Have you ever wondered how some of your favorite tools and pieces of equipment are made? What about your everyday items? Ever imagined how they came about?
Well, the general answer is Casting. Casting is one of the oldest and crudest forms of technology. Many products we see around us today are formed through this method. It is much safe to say that casting is the bedrock of the industrial sector. But again, what exactly is casting? Are all these tools around us today made from the same type of casting?
What Is Casting?
When products or tools have complex shapes, hollows, irregular curved surfaces, and internal cavities, making it more difficult to machine, the casting process is applied to make such tools.
The casting process involves pouring liquified material like molten metal into a mold cavity with the shape and size you desire to produce. This molten metal is then allowed to cool and solidify in the designed mold. After the cooling and solidification phase, the cast will be removed from the mold and moved to the next production stage, finishing.
Casting is one of the least expensive ways to manufacture a piece of equipment or create machinery parts. Products made from casting can be found in different areas, including the construction sector, automotive sector, rail, aerospace, etc.
What Are The Types Of Casting?
The major types of casting include die casting, sand casting, plaster casting, investment casting, and permanent mold casting. Each of these types of castings has its pros and cons. To find the most suitable type of casting to be applied in creating any piece of machinery, you need to understand these types and their advantages and disadvantages.
Die casting is done by continuously introducing a high-pressure molten metal into a mold cavity at high speed until the workpiece solidifies. The rapid flow of the molten material to the cavity prevents any part from solidifying before the full casting is done. The reusable mold is always coated. This coating with lubricant ensures easy ejection after the casting is done and also helps regulate the die’s temperature.
Die casting is very expensive and takes time to fabricate. Materials like tin, aluminum, zinc, and copper are mostly used here. Die casting can be classified into;
Hot chamber die-casting
Cold-chamber die casting
This is the oldest and most popular type of casting known to humankind. Sand casting depends heavily on silica-based materials (synthetic or naturally bound sand). The casting sand mostly consists of grains (spherical and finely ground grains) packed together to form a smooth mold surface.
Generally, the sand casting process involves a furnace, pattern, and sand mold. While it uses a sand mold, iron, steel, and many other non-ferrous alloy castings can be obtained through this process.
Similar to sand casting, but in place of sand, plaster casting uses a mixture of gypsum, strengthening compound, and water to c reate a mold. An anti-adhesive compound is applied to the plater pattern to prevent it from getting stuck with the mold.
Although it may be more expensive than the sand casting process as steady replacements of the plaster molding material are needed, it delivers a more efficient result.
Investment casting involves the use of wax patterns and refractory material. Here, a wax is directly injected into a mold. Then the surface will be covered with refractory materials. The hardened patterns in the mold shell are then baked in the oven to remove the wax.
Investment casting is mostly applied in the production of turbine engine blades.
In recent years, there have been more and more tech advances in casting, leading to more types of casting with specialization and improved product design. If we had to go through every type of casting, then we would be here forever. Casting is very much popular across different sectors that deal with product manufacturing.