What is Casting?

Casting is a manufacturing process where a liquid material is poured into a mold and allowed to solidify into a specific shape. It’s like making a sculpture but using materials like metals or plastics instead of clay!

Types of Molds in Casting

There are two main types of molds used in casting: expendable molds and permanent molds.

Expendable Molds

Expendable molds are molds that are used only once for each casting. After pouring the material in and letting it harden, the mold is destroyed to remove the casting. Here are some types of expendable molds:

• Sand Mold Casting: Sand mixed with a binder is shaped into a mold. It’s often used for metal castings.
• Shell Mold Casting: A thin layer of sand is applied to a heated pattern, creating a shell-like mold.
• Expendable Pattern: The pattern (the original shape) is made of a material that can be melted away, creating the mold.
• Plaster Mold Casting: Plaster is used to create molds, which is suitable for non-ferrous metals.
• Lost Wax Casting: A wax pattern is coated in a ceramic shell, the wax is melted away, and molten metal is poured into the shell.
• Vacuum Casting: A mixture is poured into a mold and then vacuum is applied to pull out air bubbles.

Permanent Molds

Permanent molds can be reused many times because they are made from materials that can withstand high temperatures. Here are some common types of permanent molds:

• Permanent Mold Casting: Metal molds are used to produce durable items, often for mass production.
• Slush Casting: This method is used to make hollow objects by pouring metal into the mold and then pouring it back out before it fully solidifies.
• Pressure Casting: Liquid metal is injected into the mold under high pressure, which helps fill thin sections.
• Die Casting: This is a high-pressure method used for metals, creating parts that are very detailed and smooth.
• Centrifugal Casting: Molten metal is poured into a rotating mold, which helps distribute the metal evenly.
• Squeeze Casting: This combines casting and forging, where molten metal is filled into a mold under pressure.

Conclusion

Understanding these mold types can help you learn about how different products are made. Whether it’s a toy, a car part, or a piece of jewelry, casting has a place in creating a wide range of items!