The die casting process is one of the manufacturing processes that converts molten/liquid metal into the intended final shape with the necessary structure and properties for the intended uses. The basic concept of the die casting process is that solid metal is melted, then transferred into a set of dies and solidified in the die cavity to form solid casting. There are basic six factors that are involved in all casting manufacturing processes.
- MOLD OR DIE MAKING
- METAL MELTING
- METAL INJECTION
- CASTING EJECTION
- FETTLING AND TRIMMING
- FINISHING PROCESSES
 A brief description of all the above is as follows:
Table of Contents
MOLD OR DIE MAKING
In the manufacturing process casting, a mold or die cavity/insert preparation is the first and most important step to produce the desired finished casting with the required shape and size. In Sand Casting Process, a new mold is prepared for each casting. In Die Casting Process, a permanent die cavity is used repeatedly to produce the same castings.
AÂ mold or die material must be carefully selected, so that it will not chemically react to the molten metal, can withstand to molten metal temperature, and is able to produce the desired shape that it contains.
METAL MELTING
There must be a suitable way to melt the cast alloys. The melting furnace/equipment must be able to provide the molten metal in sufficient volume, at an acceptable quality and reasonable cost, and at an adequate temperature.
After the metal melting and before the metal injection process, the metal purification or cleaning activity must be done by adding cleaning agents like fluxes, and chlorine tablets, and by metal de-gassing process especially performed in high-pressure die casting-HPDC, low-pressure die casting-LPDC, and gravity die casting-GDC.
METAL INJECTION
There must be a suitable way to pour the molten metal into the mold or die cavity. A plunger of the injection cylinder typically performs the metal injection process. The shot position and speed must be well controlled so that the air or gases present in the mold or die cavity can escape easily prior to filling the molten metal completely into the mold or die cavity.
CASTING INJECTION
The casting must be able to be removed easily from the mold. This is very important for die-casting processes that use permanent molds. Therefore, at the start of the design process, the designer must consider the important factors about how to eject the casting easily from the mold. The important factor that must be considered is – the geometry of the castings, the usage of cores and slides, the location or placement of the parting line and ejector pins, the depth of draw, and the draft angle.
FETTLING AND TRIMMING PROCESSES
After the casting ejection process, fettling and trimming operations or processes are performed to remove the extra material such as the runners, risers, gates, vents, overflows, etc. that is attached to the casting. The heat treatment process is also performed after the fettling/trimming operation as per the customer’s requirement or product application.
FINISHING PROCESSES
After the fettling and trimming operation, some finishing processes like grinding, buffing, and shot blasting operations are performed as per the customer’s requirement.
TYPES OF CASTING | MANUFACTURING PROCESS CASTING
The casting process is broadly classified into two categories:
- Ferrous Casting Process
- Non-Ferrous Casting Process
Ferrous Casting Process– Iron is the main constituent.
For example- Sand Casting, SGI Casting, and CI Casting, etc.
Non-Ferrous Casting Process – Iron is not the main constituent.
For Example- Aluminum Die Casting, Zinc, and Copper Die Casting.
The different Types of Casting processes listed below are used in manufacturing industries to produce products with desired shapes and sizes.
- High-pressure die casting-HPDC
- Low-pressure die casting-LPDC
- Gravity die casting-GDC
- Sand casting
- Investment casting
- Centrifugal casting
- Vacuum die casting
- Squeezing die-casting
- Lost Foam Casting
- Continual Casting
