Custom Die Castings
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Brass Die Casting Water Meter
Pressure Die Casting Brass Machining Parts
Die Cast Water Fountain Spray Unit
For high-volume production runs, die-casting is an effective manufacturing process. At Deeco Metals, we use die casting to manufacture top-quality parts for a wide range of industries. Some examples of the parts we make include:
- Light housings
- Electrical cases and housings
Advantages of Die Casting
There are a number of reasons to choose die-casting for your complex metal parts. Die-casting provides parts which are durable, dimensionally stable and have the feel and appearance of quality. Die-casting also produces complex shapes within closer tolerances than many other mass casting production processes. Die-castings are produced at high rates of production. In some cases very little or no machining is required. Die casting dies can be made with multiple cavities and can produce thousands of identical castings within specified tolerances before refurbishment or new tooling is required.
Corrosion resistance of die-casting alloys rate from good to high. Die castings combine many functions in one complex shaped part. Because die castings do not consist of separate or welded parts that are fastened together, their strength comes from the material, not threads, welds, or other joining methods.
Other benefits of die-casting include:
- Die castings can be produced with surfaces simulating a wide variety of textures.
- Die castings can be produced with thinner walls than those obtainable by other casting methods and much stronger than plastic injection moldings with the same dimensions.
- Die castings provide integral fastening areas, such as bosses and studs, which can result in assembly savings.
- Holes in die castings can be cored, and made to tap drill sizes. External threads on parts can often be die cast.
- Metal and some non-metal inserts can be cast in place.
How Die Casting Works
Die-casting involves the injection of liquid metal into a multipart die under high pressure. Pneumatically actuated dies make the process almost completely automated. Die-casting is best known for its ability to produce high-quality products at very low unit costs but requires high volumes of parts. Very high production rates (large quantities) offset the cost of the complex heat-resisting metal tooling required; and with low labor costs, overall casting costs are quite attractive.
Materials for Die Casting
The process can be used with several copper alloys, including:
- Yellow brass
- manganese bronzes
- C86200 and C86500
- Silicon brass
- The special die casting alloys C99700 and C99750
These alloys can be die cast because they exhibit narrow freezing ranges and high beta phase contents. Rapid freezing is needed to complement the process's fast cycle times. Rapid freezing also avoids the hot shortness associated with prolonged mushy solidification. Beta phase contributes the hot ductility needed to avoid hot cracking as the casting shrinks in the unyielding metal mold.
Extremely rapid cooling rates (dies are normally water cooled) results in very fine grain sizes and good mechanical properties. Leaded alloys C85800 and C99750 can yield castings that are pressure tight, although lead is incorporated in these alloys more for its favorable effect on machinability than for its ability to seal porosity.
Die-casting: Making Use of High-Quality Materials
Die-casting typically makes use of non-ferrous alloys which offer numerous benefits. The four most common alloys that are die cast are shown below, along with brief descriptions of their properties.
- Low density
- Good corrosion resistance
- High thermal and electrical conductivity
- High dimensional stability
- Relatively easy to cast
- Requires a use of a cold chamber machine
- High strength and toughness
- High corrosion and wear resistance
- High dimensional stability
- Highest cost
- Low die life due to high melting temperature
- Requires use of a cold chamber machine
- Very low density
- High strength-to-weight ratio
- Excellent machinability after casting
- Use of both hot and cold chamber machines
- High density
- High ductility
- Good impact training
- Excellent surface smoothness allowing for painting or plating
- Requires such coating due to susceptibility to corrosion
- Easiest to cast
- Can form very thin walls
- Long die life due to low melting point
Finishes for Die-Cast Parts
All alloys that are die cast can be left “as cast.” Additional finishing options include:
- Shot blasting
- Vibratory finishing
- Powder coating
- Acid etching
- Solution color Patinas
Zinc castings can be easily plated or finished with a minimum of surface preparation. Other metals may require additional surface preparation, as cast die-cast products are smoother than most other forms of castings.
Machinery for Die Casting
There are two main types of machines that die casting that we use at Deeco Metals: hot chamber machines (used for alloys with low melting temperatures, such as zinc) and cold chamber machines (used for alloys with high melting temperatures, such as aluminum and brass). However, in both machines, after the molten metal is injected into the dies, it rapidly cools and solidifies into the final part called the casting.
The castings that are created in this process can vary greatly in size and weight, ranging from a couple ounces to 100 pounds.