High-Pressure Die Casting – Key Applications and Advantages
High-pressure die casting is one of the most efficient methods of producing metal castings, primarily in aluminum. It allows accurate castings with thin walls and a smooth surface to be produced in large series. Below, we describe where die castings are used, and what their advantages and limitations are.
What is high-pressure die casting?
In high-pressure die casting, liquid metal is forced at high speed and under high pressure into a steel die, and once the cavity is filled, the pressure is held until the casting solidifies. Aluminum is cast on cold-chamber machines, in which the metal is ladled in portions into the shot sleeve. The cycle usually lasts from a dozen or so seconds to 1–2 minutes, depending on casting size, so the process is efficient in series production and the cost per casting is low.
Main applications of high-pressure die casting
Automotive industry
Aluminum die castings include transmission and clutch housings, pump bodies, brackets, electronics enclosures and cooling system components. They make it possible to reduce vehicle weight while maintaining part stiffness.
Household Appliances and Power Tools
In household appliances and power tools, die castings are used to make bodies, motor and gearbox housings, and covers – parts produced in large series where repeatable dimensions and a good surface finish matter.
Electronics and telecommunications
Equipment housings, heat sinks and structural components are die cast from aluminum. Aluminum conducts heat well, and the thin fins of heat sinks can be produced directly in the casting.
Aerospace industry
In aerospace, die castings are used mainly for non-structural parts – housings, covers and brackets. Load-bearing parts, which require full strength and heat treatment, are more often made by other methods.
Medical industry
In medical equipment, aluminum die castings are mainly housings for diagnostic apparatus and devices, as well as structural components of equipment. Repeatable dimensions and careful surface finishing matter here.
Advantages of high-pressure die casting
High precision and surface quality
Die castings accurately reproduce the shape of the die, and their surface is smooth. Many surfaces require no machining – usually only functional surfaces such as holes, threads and mating faces are machined. Dimensional accuracy is specified by a tolerance class, e.g. according to PN-EN ISO 8062-3.
Production speed
A short cycle and automation make it possible to produce a large number of castings in a short time. This is why high-pressure die casting is the primary method in high-volume production.
Ability to produce complex shapes
Metal forced in under pressure fills thin walls, ribs and fine details that are difficult to achieve with other casting methods. The functions of several parts can be combined in a single casting, which shortens assembly.
Material Savings
Castings are close to the shape of the finished part, so machining allowances are small. Gating systems and overflows can be remelted.
Durability and strength
Rapid solidification in a steel die produces a fine-grained structure, especially in the near-surface layer, so die castings have good strength even in the as-cast condition. Typical alloys are EN AC-46200, 46500 and 47100.
Limitations of High-Pressure Die Casting
- Mold cost – a tool steel die is expensive, so the process pays off for larger series.
- Porosity – gases trapped in the casting usually rule out conventional heat treatment and make welding more difficult.
- Casting Size – limited by the machine's clamping force and the capacity of the shot sleeve.
When high-pressure die casting pays off, and when it is better to choose a permanent mold or a sand mold, is described in the article aluminum high-pressure die casting – when it pays off.
Summary
High-pressure die casting combines precision, a smooth surface and a short production cycle, which is why aluminum die castings are used in automotive, household appliances, electronics, aerospace and medicine. In our foundry, we die cast aluminum alloys in series of up to 100,000 pcs per year. We design dies in CAD/CAM with melt flow simulation and make them in our own tooling department, while the castings are machined and coated in the same plant.
See also: how high-pressure die casting of aluminum works i die casting foundries – types and ordering castings.
Planning a production run of die castings? Send a drawing or 3D model to odlewnia@adjatech.pl or call: +48 61 662 43 37 (Mon–Fri 8:30 a.m.–4:30 p.m.).
Scope of services: foundry production capabilities.