Investment casting

Investment casting is a metal-forming process in which a disposable ceramic shell is built around a wax pattern, then heated to remove the wax and filled with molten metal.

Wax pattern: A shaped wax replica used to form a cavity in a ceramic mold. Its geometry becomes the metal part after the wax is removed.
Turbine blade: An airfoil-shaped component that extracts energy from a flowing gas in a turbine. Investment casting makes intricate blade shapes, including internal cooling passages.
Sand casting: A metal-casting process that uses a mold made primarily from bonded sand. Sand casting usually handles larger parts more economically, but gives coarser surfaces.
Refractory material: A material that retains useful properties at high temperatures and resists chemical or physical breakdown. Ceramic shells rely on refractory materials to survive contact with molten metal.
Dimensional accuracy: The closeness of a manufactured part’s dimensions to specified values. Pattern fidelity and shell behavior set the achievable accuracy of an investment casting.
Ceramic shell molding: A mold-making method that builds a refractory ceramic shell by repeatedly coating and drying a pattern assembly. It creates the disposable mold that contains the molten metal.
Dental casting: The production of dental restorations by pouring alloy into a mold formed around a pattern. The process can reproduce small, detailed metal restorations.
Die casting: A process that forces molten metal into a reusable metal die under pressure. Its reusable tooling suits high-volume production, unlike investment casting’s disposable shells.
Ceramic: An inorganic, nonmetallic material hardened by heat, often resistant to high temperatures and wear. Ceramics provide the heat resistance and stiffness required of the mold shell.
Surface finish: The texture and irregularities present on a material’s surface. A smooth pattern and fine shell can yield surfaces needing little finishing.

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