Vacuum cast alloys are created through vacuum induction melting, which was initially developed as a method to refine alloys like nickel and cobalt – but is now more widely used as these materials have become more common. Vacuum cast alloys still tend to be nickel and cobalt-based, but have other elements within their chemistry that are not conducive to being manufactured via a conventional air melting process.
Many of these alloys offer high levels of cleanliness and a variety of properties that allow them to be used in numerous manufacturing applications, such as melting metals for the aerospace and nuclear sectors. Vacuum induction melting might have initially been developed to create superalloys, but it can also be used for stainless steels and a range of other metals.
THE BENEFITS OF USING VACUUM CAST ALLOYS
Vacuum induction melting allows the good homogenisation of the melt, and it is usually used for processing high purity metals with tight tolerances. Other advantages include:
- Flexibility with regards to batch size
- Accurate temperature control
- Removal of dissolved gases like hydrogen
- Creating very close compositional tolerances
- High reliability and high productivity
Vacuum induction melting can have several applications, including casting aircraft components, high integrity and complex valves for harsh environments, and electrodes for re-melting.
In the past, vacuum casting tended to be used more for aerospace applications but, in today’s environment, it is used extensively in all types of manufacturing process. Here at Dean Group, we welcome the challenge to meet and exceed your expectations when it comes to vacuum cast alloys.
VACUUM INDUCTION MELTING PROCESS
In this metallurgic process, metal is melted via electromagnetic induction under vacuum. Electrical eddy currents are used to make the melting process possible, which wouldn’t happen via other melting processes – this is because certain metals and alloys have an affinity for oxygen and nitrogen, so they cannot be melted in air.
Inside a vacuum chamber, there is an induction furnace that contains a refractory lined crucible enclosed by an induction coil. The furnace is air-tight and has the ability to withstand the required vacuum for processing.
Typically, the metals used in vacuum induction melting have melting points of up to 1800oC.