Sand casting
What is Sand Casting ?
Besides investment casting,sand casting is also a new production line in Fly foundry. Sand casting is a mold based net shape manufacturing process in which metal parts are molded by pouring molten metal into a cavity. The mold cavity is created by withdrawing a pattern from sand that has been packed around it. With sand casting process,Fly foundry could make sand castings with materials of Steel, iron, Aluminum.
Basic Steps in Manufacturing Sand Castings
The sand casting process made up of six basic steps:
- 1. Pattern making (including core boxes);
- 2. Core making;
- 3. Sand Molding;
- 4. Melting and pouring;
- 5. Cleaning.
- 6. Delivery
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Patternmaking
—Function of pattern: make sand molds.—Materials: wood, metal, plastic or a variety of others.•Shape and size: the external shape of the cast part but is enlarged by a shrinkage allowance, taper or draft provided on the vertical sides of the pattern, core prints. Sometimes includes gating systems, loose piece.
- Coremaking
- Function: Form the interior surfaces of castings, external shape.
- Tools: Core boxes.
- Shape and size: The same as patterns.
- Function: Form the molding cavity in accordance with casting for pouring.
- Molding consists of all of the operations necessary to prepare a mold for receiving molten metal.
- Operations: packing sand, withdrawing the pattern, setting the cores, assembling the cope and drag halves to close the mold.
- Tools: Flask, pattern, rammer (or molding machine).
- Melting and Pouring
- Function: preparing molten metal for casting, pouring molten metal into mould.
- Tools: Furnace (cupola, crucible furnace, electric furnace), ladle.
- Cleaning
- The complete process of the cleaning of castings, called 'fettling', involves the removal of the cores,gates and risers, cleaning of the casting surface and chipping of any of the unnecessary projections on surfaces.
- Delivery
.Package the sand castings with standard wooded cases and deliver to customers’ destination port by sea or air.
Usually used sand casting processes are green sand casting, resin sand casting, precoated sand casting.