We’ve already discussed pressure die casting and lost foam casting. So, to continue our discussion of modern casting, we will now look at centrifugal casting. Of course, to begin the discussion, we will define types of centrifugal casting.
Centrifugal casting is the process of pouring molten metal into a rotating mold. Centrifugal casting can be carried out on either a vertical or horizontal axis (direction). The difference in the rotational direction of metal flow into the mold cavity produces different characteristics depending on the direction used.
Because centrifugal force is generated by a rotating mold, this type of casting is known as centrifugal casting. We use metal molds to cast using the centrifugal casting method (die casting).
Metal liquids that acquire centrifugal force freeze faster due to their faster heat release and form products that correspond to their molding cavity.
Centrifugal casting consists of three types: true centrifuges, semi-centrifuges, and centrifuges. Here is the explanation.
Types of Centrifugal Casting
1. True Centrifugal
In true centrifugal casting, molten metal is poured into rotating molds to produce relatively simple tabular (cylindrical) casting products, such as pipes, tubes, bushings, and objects that have radial symmetry. This method produces casting products that have a directional freezing direction from the outer diameter to the inner diameter.
The working principle of true centrifugal casting is when molten metal is poured into a mold that is rotating at a low turning speed, after the full mold the rotation is raised to a certain rotational speed and held until the molten metal freezes.
The characteristics of true casting products are as follows:
- The product has a high density, especially on the outside of the casting surface
- No shrinkage of freezing occurs on the outside due to the presence of centrifugal force acting continuously on the surface
- Due to the presence of centrifugal force, the slag will be on the inner wall of the casting, this slag can be removed by machining.
2. Semi Centrifugal
The semi-centrifugal method produces cast objects in the shape of a solid and has radial symmetry. The working principle of vertical semi-centrifugal casting is to start pouring at the moment when the mold is stationary. When the molten metal is fully filled into the mold, then the mold is rotated to a certain speed so that metal freezing occurs at the moment when the mold rotates. Due to the centrifugal force, the molten metal enters the entire cavity of the mold, until the metal liquid freezes in the mold.
Semi-centrifugal casting is used to produce workpieces that have a length of about 100 mm. The use of semi-centrifugal casting has a wider range because the outer casting products have a greater density compared to the density of the middle part. Because the density of the middle is low, if you make an object with a hole in the middle, it will be easy to work with machining. The results of semi-centrifugal cast products can make relatively complicated workpieces such as wheels, pulleys, drums, and so on.
3. Centrifuge
In the centrifuge method, the printed cavity is outside the center of rotation, so that the molten metal poured into the mold will be distributed into each mold cavity in a centrifugal style, as shown below.
The working principle of centrifuge casting begins after the molten metal reaches the desired pour temperature, then the liquid is poured into the pouring dish. The resulting centrifugal force will push the distributed metal liquid into the molding cavity evenly. The rotation continues until the molten metal freezes inside the mold.
We can use centrifuge casting for small cast objects. And it does not require radial symmetry requirements like the two methods above.
Okay, that’s the discussion about centrifugal casting and its types. For questions and more info, you can tell us in the comments column or contact our Team directly.