Die casting is a metal casting process characterized by the use of a mold cavity to apply high pressure to the molten metal while it is in the process of being formed. Molds are typically machined from high-strength alloys, some of which are similar in appearance to those used in injection molding processes. The majority of die castings are made of non-ferrous metals such as zinc, copper, aluminum, magnesium, lead, tin, and lead-tin alloys, as well as alloys of these metals and others. Cold chamber die casting machines or hot chamber die casting machines, depending on the type of die casting required, are both viable options.

Throughout this post, the primary focus will be on the die casting manufacturing process. In order to provide you with a thorough understanding of the die casting process, we will introduce you to the two most basic types of die casting machines, as well as the detailed manufacturing procedures that are used in the process. After reading this post, you will be able to significantly improve the efficiency of your manufacturing process.

1. There are two different types of die casting machines.

It is possible to categorize die casting machines into two types: hot chamber zinc alloy die casting factory machines and cold chamber China die casting manufacturer machines. There is a significant difference in the amount of force they can withstand. The typical range of pressure is 400 to 4,000 tons per square inch.

1.1 Die casting machines with a hot chamber

Hot chamber die casting, also known as gooseneck die casting, is a type of die casting that relies on a pool of molten metal to fill the die while it is under pressure. The machine's piston is in a retracted state at the start of the cycle, allowing molten metal to fill the "gooseneck" at the start of the cycle. The metal is squeezed and filled into the mold by a piston powered by pneumatic or hydraulic pressure. In addition to having quick cycle times (approximately 15 cycles per minute), this system also has the capability to melt metal.

The disadvantages, on the other hand, include the inability to die-cast a metal with a high melting point, as well as the die-casting of aluminum, because aluminum will pull the iron out of the molten pool during the die-casting procedure. As a result, hot chamber die casting machines are frequently used for the production of zinc, tin, and lead alloys. Furthermore, hot chamber die casting is more commonly used for small castings rather than large castings, and it is less expensive.

1.2 Die casting machines with a cold chamber

Cold die casting can be used for die casting metals that cannot be used in hot chamber die casting processes, such as aluminum, magnesium, copper, and zinc alloys with a high aluminum content. Cold die casting can also be used for die casting metals that cannot be used in hot chamber die casting processes, such as titanium. In this process, the metal must first be melted in a separate crucible before it can be used. The molten metal is then transferred to an unheated injection chamber or nozzle, where it cools and solidifies. Hydraulic or mechanical pressure is used to force these metals into the mold.

It is necessary to transfer molten metal into the cold chamber, which results in a lengthy cycle time. This is the most significant disadvantage of this process. Cold chamber die casting machines are also available in a variety of configurations, including vertical and horizontal. In general, vertical die casting machines are small machines, whereas horizontal die casting machines are available in a variety of sizes and configurations.

Die casting manufacturing processes are described in detail.

The high pressure die casting process is comprised of four steps, which are mold preparation, filling, injection, and shake out. These steps serve as the foundation for various improved die casting processes, which are discussed further below.

2.1 Preparation of the Environment

It is necessary to spray lubricant into the cavity during the preparation process. In addition to assisting in the control of the mold's temperature, the lubricant can aid in the removal of the casting, after which the mold can be closed.

2.2 Filling in the blanks

The molten metal is injected into the mold at a high pressure ranging from approximately 10 to 175 MPa, depending on the size of the mold. When the molten metal has been completely poured into the mold, the pressure is maintained until the casting has solidified.

Injection (2.3)

The dies are then opened, and the shot (which differs from castings in that there can be multiple cavities in a die, resulting in multiple castings per shot) is ejected by the ejector pins as the dies close. When using high-pressure injection, the mold is completely filled in a short period of time, allowing the molten metal to fill the entire mold before any individual part solidifies. Surface discontinuities can be avoided even in thin-walled sections that are difficult to fill if this method is used. The majority of die castings can be used to complete structures that would otherwise be impossible to complete by casting, such as drilling and polishing.