Vacuum induction melting furnace (VIM)
CONSARC

The Vacuum Induction Melting (VIM) Process, initially small vim furnace used to meet alloy requirements of specialized industries, is becoming more and more essential in the production of high performance materials for many industrial applications. VIM melted alloys are used in very demanding situations, including Nickel based super alloys for high temperature applications, stainless steels for nuclear applications, Cobalt based alloy for medical applications, high purity copper alloys and very clean magnetic alloys for high permeability.

The VIM process involves the melting of metals by means of electromagnetic induction while under vacuum. Melting takes place within a furnace consisting of a refractory lining or crucible inside a water-cooled induction coil. The furnace assembly is completely enclosed by a fabricated steel, water cooled furnace chamber that is evacuated by a series of vacuum pumps so that the charge may be melted down, refined and poured into molds under vacuum or inert gas.

This process permits the refining of metals and alloys that contain elements having a strong affinity for certain gases such as oxygen. Chemical reaction, dissociation and flotation remove dissolved and chemically bonded impurities. Melt chemistry can be accurately adjusted thereby producing an end product that is clean and homogeneous.