Centrifugal Casting: An Analysis of the Core Casting Technology Driving Modern Industry

A precision process called "centrifugal casting" is playing an increasingly critical role in modern manufacturing in the pursuit of higher performance and more durable parts. Compared with the well-known traditional sand casting, centrifugal casting has occupied an irreplaceable position in specific industrial fields by virtue of its unique principle and excellent product performance. We will delve into what centrifugal casting is and compare it with traditional sand casting to explore its advantages and disadvantages as well as the main application products.

What is centrifugal casting?

Centrifugal casting is a technology that uses centrifugal force to form castings. Its core principle is to pour molten metal liquid into a high-speed rotating cast (usually a metal mold), and under the action of strong centrifugal force, the metal liquid is closely pushed to the inner wall of the cast, thus forming hollow, uniform wall thickness of the tube, ring or symmetric shape casting. This process is similar to how we quickly spin a bucket of water, and the water will be firmly pressed against the wall of the bucket without spilling.

Strong centrifugal force not only completed the filling and forming, crucially, it can effectively promote the order of metal solidification, and the density of smaller impurities (such as slag, gas) to the casting surface, thereby significantly improve casting outer layer of the density and purity.

Centrifugal casting VS. Traditional sand casting: A Showdown of craftsmanship

Although the goal of both is to turn molten metal into solid parts, centrifugal casting and traditional sand casting have essential differences in methods and results.

1. Principle and Mold:

• Centrifugal casting: relying on centrifugal force to form, usually using metal molds, which can be rotated at high speed.

• Traditional sand casting: relying on gravity filling, using sand mold, disposable consumables.

2. Product Structure and Quality:

• Centrifugal casting: specializes in the production of axisometrically symmetric tubular and tubular parts. The castings have fine grain, dense structure and excellent mechanical properties, especially compressive and fatigue resistance. As the impurities are separated by centrifugal force, the product has fewer defects and high internal quality.

• Traditional sand casting: can produce extremely complex shaped parts, such as engine blocks, machine tool beds, etc. However, the structure of castings is relatively loose, prone to shrinkage, porosity and other defects, surface finish and dimensional accuracy are usually lower than centrifugal castings.

3. Material Utilization Rate and production efficiency

• Centrifugal casting: don't need to water the riser system, material utilization rate is extremely high, can reach more than 90%.The metal mold can be reused, the production efficiency is high, and it is easy to realize mechanization and automation production.

• Traditional sand casting: It requires a large gate and riser system for feeding, and the material utilization rate is relatively low (usually 50%-60%). Sand mould making time-consuming, laborious and for one-time use, long production period and low efficiency.

Analysis of the Advantages and Disadvantages of Centrifugal Casting

Advantages

• Outstanding mechanical properties: The castings have high density, good wear resistance and pressure resistance.

• High material utilization rate: Save metals and reduce costs.

• Excellent surface quality: precise dimensions and smooth surface.

• High production efficiency: Suitable for mass production of specific types of products.

• Bimetallic casting is possible: For instance, a layer of copper alloy can be centrifugally cast on the inner wall of a steel pipe to manufacture bimetallic composite rollers.

Disadvantage

• Significant shape limitations: Mainly suitable for rotary body parts, unable to produce complex structural components.

• High equipment investment: Centrifugal casting machines are more expensive than sand casting equipment.

• Unstable inner hole quality: The inner surface may contain impurities and the dimensions are not precise, usually requiring subsequent machining.

• High requirements for process control: Parameters such as rotational speed and pouring temperature need to be precisely controlled.

Main application fields

The unique advantages of centrifugal casting technology make it the preferred manufacturing process for the following key products:

• Pipeline category: Various cast pipes, such as centrifugal ductile iron pipes for water and gas transmission, are the most widely used fields.

• Cylinder liner type: Cylinder liners and piston rings of engines are required to have extremely high wear resistance.

• Roller type: Various rollers used in papermaking, metallurgy, and plastic machinery.

• Bearing rings: Rings for large rolling bearings.

• Military and aerospace: artillery barrel, rocket compartment and other high performance components.

In conclusion, the centrifugal casting is not to replace the traditional sand casting, but the powerful supplement for its formation.When choosing casting process, the enterprise should be based on the shape of the product, performance requirements and production batch make comprehensive judgment. For symmetrical rotary parts with large quantities and high- performance requirements, centrifugal casting is undoubtedly the "gold standard" that combines economy and outstanding performance. With the continuous development of the high-end equipment manufacturing industry, centrifugal casting technology is bound to have a broader application prospect.