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 meet 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.
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.
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 duration of injection time can be determined by the thermodynamic properties of the material, as well as the wall thickness of the casting. Greater wall thickness will require a longer injection time.
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. 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.
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.
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:
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 machines are used for Aluminum or Zinc alloys with high melting points.
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 gooseneck. 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 gooseneck and nozzle to the die cavity. Hot chamber die casting machines are primarily used for zinc, copper, lead and other low melting point alloys.
Description of component: BODY PUMP
Function: oil pumping station, air & gas filtration pump. Each component is required to meet a pressure test of over 5,000 psi without resulting in damage to the component assembly.
Die cast machined component weight: 2 lb. 14 oz.
Original component: machined sand casting
Rejection rate: 20%
Production rate: 5 – 7 pcs per shift
Die casting component:
Reject rate: <1%
Weight reduction: 5%
Production rate: 250 pcs per shift
Cost Reduction: over 50%.
Component description: Home security lockbox
Original component raw material: steel tubing
Manufacturing processes: bending, welding, machining, painting. The original manufacturing process is virtually a custom made-to-fit component.
Die casting component raw material: zinc.
The die casting process virtually eliminates the variability of both critical and functional features of the component. The reduction in cost and lead time is dramatic.
Cost Reduction is over 50%.
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
- Die Casting Aluminum - Aluminum alloys have been proven ideal for a wide range of products because of the unique combination of qualities they possess lightweight, 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.