Vacuum brazing is a term for various metal joining or brazing processes that take place in a chamber or retort below atmospheric pressure, otherwise known as a vacuum furnace. Vacuum brazing is brazing in a furnace using a vacuum atmosphere.

A vacuum furnace is a furnace using low atmospheric pressures instead of a protective gas atmosphere like most heat treat furnaces. Furnaces are categorized as hot wall or cold wall, depending on the location of the heating and insulating components. Cold wall furnaces are used in vacuum brazing.

Assemblies are bright and clean (shiny) after vacuum brazing because the extremely low amount oxygen in a vacuum atmosphere prevents oxidation of parts. Vacuum brazing is particularly useful where base metals are processed that adversely react with other atmospheres, or where entrapped fluxes or gases are intolerable. Vacuum brazing is widely used to braze base metals of stainless steel, super alloys and carbon low alloy steels.

Vacuum brazing offers the combination of high cleanliness and uniform heating and cooling or rapid cooling. Vacuum brazing is ideal for oxidation sensitive materials such as those used in the aerospace industry, precision instrument and systems. SAMT is also providing this niche service to cater for the demand of such customers.