Vacuum furnace brazing eliminates the need for fluxes to protect braze joint surfaces from oxidation. Thermal-Vac's vacuum brazing is conducted at 10-4 to 10-6 torr vacuum levels. At these vacuum levels, coupled with brazing temperatures, the vacuum furnace atmosphere is neutral or even slightly reduced (thereby tending to clean the joint surfaces of oxides). If the materials being brazed require post braze heat treatment, the braze and heat treat furnace cycles can potentially be combined. Furnace brazing also allows for precise control of the entire brazing cycle, and (with the aid of imbedded or attached thermocouples) ensures an exacting braze joint temperature. Thermal-Vac has a multitude of vacuum furnaces from which to choose.
Vacuum brazing is ideal for base materials such as stainless steels, nickel alloy, titanium, and copper alloys. Typical braze filler metals are nickel, gold, palladium, copper and silver. If copper or silver filler metals are used, the vacuum furnaces are filled with a partial pressure of argon inert gas to maintain the pressure in the furnace higher than the vapor pressure of the filler metal.
Industry standards for vacuum brazing include:
- Mil-B-007883C, Type II
- AWS C3.6: 1999
