Vacuum Brazing is a process to join metal parts together with an alloy, in an environment that is less than normal pressure. Low pressures are created via vacuum pumps on a sealed chamber. Partial Pressure Vacuum Brazing is performed in the 10-2 to 10-4 torr level. The pumps are turned on fully and are set to reach the 10-6 torr range. Meanwhile an inert gas such as argon is flowed into the chamber to increase the pressure to the desired range.
Partial Pressure Vacuum Brazing is usually a better option for copper and copper alloys than Hard Vacuum, due to the low vapor pressure of copper. Other materials where partial pressure is a better environment are brass, silver and nickel.
Hard Vacuum is any vacuum less than 10-4 torr. ThermoFusion routinely brazes in the 10-5 torr or lower range. Metals brazed in this range include stainless steel, titanium, Inconel, Incolloy, Waspalloy, and other high-nickel alloys.
|Torr (mm Hg)
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||PSIA (lbs/sq.in. absolute)