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4 Different Types of Metal Casting Process

Metal casting process is a manufacturing process in which metal are melted to be poured in a cavity. Casting has been done for ages, ever since production of parts came to existence. In today’s article, you’ll get to know the types of metal casting process that exist. Some of these casting processes are used for producing certain type of item. While, some are used to produce complex parts. Casting process can be typically used to produce large variety of parts that are used in different industries. Different types of casting process lead to production of certain casting quality, complexity, properties, manufacturing cost, surface finish, dimensional accuracy, etc. All these properties are considered when selecting suitable type of casting process for an item.

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Types of metal casting process

The major and most important types of casting process used in the manufacturing industries are the following:

Sand casting

Sand casting process is a manufacturing process that uses sand to create a mold cavity. Sand serves as refractory material that is able to resist a molten metal. Green sand is usually implied because it has good binding properties, such as, sand, clay, silica, and little amount of water. Pattern made of either wood or metal is used to create a good replica or model of the item to be produced, leaving same shape in the mold cavity. Patterns are created to be slightly larger than the original item, to contract the molten metal during cooling.

Sand casting is normally used when larger part is needed to produced, its production is relatively inexpensive, especially when producing low-volume. Sand casting process offers low cost for post-casting tooling, and ferrous and nonferrous metals can be used for casting. However, sand casting produces a comparative rough surface, as its required finish work. It also yields a lower degree of accuracy. Sand casting process is slow, as the mold must be break when bringing out the casting.

Read full article on Sand casting: how it is done from pattern making to trimming

Type of metal casting process

Die casting

Die metal casting process usually involves nonferrous metals and alloys, such as, tin, zinc, aluminum, and copper. Its end product offers better surface finish, and good dimensional accuracy. This metal casting process is carried out by forcing molten metal into a mold at high pressure. The mold is coated with a lubricant, for easy injection of the molten metal. And to regulate the die’s temperature. molten metal is rapidly injected into the die under high pressure. Rapid insertion helps to prevent segment of the casting from hardening before its remaining part. After the molten metal solidifies, the casting is taking out of the die, then the craps materials will be cutoff.

Die casting process has relatively high tooling costs, making it more cost-efficient when producing high-volume. Porosity defects are common in die casting, when producing large items, because its entrapped air and due to the solidification of the molten metal before it reaches the die cavity.

Types of metal casting process

Investment casting

Investment casting is another type of metal casting process, that offers high degree of accuracy, and dimensional results, relatively high-quality surface finish. It is capable of creating thin-walled parts with complex geometries. Just as sand casting, investment casting also has the capacity of casting both ferrous and nonferrous metals.

The metal casting process uses disposable wax, usually beeswax to create a pattern or model of the casting. The pattern (wax) is placed into the mold. The wax is pre-coated with a liquid refractory material, dried in sun or heated before placing into the mold, helping the pattern to be able to resist the molten metal for little amount of time. After the injection of the coated-wax into the mold, molten metal is poured and its takes position of the pattern. The pattern melts out and the metal solidifies taking the shape of the melt out wax.

Investment casting is widely used in manufacturing of aerospace, automotive, and military parts.

Process of investment casting

Centrifugal casting

Centrifugal casting is a special type of casting process that is implied when durability of a product is important, internal diameter of a casting to have fine grains, and generally, where hollow parts needed. Centrifugal casting is carried out in a permanent mold, that allow molten metal to be poured to it. The mold spins at high speed around its axes. Due to the centrifugal force, molten metal is throw towards the mold walls. It solidifies and the casting is take out of the mold.

Centrifugal casting process are performed when a part such as, spherical glass objects, pipes, flywheels, boilers, television picture tubes are needed.

Working principle of centrifugal casting

And that is it for this article, types of metal casting process. Am sure you’ve attained the knowledge. Ask questions via my comment box, if you have any and please don’t forget to share on your social media platform. Thanks for reading!

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