Why Vacuum Casting
Superalloys contain reactive elements (aluminum, titanium, niobium, hafnium) that form harmful oxide inclusions when exposed to atmospheric oxygen during melting and pouring. These inclusions act as fatigue crack initiation sites, drastically reducing the component's fatigue life and making it unsuitable for safety-critical applications. Vacuum induction melting (VIM) eliminates this problem by melting and pouring the alloy in a high-vacuum environment (typically below 10 microns of mercury). The result is a casting with maximum metallurgical purity, optimized grain structure, and mechanical properties that meet the most stringent aerospace specifications.
Our VIM Casting Process
CastAlloy's vacuum investment casting process begins with precision wax pattern creation through injection molding, followed by ceramic shell building through multiple dipping cycles. The shell is dewaxed in a steam autoclave, then pre-heated to casting temperature. Superalloy charge materials are loaded into a VIM furnace, melted under vacuum, refined (composition adjustment and degassing), and poured into the pre-heated shell through a vacuum-sealed pour system. Post-casting operations include shell removal, hot isostatic pressing (HIP) to close any residual microporosity, heat treatment per the applicable AMS specification, and precision machining to final dimensions.
Alloys and Applications
We vacuum cast all major superalloy families including Inconel (718, 625, 713C), Hastelloy (X, C-276), Waspaloy, MAR-M-247, Stellite grades, and titanium alloys. Applications span gas turbine hot-section components, nuclear reactor internals, chemical processing equipment, and any application where oxide-free castings are required. Component weights range from a few grams to nearly one metric ton. Contact us for a vacuum casting quotation.