A356 Aluminum Alloy: The Ultimate FAQ Guide

Choosing a suitable A356 aluminum alloy for die casting process can be a challenging task without the right information.

It is for this reason that this guide will explore all the fundamental aspects of this aluminum alloy.

Keep reading to learn more.

What Is A356 Aluminum Alloy?

The A356 aluminum alloy is a composition of 92.05% Aluminum, 7% Silicon, 0.2% iron, 0.35% Magnesium, 0.2% Copper, Manganese and Zinc are 0.1% each.

The parent metal of this alloy is aluminum since it makes up 92% of the material.

Since the alloy has excellent machining and casting properties it is used in heat treatment procedures of T5 and T6.

The alloy is light and resistant to corrosion and can be compared to stainless steel.

The A in front of an alloy simply denotes a higher purity form of the alloy composition.

A356 aluminum alloy

A356 aluminum alloy

What Are The Physical Features Of A356 Aluminum Alloy?

Before choosing A356 aluminum alloy, it is important to examine all the physical features.

This way, you will make informed decision in the subsequent die casting processes.

Some of the notable features include:

  • It is a lightweight aluminum alloy – therefore, when you want to reduce the overall weight of structural components, while maintaining the desirable properties of aluminum, then it’s a perfect choice.
  • Excellent corrosion resistance – in most instance, it will substitute aluminum alloy 6061. In fact, A356 aluminum alloy corrosion resistance properties is similar to that of stainless steel.
  • Good welding properties – you can easily weld A356 aluminum alloy. This makes fabrication process easy and cost-effective.
  • It has low level of impurities – this contributes to its good ductility and high strength. Therefore, it is a perfect choice for most structural components.
  • Good machining properties – you can easily machine A356 aluminum alloy depending on your unique specifications.

Which Aluminum Alloy Can You As Alternative To A356 Aluminum Alloy?

In most case, you can use aluminum alloy 6061.

In fact, their properties are closely related as you can see in the table below;

Property Of Aluminum MaterialA356 Aluminum Alloy 6061 Aluminum Alloy (T6 Heat Treated)
Elongation at break1% to 6%10%
Density2.6 g/cm32.7 g/cm3
Fatigue strength50-90 MPa96 MPa
Thermal expansion21 µm/ m-k24 µm/m-k
Shear modulus26 GPa26 GPa
Thermal conductivity150 W/m-k170 W/m-k
Ultimate tensile strength160-270 MPa310 MPa
Melting onset570 Degrees Celsius580 Degrees Celsius
Yield strength83 – 200 MPa270 MPa

It is important to note that the variations in the A356 alloy in some properties is due to different heat treatments.

What Are The Mechanical Properties Of A356 Aluminum Alloy?

As you evaluate the mechanical properties of A356 aluminum alloy, you should consider the various heat treatment.

In most cases, opting for T5 heat treatment or T6 heat treatment will only increase the hardness of A356 aluminum alloy.

Under normal circumstances, T6 heat treatment will increase the hardness of A356 aluminum alloy by 12 to 15 Webster hardness.

Of course, it will also improve other mechanical properties for better die casting results.

Below are mechanical properties for A356 aluminum alloy that has been subjected to T6 heat treatment process:

Mechanical Property Of T6 Heat Treated A356 Aluminum AlloyQuantity
Brinell Hardness70 to 105
Ultimate tensile strength>= 34000 psi
Rockwell (A) Hardness37
Shear modulus and Shear Strength3950ksi and 20700 psi
Vickers Hardness99
Machiability50%
Rockwell (B) Hardness55
Poissons ratio0.33
Yield strength>= 24000 psi; @Strain 0.200 %
Knoop Hardness112
Tensile modulus10500 ksi
Elongation at break>= 3.5 %

Note: Use this for reference. The values may vary depending on the quality of a356 aluminum alloy.

How Strong Is A356 Aluminum Alloy?

The alloy is very strong and durable.

It is for this reason that you can you to die cast items that require high-strength material.

Due to its excellent strength, you can use it in applications that require high pressure tightness.

So depending on the specific application, you can choose either T5 or T6 heat treated A356 aluminum alloy.

Can You Weld A356 Aluminum Alloy?

Welding aluminum alloy

Welding aluminum alloy

Yes, A356 aluminum alloy can be welded though the procedure is a bit complicated.

When welding the A356 alloy, the heat from welding will affect the surface hence reducing the mechanical properties of the alloy.

You have to be very careful when choosing your filler alloy for welding, which is dependent on the type of heat treatment given to the casting after welding.

Also always ensure that the strength of the casting is uniform to avoid having weak points and strong points on your alloy after undergoing the heat treatment process.

What Are The Applications Of A356 Aluminum Alloy?

You can use this aluminum alloy in many applications such as:

  • Manufacture of aircraft parts due to its lightweight and high strength
  • The alloy is also used in the manufacture of high-velocity blowers.
  • You use the alloy in the manufacture of impellers as well as the pump housing.
  • Firearms and equipment
  • Medical equipment
  • Automotive components such as oil pans and transmission cases
  • Housings, plates and covers

In short, any applications that requires corrosions resistant, light-weight and high strength metal, A356 aluminum alloy is always a perfect choice.

What Are The Chemical Properties A356 Aluminum Alloy?

A356 aluminum alloy has a composition of 7 chemicals each with different percentages.

Aluminum carries the bigger percentage of the composition of the alloy being at 92%.

The other chemicals combined with aluminum to create the alloy are silicon, zinc, manganese, iron, magnesium, and copper.

These chemicals sum up to 8%  and when added to the percentage of the aluminum used it gives us 100% composition of the alloy.

Is A356 Aluminum Alloy Best For Die Casting?

Yes, A356 aluminum iron is best for die casting.

You can use both low pressure and gravity die casting aluminum alloy.

This is simply because the surface of the A356 aluminum alloy is smooth making it effective for casting.

The die casting process will enable you to have high-quality alloy castings.

How Is A356 Aluminum Alloy Heat Treatment Process Done?

There are two types of the heat treatment process for A356 aluminum alloy.

  • T5; here the aluminum extruded from the extruder air cools naturally.The treatment process will result in casting with Webster scale hardness ranging in between 8-12.
  • T6; this treatment process is quite complex.The process will require the aluminum extruded from the extruder to be water-cooled immediately.

Here, the process increases the Webster hardness scale to range between 12 and 15.

This process also increases the mechanical properties of the casting.

What Are The Standards Of A356 Aluminum Alloy?

  • Quality level; this standard ensures that your alloy quality has the capability of doing the job which it is designed to do.
  • Frequency level; this standard ensures that the alloy is inspected to ensure compliance for your alloy to satisfy the quality level required.

When the two standards are achieved, they ensure that the quality of your A356 aluminum alloy is top-notch.

Also, the A356 alloy produced by these standards is visually inspected to ensure that no cracks were formed in the alloying process.

What Are The Alloying Elements In A356 Aluminum Alloy?

A356 aluminum alloy is a composition of different elements used to form the alloy.

The elements are aluminum, zinc, silicon, magnesium, manganese, iron, and copper.

  • Aluminum; comprises 92.05% of the alloy hence taking the larger part of the alloy composition.
    Aluminum is perfect when it comes to corrosion resistance hence used.
    Also, aluminum itself has effective workability.
    Aluminum alloy is used in high pressure casting parts and since aluminum has high thermal conductivity it is used in making the alloy
  • Copper; takes 0.2% of the total alloy composition.
    You use copper in making the alloy simply because it provides strength and also enables the hardening of precipitation.
    Copper is also added because it reduces ductility as well as corrosion resistance.
    Adding to that, because of its high strength, it is added to the alloy to increase its strength when dealing with heat-treatable alloys.
  • Silicon; takes up 7% of the total A356 aluminum alloy composition.
    Addition of silicon to the A356 alloy because its presence in the alloy reduces the melting point of the alloy.
    By reducing the melting point, you will enhance the fluidity of the alloy.
    The presence of silicon in the alloy enables the alloy to be used in the manufacturing of casting.
    It also enables the alloy to be used as filler wires used in fusion welding.
  • Zinc; makes up 0.1% of the total composition of the alloy.
    Zinc will add strength and also allow precipitation hardening.
  • Iron; its total percentage in the alloy composition is 0.2%.
    It is added to increase the strength of the alloy.
  • Magnesium; takes up 0.35% of the alloy composition.
    The alloy benefits from its addition since it improves the strain hardening of the alloy.
  • Manganese; 0.1% is what it takes up in the alloy composition.
  • It is added to get better results during work hardening.

Can You Anodize A356 Aluminum Alloy?

Yes, you can anodize A356 aluminum alloy.

The process of anodization will involve silicon inclusions giving the alloy a darker color.

Also, the process will improve the corrosion resistance of your alloy.

What Is The Cost Of A356 Aluminum Alloy?

The cost of purchasing A356 aluminum alloy is generally expensive compared to other alloys of aluminum.

This is simply because the alloy is in its purest form.

The cost of your A356 aluminum alloy will range from around 12 US dollars per kilogram.

What Are The Benefits Of Using A356 Aluminum Alloy?

The alloy has excellent corrosion resistance.

Your alloy has very good weldability characteristics.

Also, when given an aging treatment, this alloy’s mechanical properties are rated excellent.

A356 has low levels of impurities hence has high ductility and strength.

What Are Some Of The Limitations Of A356 Aluminum Alloy?

The process of alloying the aluminum to A356 aluminum alloy is very expensive therefore making the alloy also expensive.

The alloy is not strong when you compare it to the steel of the same strength.

How Can You Verify Quality Of A356 Aluminum Alloy?

  • Optical Emission spectrometry; this method is excellent for rapid analysis of high purity A356 aluminum alloy.
    Here the sample is prepared using a lathe or milling machine, do not use a grinding machine because it risks contamination.
    Once you have prepared the sample, the overall time required to analyze and check its quality is on an average of 30 seconds.
    The optical emission spectrometry analyzes the contamination of over 34 contaminants in the aluminum alloy.
    Accuracy is determined by precise calibration in the factory during the manufacturing process of the alloy.
    Always use the best practices in sample analyses, this includes completing decontamination runs in the alloy after higher concentration samples have been analyzed.

What Are The Effects Of Natural Aging  On The Properties Of Heat Treated A356 Aluminum Alloy?

When you use natural aging on properties of heat-treated with the A356 aluminum alloy, you reduce their electrical conductivity.

Also, natural aging improves the yield strength of properties of heat-treated with your A356 aluminum alloy.

Natural aging of these properties with A356 aluminum will also yield their microhardness.

What Is The Correct Procedure For Alloying A356 Aluminum Alloy?

The best procedure for alloying A356 aluminum alloy is metallurgy.

Here, you mix the metals that are supposed to make up the alloy in the molten state.

So first you melt the major metal and then followed by the other metals that will be used to make your alloy.

After adding the rest of the metals, ensure that they completely dissolve.

Since the metals are in a molten state, pour the mixture into metal or sand molds and allow it to solidify and cool.

Can You Extrude A356 Aluminum Alloy?

A356 aluminum alloy can be extruded.

The extrusion process is done to the alloy to induce severe plastic deformation.

This helps improve the casting microstructures at temperatures that range from 490 to 540 degrees Celcius and with different feed rates.

How Does A356 Aluminum Alloy Compare To A 357 Aluminum?

A357 aluminum alloy contains larger magnesium content compared to A356  alloy hence can be heat treated to higher strength levels.

Also, the A3557 alloy has small amounts of beryllium while A356 does not have.

The beryllium presents an inherent safety hazard to the alloy.

A356 aluminum alloy cast component

A356 aluminum alloy cast component

What Are The Processing Properties Of A356 Aluminum Alloy?

We process A356 aluminum alloy to make various parts through die casting.

Whether you want to make simple or complex parts from A356 aluminum alloy, you must understand the various process temperatures.

Some of the critical processing temperatures you should know include:

Property/Process
Temperature in °F
Casting Temperature1250 to 1450
Melt Temperature1250 to 1500
Aging Temperature305 to 315 (Note that during this process, you should maintain this temperature for 2 to 5 hours)
Solution Temperature995 to 1005 (Note: You can maintain this temperature for 12 hours after which you can cool in water at a temperature of 150 to 212)

Also, note that the value on the table are for T6 heat treated A356 aluminum alloy.

Which Surface Treatments Can You Recommend For A356 Aluminum Alloy Die Cast Components?

Choosing a specific surface treatment will depend on the final surface finish you need.

The best part, A356 aluminum alloy is compatible with virtually all surface finishes.

Depending on your needs, you can choose any of the following:

What Are The Different Variations Of A356 Aluminum Alloy?

You can choose any of the following variations of A356 aluminum alloy A356.0; A356.1 or A356.2.

Remember, these variations are due to the chemical composition of each alloy as you can see below:

A356 Aluminum AlloyMn amount in %Si amount in %Zn amount in %Mg

Amount in %

Cu

Amount in %

Fe

Amount in %

Ti

Amount in %

Al amount in %
A356.00.16.5 to 7.50.10.25 to 0.450.20.20.2Remaining %
A356.10.16.5 to 7.50.10.3 to 0.450.20.150.2Remaining %
A356.20.056.5 to 7.50.050.3 to 0.450.10.120.2Remaining %

Depending on your unique applications and requirements, we will help you choose high quality A356 aluminum alloy for your unique applications – contact us today.

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