Vacuum furnace – [ˈvækjum ˈfɜrnəs] – a furnace in which metal is processed (heated, melted) under vacuum. Melting V.f. used for the production of chemically active and low-melting metals, as well as high-quality steel alloys. For melting alloys of special quality, electron beam and plasma arc furnaces are used.
EX: The object is exposed to temperatures of around 900ºC in a vacuum furnace