ISM is a method of melting metals in a segmented, water-cooled copper vessel, under vacuum or controlled atmosphere in an induction coil.

Advantages
• For reactive metals which cannot be melted in a refractory crucible due to metal/crucible reactions, ISM offers a water cooled metal container which does not react with the melt. Unlike the alternative Vacuum Arc Skull Melting process which requires the charge to be in the form of an electrode, ISM can be charged with chunks, plates, turnings, high purity sponge or mixtures of these material forms. This greatly reduces the cost of the charge material

• For super clean superalloys and other metals that are required to have a very low inclusion content, ISM eliminates the problem of inclusion pickup from the crucible

• For degassing of the metal charge, volatilising of low vapour pressure impurities and pouring of gas-free castings, ISM can be operated in vacuum

• For melting alloys with high vapour pressure alloying elements, ISM can be operated in an inert atmosphere at a pressure that eliminates or minimises alloy loss

• A wide variety of alloys can be melted successively in the same crucible with no fear of chemical cross contamination

• The intense stirring generated by the magnetic field fuses any high melting temperature charge components and homogenises the melt in both chemical composition and temperature. This translates into faster melt down, better mold filling (for castings) and a higher quality product

• The elimination of the ceramic crucible eliminates the need for downtime due to crucible replacement, thereby increasing furnace productivity.