Shenzhen Alu Rapid Prototype Precision Co., Ltd.

Metal casting is a fundamental manufacturing technique used to produce complex metal parts by pouring molten metal into a mold cavity, allowing it to cool and solidify into the desired shape. This process has been used for thousands of years and is versatile for creating everything from engine blocks to jewelry, enabling the production of intricate designs that would be difficult or costly with other methods like machining.

Basic Steps in the Metal Casting Process

The process generally follows these sequential steps, though variations exist depending on the specific type of casting:

1.Patternmaking: A reusable pattern (often made of wood, plastic, or metal) is created in the shape of the final part. This pattern is used to form the mold cavity.

2.Mold Creation: The pattern is placed in a molding material (like sand, plaster, or ceramic) to form a two-part mold (cope and drag). Cores may be added for internal voids or holes.

3.Melting the Metal: Raw metal is heated in a furnace until it becomes molten, typically reaching temperatures of 1,000–1,600°C (1,800–2,900°F) depending on the alloy (e.g., aluminum, iron, or steel).

4.Pouring: The molten metal is poured into the mold through a channel called a sprue, filling the cavity completely. In some processes, pressure or vacuum assists the flow.

5.Cooling and Solidification: The mold is allowed to cool naturally or with controlled methods, causing the metal to harden and take on the mold's shape. This step can take minutes to hours.

6.Extraction and Finishing: The solidified casting is removed from the mold (often by breaking the mold if it's expendable). Excess material (gates, risers) is removed, and the part undergoes cleaning, heat treatment, or machining for final tolerances.

Common Types of Metal Casting

While the core process is similar, different methods suit various applications:

Sand Casting: Uses sand molds for large, low-volume parts; inexpensive but rough surface finish.

Die Casting: Forces molten metal into reusable metal dies under high pressure; ideal for high-volume, precise parts like automotive components.

Investment Casting: Involves wax patterns coated in ceramic, then melted out; produces highly detailed, smooth parts.

Other Variants: Include permanent mold casting, centrifugal casting, and continuous casting for specialized needs.