Vacuum brazing and active metal brazing are particularly well suited to the joining of:
Nickel and Iron based alloys containing aluminum and/or titanium
Ceramics & metal to ceramics
Exotic base metals such as Aluminum, Titanium, Zirconium, Niobium, Molybdenum, and Tantalum
Instead of using a protective and deoxidizing inert gas, vacuum brazing is fluxless and is performed at high temperatures and in a high vacuum atmosphere with pressures typically in the x 10-5 range. Vacuum brazing also deoxidizes the metals being brazed, but more importantly eliminates undesirable reactions that would have occurred in hydrogen brazing and helps to vaporize or remove high vapor pressure materials that are seen as contaminants in high vacuum applications. Vacuum brazing or even vacuum firing can be used to remove hydrogen gas from materials like stainless steel, which were previously brazed in hydrogen. Vacuum brazing is also sometimes favored over hydrogen brazing when brazing very large parts because of the ability to purge occluded, close fitting areas.
Many of the same filler metals or braze alloys used in Hydrogen brazing are also used in vacuum brazing and like Hydrogen brazing, we also braze common materials like silver, copper and stainless in vacuum.
Our vacuum furnaces are cold-walled retorts having either a graphite or Moly hot zone. Most furnaces use ultra clean cryo pumps, while a few use also very clean turbo pumps to achieve high vacuum. We have vacuum furnaces of all sizes and our largest vacuum furnace has a 48” diameter hot zone. Active Metal Brazing is an excellent alternative to ceramic metalizing because of its lower cost and shorter lead times. It is brazed in a high vacuum and results in strong hermetic bonds between ceramic and various metals. Active metal alloys typically include titanium or aluminum, which when correctly heated, form bonds with virtually any ceramic-like material.