Investment Castings are known for their high quality, intricate details, complex shapes, accurate dimensions and smooth surfaces. But did you know that investment castings typically require much less machining and other post-cast processing than conventional castings or fabricated components? This makes machined investment castings a good choice for design engineers looking for high-strength and lightweight components with reduced lead times, waste and energy costs.
Although achieving “net-shape” or “near-net-shape” cast components drastically reduces secondary processing costs, some engineers require machined investment castings due to precise dimensional requirements, tight tolerances, specialty profiles, tapped holes, etc. Typically, standard Investment Casting tolerances are +/-0.010” for the first inch and +/- 0.005” for each succeeding inch. During the design for manufacturing process, Investment Casting engineers can reduce or eliminate machining previously required on sand castings, fabrications or forgings. If machining is still needed, the machining requirements of an investment casting will be less than for sand castings or welded fabrications.
The name investment casting is derived from the process of a pattern being “invested” or surrounded with a refractory material to create a mold. The pattern, made of wax or a 3D printed material, is melted away to create a hollow cavity in the mold into which molten metal is poured. Investment castings can weigh anywhere from a few ounces to several hundred pounds.
The type of machining process needed varies depending on how the machined investment castings will be used. For example, the aerospace and power generation industries use machined investment castings for many safety-critical applications that require high-strength in extreme environmental conditions. In these industries, it is important to ensure strict tolerances are achieved by casting and machining the metal components to exact specifications.
Different machining equipment and tooling is used to achieve a part’s final configuration. These machining processes include:
Turning – A single edge cutting tool is used to remove excess material from a rotating component to create a cylindrical shape.
Drilling – A round hole is created in the casting.
Boring – A single point tool is used to improve the accuracy of an already roughly made hole.
Reaming – A small amount of metal is removed from an already drilled hole to achieve a tighter finished tolerance.
Milling – A rotating tool with several cutting edges creates a straight surface.
When it comes to making high-quality metal components, machined investment castings can provide a high return on your investment! Used for thousands of years, the investment casting or lost-wax process is now the future of manufacturing. Here’s just a few of the benefits:
Barron Industries is a global supplier of precision cast parts, machined components and complete assemblies. Barron manufactures highly-engineered investment castings with both ferrous and non-ferrous metals. Using the most advanced casting and CNC machining technology, Barron’s start-to-finish manufacturing process includes everything from design for manufacturing to in-house Nadcap certified NDT and welding, as well as off-shore production and complete supply chain management.
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