Investment casting

Investment Casting

Investment Casting

Investment casting, also known as lost-wax casting, is a precision casting process used to produce complex and detailed metal components. This technique involves creating a wax model of the desired part, coating it with a ceramic material to form a mold, and then melting out the wax before pouring molten metal into the mold. Investment casting offers excellent dimensional accuracy, intricate detailing, and a high-quality surface finish, making it ideal for producing components with tight tolerances and complex geometries.

Key Features of Investment Casting:

  1. High Precision: Produces parts with tight dimensional tolerances and intricate designs.
  2. Excellent Surface Finish: Minimal need for secondary machining or finishing.
  3. Material Versatility: Can cast a wide range of metals, including stainless steel, aluminum, titanium, and superalloys.
  4. Design Flexibility: Supports thin walls, complex shapes, and fine details.
  5. Minimal Material Waste: Efficient use of material, reducing scrap.

The Investment Casting Process:

  1. Wax Pattern Creation:
    • A wax model is made using a die or mold. For complex designs, multiple wax patterns may be assembled.
  2. Assembly of Wax Tree:
    • Multiple wax patterns are attached to a central wax sprue to form a “tree,” allowing for the simultaneous casting of multiple parts.
  3. Ceramic Shell Formation:
    • The wax tree is repeatedly dipped into a ceramic slurry and coated with fine sand to build a robust shell. Each layer is allowed to dry before applying the next.
  4. Dewaxing:
    • The ceramic-coated wax assembly is heated to melt and remove the wax, leaving a hollow ceramic mold.
  5. Metal Pouring:
    • The mold is preheated, and molten metal is poured into the cavity.
  6. Cooling and Solidification:
    • The metal solidifies as it cools inside the mold.
  7. Shell Removal:
    • The ceramic shell is broken away to retrieve the cast parts.
  8. Finishing:
    • Excess metal is removed, and the casting undergoes machining, polishing, or heat treatment as needed.
Investment Casting