Can Ceramics Be Resistance Brazed

Corrosion behavior of ceramic brazed joints is criti cal.

Can ceramics be resistance brazed.

Ceramics will only occur at temperatures above about 750ºc depending upon the composition of the ceramic that is to be brazed. Section 12 8 describes the microstructure and strength behaviour of an active brazed metal ceramic compound for a selected example. Resistance with excellent electrical insula tion properties. This metallization can also be brazed in oxidizing atmospheres with a wider alloy selection than active metal alloys.

For example if nickel plated moly manganese bonds can be brazed in wet or dry hydrogen high vacuum or just about any inert atmosphere. In general nitride and carbide can be more easily wet than the oxide ceramic types. The technologies developed to perform joining of ceramics to themselves or to other materials are different from most other brazing processes. Metal to ceramic brazing can be accomplished by first applying a metallic layer onto the ceramic surface or by braz.

However the brazing filler metals often used to braze ceramics have infe rior corrosion resistance. Ceramics by nature are highly corrosion and oxidation resistant materials. Ceramics as everybody knows are hard and brittle with nil ductility and limited tolerance for tensile stresses. Further examination methods for metal ceramic compounds are for example testing gas tightness thermal shock resistance creep resistance and oxidation resistance.

The microstructure of an active brazed metal ceramic compound is described and. Typically the ctes of ceramics are less than most metals and braze alloys which means on cooling from the brazing temperature the braze alloy and metal component will contract more than the ceramic component. Thus in all cases the assemblies that are to be joined have to be heated to at least this temperature. Many times the brazing filler metals form intermediate phases with the.

3 au cu brazed metal to ceramic sample made using thin film metallization. This will introduce residual stresses into the joint. In general brazing also produces less thermal distortion than welding due to the uniform heating of a brazed piece. Although used as thermal insulators they are sensitive to thermal shocks.

Additionally dissimilar metals and non metals i e. Complex and multi part assemblies can be brazed cost effectively. Metalized ceramics can be brazed. Therefore if possible ceramics are designed to be stressed in compression.