High vacuum brazing with CERABRAZE VAC 780 L10

CERABRAZE VAC 780 L10 is suitable for high temperature brazing of diamonds, ceramic-metal composites, ceramic, saphire, graphite, aluminum, zircon and beryllium to normal substrates like sintered hard carbide, stainless steel and other materials without the use of molybdenum manganese or other metallization methods. Sintered hard carbide is the substrate of choice for diamonds due to it ́s still acceptable thermal expansion coefficient. The cohesiveness of the soldered connection, that can be attained by using CERABRAZE VAC 780 L10 active brazing paste, depends on the carrying materials, the temperature as well as the quality of the used vacuum.

In general it’s safe to say that no failures of the produced cohesion with diamonds (or ceramic) will occur subject to optimized brazing parameters.


Application


When using the active brazing paste CERABRAZE VAC 780 L10 we recommend a brazing temperature of 810°C plus approx. 30°C, to attain a solid cohesion with diamond. 15°c degrees over solidus temperature is only enough if a exact and precise temperature measurement is possible.

Brazing temperatures higher than the liquidus-temperature improve the ability of wetting. Possible brazing atmospheres are pure Argon (4,8 respectively 99,998% purity) or vacuum (better than 5x10-4 mbar). When using vacuum brazing the temperature must not exceed 900°C to avoid the evaporation of silver. Active brazing pastes do not flow on ceramics therefore the paste has to be applied to the surfaces to be brazed. CERABRAZE VAC 780 L10 active brazing paste is also suitable for silkscreen printing applications using mesh openings between 170 and 230 mesh.

The information about the products are based on extensive research and application-specific experience. CERABRAZE VAC 780 L10 can easily be dosed by using a automatic metering unit. We recommend a vacuum of at least 4x10-5 or higher.

Typical brazing cycle (varies with loading and size of the furnace)
 

  1. Heat up to 760°C (20 Kelvin/minute)
  2. Hold for five minutes
  3. Heat up to 905°C (20 Kelvin/minute)
  4. Hold for 6 minutes


Note:

We provide these results to the best of our knowledge. We do not assume liability. Due to continuous product development we reserve the right to make technical changes. We gladly offer further consulting as well as participation in finding solutions to production and application problems. This does not release the user of his responsibility to check our information and recommendations for applicabilty in his own production process. This applies also for third party trade mark rights as well as applications and procedures which are not particularly specified by us. In the event of damage our liability is restricted to the same level of compensation effective for quality failure as stated in our terms of delivery and sale.