Metal casting is a fabrication process that involves producing a casting by pouring liquid metal into a mold with a hollow cavity of a particular shape and then left to cool and solidify. Metal casting has been in existence for many years, making various castings like wind turbines, swords, cast chrome valves, etc. Today it’s one of the most varied methods used to make high-quality metal parts.
In this post, the whole process of metal casting is explained, including the types of metal casting in detail. Keep reading.
The Metal Casting Process Simplified
The main activities in the metal casting process involve heating metals to form molten ( liquid) metal, pouring it into a mold, waiting for it to cool, then removing the casting. There are many other stages involved in the metal casting process. They all depend on the types of metal forms and the procedure of making them.
The following are simple step-by-step explanations of the metal casting process;
Step 1: Making the Pattern
To commence the process, you require the fabrication of a pattern of a replication of the casting to make a mold. A pattern can be permanent or disposable. The materials used can be; wood, wax, or plastic.
Step 2: Making the Core
The core is a solid piece of material that is put inside the mold space to shape the interior geometry of the cast item. For example, to make an oval-like casting, you make an oval core.
Step 3: Making the Mold
There are different ways of making molds; permanent and sand molds. A permanent metal mold is made using a CNC machine, while a sand mold is made by applying a sand mixture on the outer surface of a pattern.
Step 4: Filling the Mold
In this step, the metal is heated until it melts. It’s then put into a mold either forcefully or by pouring. Pouring the molten involves applying the force of gravity, whereby, the molten is poured downwards into the mold. Forceful filling, on the other hand, uses high pressure to force the molten material into the mold.
Step 5: Removing the Part
Removing the part happens when the molten cools and solidifies in the mold. The removal process depends on the type of mold used. For disposable mold like sand, the sand is destroyed to reach the inside part, for permanent mold, you pull the two parts of the metal mold to remove the part, and the mold can be used again.
Step 6: Post-Processing
This is the final stage. It involves the final cleaning and removal of any parts of the mold that might have remained during the process of removal. After cleaning, the casting is now ready to use.
Metal casting has many advantages over other metalworking options, like CNC machining or forging, because it can produce huge and heavy machines. A cast chrome valves distributor and other heavy machine dealers can benefit from metal casting.
Types of Metal Casting
The following are the main types of metal casting:
Gravity casting depends on gravitational force to move the molten down into the mold. It, therefore, doesn’t require pressure to move the molten. Cast iron is the best material for gravitational casting because of its low thermal fatigue. It must be pre-heated before the molten is poured into it.
The molten is forced into the mold with high pressure. It’s common in mass production due to the high cost of creating dies. Die casting has magnificent finishes.
It is also known as lost wax casting. The pattern is formed by wax or from another expendable material. A refractory, ( investment) material is then poured around the pattern to make a mold.
Indeed, metal casting is a very crucial process in metal manufacturing industries. Learning about it and embracing it can boost the industry a great deal.