Summary
Die casting is a manufacturing process that forces molten metal under high pressure into a mold cavity. In its working, the mold cavity is created using two hardened tool steel dies which have been machined into the object’s shape.
There are different types of die-casting with varying principles of working: hot chamber die-casting, cold chamber die-casting, high-pressure die-casting, and low-pressure die-casting.
In high-pressure die casting, the working process involves crucial steps, including preparing the mold, injection, cavity ejection, and shakeout. Learn about the various types of die-casting processes here!
Now, let’s go deep to explain the working principle of die-casting!
Contents
Working Principle of Die-Casting
Die casting is carried out firstly by spraying a mold cavity with a release agent to ensure easy and successful removal of the casting. molten metal is poured into a casting chamber, which is connected to the mold cavity. piston here plays an important role by pressing liquid metal into a part call a channel.
Die casting with series of mold contains series of channels connected to them. At this point, casting solidifies under high pressure and removes. This principle is to carry out the same way on hot and cold chamber types of die casting.
- Spraying mold with releasing agent
- Filling liquid alloys quickly into a chamber
- Pushing alloys to mold cavity under high pressure
- Allowing casting to solidify before removing from the machine.
In high pressure die casting, molten metal such as steel, zinc, copper, aluminum, lead, magnesium are injected into a three dimensional mold carrying the shape of the casting. The metal is heated to extreme temperature until changes to molten state, which is then forced into a mold’s cavity to take its shape when cooled. The four steps in die-casting working process include:
Preparing the Mold
The first step of this process is to prepare the mold, which is creating the die that serve as the replica of the object. There is a special kind of lubricant applied to the inner walls of the mold to control its temperature as its forms a film between the molten metal and the mold. This ease the removal of the casting once it’s cooled.
Injection
After the mold preparation, the molten metal is injected into it at high pressure. The mold bust are shut tight and sealed as it may reject the high pressurized molten metal if not close tightly.
The pressure at which the molten metal is pushed ranges from 1,500 to 25,000 PSI (Pounds per Square Inch), although it depends on their use cases. This pressure is contained by the mould as the molten metal is allowed to cool.
Cavity Ejection
At this point, the metal object solidifies, and needs to be ejected. Most die casting mold features an ejector pin that automatically release the cavity. This ejector pin will work well if the formed cavity is at solid state.
Shakeout
This is the final step of die-casting, which is achieved by separating scrap and waste metal that forms during the manufacturing process. High pressure type are known to produce excessive amount of scrap metal which is why this stage is neccessary. Also, some molten metal stick to the mold and they must be remove so that they can be reuse.
Learn about investment casting here!
That’s all for this article, where the working of die casting is being explained. I hope you got a lot from the reading, if so, kindly share with other students. Thanks for reading, see you next time!
Leave a Reply