Aluminum High Pressure Die Casting: The Ultimate FAQ Guide

Before choosing the aluminum high-pressure die casting process, read this guide.

It has all information you need about the aluminum high-pressure die casting process.

So, keep reading to learn more.

What Is Aluminum High-Pressure Die Casting?

Aluminum high pressure dies casting is a technique where you will force molten aluminum metal under intense pressure within a sealed mold cavity.

The molten aluminum is held within the mold via powerful compressive pressure power until it solidifies.

After the aluminum solidifies, you will release and open the die to remove the solid aluminum metal.

Once you remove the metal, you will reseal the mold cavity for the next aluminum cycle.

A High Pressure Die Casting Machine

A High-Pressure Die Casting Machine

What Makes Aluminum Suitable For High-Pressure Die Casting?

Here are some traits of aluminum alloy that makes them suitable for high-pressure die casting:

  • It can withstand high operating temperature levels
  • Lightweight
  • Suitable finishing traits
  • High corrosion resistance
  • Fully recyclable
  • High electrical conductivity
  • Suitable strength and hardness levels
  • Excellent thermal conductivity
  • Suitable shielding properties from EMI and RFI
  • Good strength-to-weight ratio
  • Suitable heat dissipation properties

What Are The Advantages Of Aluminum High-Pressure Die Casting?

Some of the benefits include the following:

  • It allows you to make large quantities of complex aluminum parts
  • Aluminum high pressure die casting has extremely short casting cycles since molten aluminum solidifies in seconds
  • The process is cost-effective especially when you are producing aluminum products in large amounts
  • Also, the process will create aluminum products with very smooth surfaces
  • It allows you to cast-aluminum products with thin walls and also lightweight
  • The process can make thousands to millions of aluminum products before needing replacement
  • It allows you to produce identical aluminum components that are identical
  • Enables you to achieve close tolerances

Aluminum High Pressure Die Casting Produces Smooth Surfaces

Figure 2-  Aluminum High Pressure Die Casting Produces Smooth Surfaces

What Are The Disadvantages Of Using Aluminum High Pressure Die Casting?

Some of the disadvantages include:

  • Aluminum high pressure die casting needs complex and costly machinery
  • It needs a high initial capital investment for setup
  • Compared to gravity die casting, it is relatively inflexible
  • Not suitable for individual or limited production processes
  • The product is porous with entrapped gasses meaning you cannot heat treat the aluminum die casting as surface blisters may form

How Do Hot Chamber And Cold Chamber Aluminum High-Pressure Die Casting Compare?

Here is how these two processes compare:

Hot Chamber System

This method is suitable if the alloy will not affect and erode the metal plungers and pot cylinders.

Here, you will immerse the injection unit in molten aluminum metal from blast furnaces.

As the piston pumps, it will force the molten aluminum into the die via nozzles.

A Hot Chamber System

Figure 3- amber System

Cold Chamber System

This process is suitable for use with aluminum since it melts at a high-temperature level.

Molten aluminum metal is in a separate holding pot where you will ladle and not pump it for casting purposes.

The two injection systems you can use in this setup include vertical and horizontal injections.

 A Cold Chamber Process

A Cold Chamber Process

What Processes Will You Undertake When Performing Aluminum High-Pressure Die Casting?

Aluminum high-pressure die casting entails injecting molten aluminum metal within a three-dimensional mold.

Once you heat the aluminum metal until it reaches a molten state, you will force it into the cavity of a mold to take its shape.

There are several ways for you to perform aluminum high-pressure die casting processes.

Besides, they all consist of these four main phases:

Mold Preparation

The first step you will take when performing aluminum high-pressure die casting is preparing the mold.

Here, the manufacturer will apply a lubricant to the inner walls of the mold.

This is vital since lubricants regulate the temperature of the mold and create a film between the molten aluminum metal and the mold.

The effect of this film is to allow you to easily remove the aluminum cast.


Once you prepare the mold, you will inject it with molten aluminum metal.

Besides, ensure you completely close and seal the mold during this phase otherwise it will not work well with the molten metal at high pressures.

Depending on the application, you may inject the molten aluminum metal at pressure levels between 1500 and 25000 PSI.

The mold will maintain this pressure level until the molten aluminum metal completely cools and solidifies.

Ejection Of Cavity

Afterward, you will remove the new cavity from the mold.

The mold contains ejector pins that you will engage to release the cavity.

Besides, the cavity must be in solid form for the ejection to happen.

If the aluminum metal is semi-solid, you need to wait for it to completely cool down before ejecting it from the cavity mold.


The final step in aluminum high-pressure die casting is the shakeout phase.

Here, you will remove any existing scrap metals from the newly created aluminum cavity.

Besides, it is common for aluminum high-pressure die casting to generate surplus scrap metal.

This means not all of the molten aluminum metal will be used to make the aluminum casting.

Some metal will stick to the insides of the mold, therefore, requiring you to eliminate them all before reusing it for the next cycle.

Is It Important To Maintain Uniform Wall Thickness In Aluminum High-Pressure Die Casting?

This is because you will make sure you achieve van unimpeded aluminum metal flow and enhance the solidification process.

If the final product needs thickness variation, adjust the process gradually to inhibit sharp edges from forming.

Achieving the suitable aluminum wall thickness can be a delicate process.

Thinner walls can lower material costs and make the final product lightweight.

However, it may diminish the strength and structural integrity of the final product.

No matter the thickness level you want to attain, it is important to maintain consistency in the whole component or part.

What Are Some Aluminum Alloys You Can Use When Performing Aluminum High Pressure Die Casting?

Aluminum alloys vary considerably.

The type of alloy you select means you can have characteristic variations in terms of:

  • Melting point
  • Electrical conductivity
  • Weight
  • Fatigue strength, etc.

Here are some common aluminum materials that you can use in the aluminum high pressure die casting process:

  • A380

This version is affordable and possesses high mechanical and thermal features, pressure tightness, and fluidity.

A380 Aluminum Alloy

A380 Aluminum Alloy

  • A383 or ADC12

This version has more resistance against corrosion, is easy to cast, and has suitable dimensional stability.

  • A413

This version is suitable for making hydraulic cylinders and other usages needing high-pressure tightness.

A413 Aluminum Die Cast

A413 Aluminum Die-Cast

Other alloys you can use include:

  • A360 which has excellent fluidity and pressure tightness
  • 413 which is common for die casting parts
  • K-alloy that is suitable for protecting parts against extreme operating conditions
  • B390 that has suitable wear resistance and high hardness

What Should You Look Out For When Selecting The Suitable Aluminum Alloy For Aluminum High-Pressure Die Casting?

Some factors you should look out for include the following:

  • The function and use of the finished product

Depending on the alloy you select, you may have high strength, corrosion resistance, etc.

  • Production volume

With good maintenance practices, high-pressure aluminum dies casting can last up to 100000 cycles.

What Are Some Applications Of Aluminum High-Pressure Die Casting?

With aluminum high-pressure die casting, you can make the following items:

  • Engine blocks
  • Ultrasound units
  • Automotive components
  • Heavy-duty fasteners
  • Heart monitors
  • Lawnmowers
  • Aerospace parts
  • Hand tools

Is There A Difference Between Aluminum High Pressure And Aluminum Low-Pressure Die Casting?

Aluminum high-pressure die casting happens when you inject or force the molten aluminum metal into a mold or a die.

Besides, you will horizontally inject the molten aluminum metal.

Also, aluminum high-pressure die casting can operate in both a cold chamber and hot chamber die casting.

Some of the advantages of aluminum high-pressure die casting include the following:

  • Operates effectively with large aluminum alloy parts
  • It has shorter casting cycles making the production process quick
  • The process leaves behind a smooth surface finish
  • It is affordable when conducting high-production runs
  • Suitable for making thin-walled configurations

Aluminum low-pressure die casting happens when you slowly fill molten aluminum metal in a die cavity through a tube on a holding surface.

Besides, in aluminum low-pressure die casting, you will fill the mold in a vertical orientation.

Some of the benefits of aluminum low-pressure die casting include the following:

  • It is cost-effective when dealing with small production processes
  • Also, it is precise and provides high dimensional accuracy
  • Suitable for automation
  • High strength values
  • It is suitable for designs that possess substantial wall thickness
  • Ideal for complicated designs and geometries

What It The Assembly Process In Aluminum High-Pressure Die Casting?

The assembly process for aluminum high-pressure die casting ranges from complex to simple techniques.

To complete complex assembly processes, you will require several steps.

When you need to assemble complex pieces, you will implement the following special methods:

  • Welding
  • Fastening
  • Threading
  • Coring holes
  • Injected metal assembly

Ensure you list the correct assembly process when planning the aluminum high-pressure die casting process.

This will affect the whole product design.

What Is Machining Allowance In Aluminum High-Pressure Die Casting?

Machining allowance is the total amount of stock that the material fabricators can eliminate from the final aluminum die-cast component.

It specifically references the allowance you need to remove inclusions on the aluminum die casting skin.

Besides, it will also define the impact of the surface roughness of the die-cast.

One of the important considerations when performing aluminum high pressure die casting process is to ensure the following:

  • That you achieve optimum mechanical characteristics, and
  • Attain optimum density close to the surface of the aluminum die-cast

When the allowance is insufficient, it may fail to meet the requirements of the project.

Also, it may form defects on the final aluminum component or part.

However, if you have an excessive allowance, you will encounter the following:

  • Increase the time needed to complete the task
  • Increase the labor hours
  • Increase the total manufacturing cost

What Are Some Design Requirements For Aluminum High-Pressure Die Casting Parts?

During the design process of aluminum high-pressure die casting parts, you need to consider the use, appearance, accuracy, cost, and performance.

Ensure you balance your design needs with the budget you have.

Here are factors worth considering when designing aluminum high-pressure die casting parts:


When designing the parts, you need to factor in the usage as the aluminum parts can have both cosmetic and structural applications.

The accuracy that you can attain with aluminum high-pressure die casting has increased as modern computer systems are becoming powerful.

Besides the parts having strong structural value, they also provide suitable cosmetic appeal.

Ensure you state the use of the aluminum component to the die casters.

This is because they can assist you in selecting the correct alloy and deciding on suitable tolerances for the application parameters.

Also consider factors such as conductivity, strength-to-weight ratio, corrosion resistance, etc.


The insides of aluminum high-pressure die casting have less significance.

However, the external parts are important when you will be using them in parts such as housing projects.

The clients always need an aesthetic appeal to the final product, and this means that besides the performance, aesthetics are important.

This means the external aluminum high-pressure die casting parts need to be externally appealing.

Furthermore, you can plan on the type of surface finish you would like to attain as it will also offer extra protection from harsh conditions.

An Appealing Aluminum High Pressure Die Cast

An Appealing High-Pressure Aluminum Die-Cast

Method Of Assembly

Assembling the aluminum parts can either be complex or simple and all this depends on the components.

However, you can segment complex components and join them later after completing the casting process.

Select the assembly method for your parts before starting the design process as the assembly method influences the design.

Besides, select the assembly method that caters to your needs.


Ensure you write down all budgetary details about your project.

This is because the budget will affect the aluminum high-pressure die casting process.

If you have experienced designers, they may lower the cost yet meet all the quality considerations for the aluminum parts.

Also, follow specific design rules to eliminate unnecessary costs due to overdesigning of components.

For instance, reducing sharp corners and undercuts can lower the cost and make it easy to conduct tooling and casting.

Are There Design Rules For Die Design That You Need To Adhere To When Performing Aluminum High-Pressure Die Casting?

Yes, there are design issues that you should factor in when designing the dies.

First, the die should allow the molten aluminum metal to easily flow within all cavities.

Also, it should be easy to remove the solid aluminum cast from the die, therefore, you should have draft angles to the walls of the cavity.

Furthermore, the die design should factor in complex features of the component like undercuts which need extra die pieces.

Besides, you should consider the material that you will use when designing the die.

There are different types of metals you can use when fabricating the dies.

The most common one is high-grade steel which you can use for between 100000 and 150000 cycles.

However, you can use steel with a low amount of carbon content as they are highly resistant to cracking.

Also, you can use this type for up to 1000000 cycles.

Some other die materials you can use include nickel alloys, vanadium, chromium, tungsten, and molybdenum.

Some other design rules to consider include:

  • Round corners as they lower fracture and stress concentration
  • Uniform wall thickness to ensure the cooling process happens uniformly and minimize defects
  • Apply draft angles to each wall which are parallel to parting direction to enhance component ejection
  • Use less number of external undercuts as they need side cores that will compound to the tooling cost

What Are The Causes And Solutions To Defects In Aluminum High-Pressure Die Casting?

Surface defects arise from the joining of two metal fronts.

The solution entails raising the mold temperature, lowering the feed time, and changing the feeding gate.

Lamination occurs when there is an improper follow of molten metal.

The solution entails inspection of the casting machine, stabilizing the process if increasing pressure, and adjusting the mold temperature.

Blisters that form from the feeding process can be solved by lowering the gas from the air.

Blisters Can Be Avoided By Lowereing The Gas In The Feeding Process

Blisters Can Be Avoided By Lowering The Gas Ih The Feeding Process

What Are Some Post-Treatment Processes That You Will Conduct Following Aluminum High-Pressure Die Casting?

Post-treatment allows you to obtain chemical and mechanical characteristics which untreated aluminum lacks.

Some of these processes include the following:

  • Heat treatment

This method will expose the aluminum cast to several temperature variations to enhance their metallurgical features like rigidity and ductility.

There are different heat treatment methods you can use such as:

  1. Stress relieving
  2. Quenching
  3. Annealing
  4. Age hardening
  5. Solution heat treatment
  6. Normalizing
  • Vacuum impregnation

Aluminum may contain internal porous structures that may affect the functionality of the part.

Vacuum impregnation will seal the pores without affecting the features of the final component.

  • Surface treatment

This entails using various techniques to enhance the appearance and mechanical characteristics of the surface material.

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