
PNL INNOTECH can offer these three technologies. The choice for one of these will depend upon the brazed assembly design to be manufactured, the conditions of use or the cost requirements.
