Die Casting Machine: The Ultimate FAQ Guide

This guide will help you choose a reliable and efficient die casting machine for your applications.

Whether you want to die cast aluminum, die cast copper, die cast zinc, die cast titanium or die cast magnesium, choose a suitable machine if fundamental.

Take a look:

What is a Die Casting Machine?

Die casting machines are equipment you can use to produce a textured surface, smooth, sharply defined, or accurately dimensioned metal parts.

You accomplish this by forcing molten metal into dies under high pressure.

The die, also known as a mold cavity, forms the shape of the finished metal.

You can use die casting machines to produce metal castings like zinc or aluminum die castings.

We rate die casting machines according to clamping force. This ranges between 35MN to 450kN.

Die casting machine

Another way of categorizing them is by their application.

The most common types are cold and hot chamber die casting machines.

What are the Components of a Die Casting Machine?

Each unit has different components depending on its type.

For example, a cold chamber dies extrusion machine has a cold chamber instead of a hot furnace as in the hot chamber variation.

Other parts like ejector pins, plungers, die cavities, and moving/fixed halves are present in both variations, just in different positions.

Regardless, they still perform similar purposes.

NOTE:

Each die casting machine has two halves, i.e., moving and fixed.

This simple configuration ensures the process is effective and highly efficient.

When the injected mold solidifies fast, you can open the movable die to take out the casting.

Parts of die casting machine

How Does Die Casting Machine Work?

Die casting machines work in four crucial steps, i.e., clamping, injection, cooling, and finally, ejection.

These machines involve the injection of melted nonferrous alloys such as zinc or aluminum into dies in the machine.

As indicated above, the two variations of die casting machines are:- cold and hot chamber machines.

Cold chamber die casting machines work more efficiently if your process involves high melting point alloys like aluminum.

Hot chamber machines work more efficiently if your process involves using low melting point alloys like zinc.

The steps involved in how both machines work are described in more detail below.

Clamping

This is the first step to using a die casting machine.

At this stage, you are required to prepare and clamp the two halves of the die, i.e., the movable and the fixed parts.

Cleaning and lubrication are required to ensure that the process runs smoothly.

You may do this after each cycle, or two depending on the material you are casting.

After doing so, you are required to attach both halves onto the machine and clamp them together securely.

Using sufficient force will ensure the die will be securely closed during the next stage, which is injection.

Injection

Here, you will transfer molten metal into a chamber for injection into the die.

The transfer methods vary depending upon the type of die casting machine you are using.

Normally, the injection pressure typically ranges between 1000 psi to 20000 psi.

This is an important consideration because the pressure will hold the metal in the die as it solidifies.

The amount of injected metal is known as the shot. Different shots may require different pressures.

Cooling

Once the injected metal gets into the die cavity, it starts solidifying as it cools.

When the whole cavity is filled, and the metal cools, the desired cast shape is produced. You should only open the die once the cooling time is complete and the casting is solid.

Cooling time may vary depending upon the thermodynamic characteristics of the metal, die complexity, or maximum casting wall thickness.

Larger wall thicknesses will take longer to cool, and so will geometrically complex castings.

Ejection

This is the final stage in the process.

After the cooling time has elapsed, you can open the die halves to remove the casting from the die cavity.

This is possible with the use of an ejection mechanism.

Once this process is complete, you can clamp the die shut and begin the process cycle again.

Note

An additional process known as trimming is also crucial to the die casting process. However, it is not included in the process cycle because it does not occur in the die casting machine as the rest.

Can You Use Aluminum Die Casting Machine for Other Metals?

Yes, you can use aluminum die casting machines to cast the following nonferrous metals:-

Zinc: Zinc alloys can be cast to form shapes with good impact strength, thin walls, corrosion resistance, and high dimensional accuracy/stability.

They are also considerably easier to die-cast than other alloys. The best alloys are Zamak 2, 3 &7, and ZA27.

Magnesium: Magnesium alloys are characterized by low density and excellent EMI and RFI properties.

This means they are easy to cast in both cold and hot chamber die casting machines. They also have good finishing properties.

The most common alloy is AZ91D.

Copper: Copper alloys are quite expensive but will provide high dimensional accuracy, high strength, and corrosion resistance.

A downside to using copper is that they have very high melting points, resulting in shortened die life.

Brass: Brass is a copper and zinc alloy which, in addition to being aesthetic, has the following qualities:-

spark resistance, low finishing costs, splendid corrosion resistance, etc.

You need to consider a few points before choosing which alloy to cast using your machine. These factors include:-

· Alloy strength

· Alloy density

· Alloy cost

· Alloy melting point

· Alloy corrosion resistance levels.

Which Types of Die Casting Machines Are There?

Die casting machine

Die casting machines are primarily categorized into two.

These types are hot and cold chamber die casting machines.

The classification methods vary depending on size and applications.

Cold Chamber Die Casting Machines.

Cold chamber die casting machines are best for applications that process metals for alloys that have relatively high melting points.

Examples of such alloys include magnesium, brass, and aluminium.

The units have compression chambers to which you will add molten metal.

There are two types of cold chamber die casting machines.

cold chamber die casting machine

They are classified as horizontal and vertical depending on which axis the compression piston moves.

Also, they require holding pots, sometimes known as ladles, to contain the melted metal alloys.

The ladle is kept separate from the unit. Its main purpose is to aid in pouring the melted metal into the die chamber.

Cold chamber die casting machines have a typical injection pressure that ranges between 2000 psi and 20000 psi.

Advantages of cold chamber die casting machines.

· They can produce large parts that weigh up to 20 kg.

· Cold chamber die casting machines can produce intricate shapes very easily.

· Cold chamber die casting machines are best suited for casting high-temperature copper alloys.

Disadvantages of cold chamber die casting machines

· Cold chamber die casting machines require an additional pouring system for the molten metal.

· Compared to the hot chamber die casting machine, cold chamber die casting machines have a longer process time cycle.

Hot Chamber Die Casting Machine.

These types of die casting machines are more appropriate for casting metals that have low melting points like lead, tin, or zinc.

The main parts of a hot chamber die casting unit include:

· A pumping system (nozzle, gooseneck passage, plunger, and a pressure cylinder.

· Steel pot containing melted metal.

The standard pressure for injecting melted metal into the die cavity ranges between 1000 psi and 5000 psi.

hot chamber die casting machine

The advantages of hot chamber die casting machines include:-

· They produce dimensionally close tolerances.

· They can produce thin-walled intricate shapes.

Some limitations include:-

· The hot chamber die casting machines can not produce heavy casts. They are appropriate for castings that are below 4.5 kg.

· You can only cast metals that have low melting temperatures like lead, tin, or zinc.

How Can You Increase of Efficiency Die Casting Machine?

Increasing the efficiency of your machine is important because it reduces production costs and makes production even faster.

· One way to increase the efficiency of your die casting machine is to use an AFD or adjustable frequency drive.

The adjustable frequency drive will make it possible to vary the pump motor speed. This will, in consequence, reduce the amount of waste energy without undermining other parameters.

· Another way would be to shorten cycle time.

Be sure to pay attention to different process parameters before you begin the die casting process.

This will enable the identification and definition of which process parameters to apply for your process.

It will also help to identify and eliminate potential process defects.

How Much Power Does Die Casting Machine Use?

Die casting machines are very energy-intensive.

They may create cost and sustainability issues to your process.

Heating metal alloys to their melting points require a lot of energy, as you may imagine. Moving them around and cooling them also requires a lot of electrical power.

Thus, energy costs can take up to a quarter of the entire die casting process costs.

It is also quite difficult to lower amount of electricity consumed by these machines.

This is because some specific stages of the die casting process can not occur without appropriate requisite conditions, including power.

So, how much power do they consume? They operate on 220V – 390 V.

These machines can run on 22KW motors and provide about 600 hours of efficient operation.

How Much Does Die Casting Machine Cost?

The price of a die casting machine ranges between USD 20,000 and USD 60,000, depending on its type and size.

The price is worth it because the units produce high-quality castings, are environmentally friendly, and are energy-saving.

The price accounts for only purchase costs and not shipping or maintenance.

The lead time on these machines is usually one month during peak season and fifteen working days during the offseason.

An agency of your choice should cover the export and import mode.

We also provide customizations such as packaging and logos at your request.

What Should Consider When Choosing Die Casting Machine?

Factors to consider include:-

i. The base of the machine. You should ensure that the base will hold the die casting unit before you decide to purchase one.

Different die casting machines have different sizes and injection systems.

ii. Die locking system. The die locking support mechanism should be adjustable to hold the specific types of dies that your process may require.

iii. Ton capacity. Die Casting machines come in different capacities.

Your choice should depend on the task you will require it to perform.

They are available in capacities ranging between eight and two hundred and fifty tons.

iv. Ejection and injection systems. Select a die casting machine with a hydraulic system that can efficiently inject the molten metal into the die cavity.

The best option would be to select a die casting machine that is high-pressure accumulator Powered.

v. Hydraulic systems. This part consists of an unloading valve, accumulator, vane pump, and a relief valve.

All these parts are available in different sizes, which are suitable for specific applications.

Identify the requirements for your process and then choose an appropriately sized die casting machine.

vi. Another important factor to consider is what materials you want to use. For example, if you are going to obtain zinc, tin, and lead castings.

In that case you should use a hot chamber die casting machine.

It is more appropriate for low melting temperature metals with proper fluidity.

Cold chamber die casting machines are best for applications that process metals for alloys that have relatively high melting points.

Examples of such alloys include magnesium, brass, and aluminum.

Choosing the right die casting machine goes a long way to ensure that your process produces quality castings without any hitches.

Be sure to thoroughly inspect the parameters above to aid your decision-making.

How Should You Maintain Die Casting Machine?

Die casting machine

Perform the following preventive procedures every eight hours or after each shift:-

· Inspect the lube system to ensure it is in good operating condition.

· Inspect the oil level in the air lubricators, safety bar, safety doors, and pump pressure configurations.

· Inspect the limit switch for damages or wear.

You can also request the services of specialized workshops that provide routine maintenance on the die casting machines.

They will check for technical capability and machine tools to ensure your unit is in peak working condition.

You should perform regular machine calibration on your die-casting units.

This will help the machine recover lost capabilities that arise from reduced clamping force or increased oil leaks.

If the levels of mechanical deterioration and wear are high, we recommend an exchange of parts.

The following are the components to recalibrate:-

· Casting pressure and injection speed.

· Flow pressure, volume, and other hydraulic features.

· Clamping force.

The die casting machines have consumable parts.

These are parts that may be in contact with moving parts, like parts with seals.

If they have been used for longer than intended, your die casting machine may lose some capabilities.

It is therefore recommended that you replace these parts periodically. They include toggle bushing, toggle pins, and cobel liners.

What Cause failure in Die Casting Machine?

You should follow the following steps if you begin to notice problems with your die casting machine, regardless of the type.

· Identify the symptoms and fault location by thoroughly inspecting the unit.

· Investigate the potential reason for failure.

· Inspect machine fault files and operation records.

The following are common causes of failure:-

Oil Pump Not Starting

This is caused by a closed or damaged thermal relay, malfunctioning power circuit, or damaged relay coil.

Reduced Total Pressure

This is caused by the reversed oil pump, improper valve adjustment, abnormal rectifier board, and abnormal pressure dial.

No Shot Action

This is caused by an abnormal automatic selection knob, damaged injection termination sensor, short injection time, or low hydraulic system pressure.

Shot Weakness

This may result in low-quality castings. Extremely low injection pressures cause it.

You need to conduct a speed fault analysis if low pressure is not the cause.

Other causes of failure include:-

· Casting inappropriate material.

· Thermal stress fatigue arises from the recurrent casting process cycles.

· Inhomogeneous and low initial die temperature.

For any questions or inquiry about die casting machine, contact us now.