Die Casting Manufacturing

Die casting is a versatile process that produces engineered parts through a forced high-pressure method of forcing molten metal into reusable steel molds, or dies. Die casting can be produced in nearly every conceivable size and shape. It provides the freedom to design intricate configurations that meets the functional requirement of the component. The die casting process produces castings with very close tolerances, often eliminating the need for finished machining operations. Depending on your application, there are many different types of die casting processes that can be achieved.

Contact us for more information regarding our die casting advantages and types of die casting processes, or call us at 510-523-2541 and we will be happy to assist you with any questions that you may have.

Process Cycles & Types of Die Casting

The basic die casting process consists of injecting molten metal under high pressure into a steel mold called a die. A complete die casting cycle can vary from less than a few seconds for small components to 2-3 minutes for a casting of over 30 lbs, making die casting the fastest technique available for producing precise non-ferrous metal parts. The following processes are routinely used to create custom die casting applications.

Clamping

The first step in the die casting process involves the preparation and clamping of two die halves. Once cleaned and properly prepared, the two clean die halves are lubricated to prevent sticking and then closed, securely clamping them together. During this phase, force must be applied to the die to keep it secure while the metal is injected.

Injection

Once transferred from either a hot or cold chamber machine, the molten metal is injected into the die through a high pressure process. These pressures can range from 1,000 to 20,000 psi. The total injection time  required for a project will depend upon the length of time required to fill all the cavities and channels within the die. The correct deration of injection time can be determined by the thermodynamic properties of the material, as well as the wall thickness of the casting. A greater wall thickness will require a longer injection time.

Cooling

The cooling process begins the moment the molten metal enters the die cavity. Once the entire cavity of the mold is filled and the molten metal solidifies, the final shape of the casting is formed. It is important that the die not be opened until it has completely cooled. This ensures that the casting is completely solidified. A greater wall thickness will require a longer cooling time. Additionally, the geometric complexity of the die also requires a longer cooling time due to the additional resistance to the flow of heat.

Ejection

Once the proper amount of cooling time has elapsed, the die halves can be opened and ejected from the die cavity. Once the casting is ejected, the die can be clamped shut for the next injection.

Trimming

Excess material and flash must be trimmed from the channels of the die due to solidification during the casting process. This is accomplished either manually or through the assistance of a saw, or trimming press. The scrap material that results from this trimming is either discarded or can be reused in the die casting process.

Die Casting Applications

Depending on your specific parameters, one type of die casting method may be favorable over another. At SKS Die Casting we can perform numerous types of die casting, ensuring that your part is suitable for the environment in which it will perform. We are capable of the following types of die casting:

Cold Chamber Die Casting

Within this die casting process, molten metal is poured into the cold chamber or cylindrical sleeve by ladle. A hydraulically operated plunger seals the cold chamber port and forces the metal into the die cavity at high pressure. Cold chamber die casting machine are used for Aluminum or Zinc alloys with high melting points.

Hot Chamber Die Casting

The injection mechanism of a hot chamber machine is immersed in a molten metal bath of a metal holding furnace. The furnace is attached to the machine by a metal feeding system called the goose neck. As the injection cylinder plunger rises, a port in the injection cylinder opens allowing the molten metal to fill the cylinder. As the plunger moves downward, it seals the port and forces metal to fill the cavity through the goose neck and nozzle to the die cavity. Hot chamber die casting machine are primary used for zinc, copper, lead and other low melting point alloys.

Die Casting Advantages

Die casting allows for the creation of parts with complex shapes and intricate designs at a price point that doesn’t break the bank. Some of the greatest benefits associated with die casting, include:

• Advanced production speed
• Accurate dimensional stability
• Tight tolerances
• Variable wall thicknesses
• Fast production times
• Reduction in scrap
• Extended tool life

Types of Die Casting Material

We can perform numerous die casting methods utilizing both aluminum and zinc alloys. Some of the advantages associated with both of these materials, include:

• Die Casting Aluminum - Aluminum alloys have been proven ideal for a wide range of products because of the unique combination of qualities they possess light weight, good corrosion resistance, high tensile strength, high dimensional stability, high thermal and electrical conductivity. Alloy 380.0 is the most commonly used Aluminum alloy for die casting and has been found to meet customers' various needs. Importantly, SKS can also cast Aluminum Alloys 360, 390 and 413.
• Die Casting Zinc – The mechanical properties of zinc alloy die castings at normal temperatures are superior to sand castings of grey iron, brass, and aluminum, particularly in toughness and impact strength. They are much stronger, tougher, and more dimensionally stable than injection molded plastics. The reduced cost and improved properties have made it an ideal replacement for iron, copper, aluminum alloys or plastics parts.

Contact SKS Die Casting for our Custom Die Applications Today

Contact us for more information regarding our die casting options and die casting materials, or request a quote for an in-depth price analysis today.