Compounds made of ceramics and aluminum alloys are interesting for lightweight constructions because unique properties can be combined. High stiffness, hardness (wear resistance) and chemical stability of ceramics are interesting, especially in areas where the construction is subject of higher loads. The potential of the various materials can be exploited, if the joint comply the requirements for strength and gas tightness. The brazing process is challanging, due to different microstructures. Thermal stress caused by different CTE reduces strength and promotes early failure. Further, insufficient wetting of solders on Al_2O_3, ZTA, Si_3N_4, SiC cause defects like pores inside the metallic solder layer and limits strength. To overcome these barriers, a previous deposition of titanium on the ceramic surface is established. Alternativelly, based on the mechanism, active brazing has been developed. The prior coating step can be omitted, by adding the active element to the solder. The reaction layer is formed in situ at temperatures ≥750℃ and exhibits excellent bonding with the ceramic. Temperature should not exceed 550℃ to prevent thermal degradation for brazing of aluminium based alloys.
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