Are you looking for specialist in custom diecasting and aluminium extrusions? Working from drawings or samples provided, our expert diecasting and aluminium alloy extrusion designers and toolmakers will deliver aluminium extrusions from China with high tolerance and lowest possible cost. Working closely with you we will select suitable extrusion or diecasting process and design the tooling to suite your application. Alloy selection will be as per specification or advised based on your requirements. We offer the highest quality Aluminum diecasting and custom extrusions China can provide, keeping the cost low and delivering high quality part.
Aluminum die casting explained
Diecasting is a process of injection of Aluminum, Zinc and Copper alloy under pressure, which can produce parts in high volume at low costs. There are two processes of Aluminum alloy diecasting: hot chamber and cold chamber. Diecasting machines are typically rated in amount of pressure they can exert on the die. Regardless of their size, the only fundamental difference in diecasting machines is the method used to inject molten zinc alloy into a die. A complete cycle can vary from one second for small components to minutes for a casting of large part, making custom diecasting the fastest technique available for producing precise Aluminum alloy parts. A top custom aluminum extrusion manufacturer in China offer manufacturing of part and components at a fraction of the cost in other countries. That’s what we provide, plus other services you’ll find from a top of the line Aluminum diecasting company.
Advantages of Aluminum die casting
- Economical process offering a wide range of shapes of diecasted components than any other manufacturing technique.
- Parts have long service life and can be die casted to complement the visual appeal of the final product
- Complex shapes and high dimensional accuracy and stability than other mass production processes. Some machining may be required depending on the design
- Parts are stronger than plastic injection moldings having the same dimensions. Thin wall castings are stronger and lighter
- Diecasted parts can be manufactured with smooth or textured surfaces, and they can be easily finished with a minimum of surface preparation.
- Can provide integral fastening elements as part of the design. For many parts, post-machining can be totally eliminated, or very light machining may be required to bring dimensions to size
Cold chamber hot chamber process explained:
In a cold chamber process, the molten metal is directed into the cold chamber for each shot. There is very little time exposure of the Aluminum alloy to the plunger walls or the plunger. This is particularly useful for metals such as Aluminum and Copper (and its alloys).
In a hot chamber process the die is connected to the die cavity and immersed permanently in the molten metal. The inlet port of the pressurizing cylinder is uncovered as the plunger moves to the open (unpressurized) position. This allows a new charge of molten metal to fill the cavity and thus can fill the cavity faster than the cold chamber process. The hot chamber process is used for metals of low melting point and high fluidity such as tin, zinc, and lead that tend not to alloy easily with steel at their melt temperatures.
Custom Aluminum Alloy Extrusions
Aluminium Extrusion is the process by which long straight and shaped parts can be produced. The cross-sections that can be produced vary from solid round, rectangular, to L shapes, T shapes. Tubes and many other different types. Extrusion is done by squeezing metal in a closed cavity through a tool, known as a die using either a mechanical or hydraulic press.
Extrusion produces shear as well as compressive forces in the stock. No tensile is produced, this makes high deformation of the Aluminum extrusion possible without tearing the metal. The cavity in which the raw material is contained is lined with a wear resistant material. This can withstand the high radial loads that are created when the material is pushed thru the die. Extrusions, often minimize the need for secondary machining, but are not of the same dimensional accuracy or surface finish as CNC machined parts.
Cold Aluminum Extrusion: Cold extrusion is the process done at room temperature or slightly higher temperatures. This process can be used with Aluminum and zinc alloy and subject to designing a extrusion die that can withstand the stresses created by extrusion. Parts that are cold extruded are collapsible tubes, Aluminum cans, cylinders, gear blanks. The main advantages of cold extrusion are:
- Material does not oxidize
- Extrusions maintain excellent mechanical properties as long as the temperatures during the extrusion are below the re-crystallization threshold
- Attractive surface finish when proper lubricants are applied during the process
Hot Aluminum Extrusion: Hot extrusion is done at high temperatures, approximately 50 to 75 % of the melting point of the alloy. The pressures can range from 35-700 MPa (5076 - 101,526 psi). Due to the high temperatures and pressures and its detrimental effect on the dieset life as well as other components, good lubrication is essential. Graphite applied at lower temperatures, at higher temperatures glass powder is used.
Parts produced by extrusions are hollow parts, commonly used in automotive and consumer appliances, window frame members, railings, aircraft structural parts.
Choosing the Proper Alloy for diecasting or Aluminum Extrusion Process
Each of the metal alloys available for aluminum diecasting offer particular advantages.
Zinc - The easiest alloy to cast, it offers high ductility, high impact strength and is easily plated. Zinc is economical for small parts, has a low melting point and promotes long die life.
Aluminum - This alloy is lightweight, while possessing high dimensional stability for complex shapes and thin walls. Aluminum has good corrosion resistance and mechanical properties, high thermal and electrical conductivity, as well as strength at high temperatures.
Magnesium - The easiest alloy to machine, magnesium has an excellent strength-to-weight ratio and is the lightest alloy commonly die cast.
Copper - This alloy possesses high hardness, high corrosion resistance and the highest mechanical properties of alloys cast. It offers excellent wear resistance and dimensional stability, with strength approaching that of steel parts.
Lead and Tin - These alloys offer high density and are capable of producing parts with extremely close dimensions. They are also used for special forms of corrosion resistance.
Diecasting is one of the fastest and most cost-effective methods for producing a wide range of components. However, to achieve maximum benefits from this process, it is critical that designers collaborate with the die caster maker at an early stage of the product design and development. Consulting with the die caster during the design phase will help to prevent the issues affecting tooling and production, while identifying the various trade-offs that could affect overall costs.
For instance, parts having external undercuts or projections often require dies with sliding cores. That increase the cost of the tooling, but may result in reduced metal use, uniform casting wall thickness or other advantages. These savings may offset the cost of tooling, depending upon the production quantities, providing overall economies.