Die Casting Zinc Alloy: The Ultimate FAQ Guide

If you have any question about die casting zinc alloy, you will find all information right here.

Whether you want to learn about different types of alloys, die casting techniques or any other feature – everything is right here.

So, keep reading to learn more.

What Are The Benefits Of Die Casting Zinc Alloy?

Some of the benefits are discussed below;

Die cast zinc alloy parts

Die cast zinc alloy parts

Stronger Parts, Thinner Walls

Compared to other materials such as aluminum and several types of plastics, zinc is found to be stronger than these other materials.

The strength property that zinc has makes it possible to produce zinc castings that have walls that are thinner and material that is less hence making their strengths optimized.

This is important as thinner walls with higher strength levels are achieved through using the die casting zinc alloys.

Faster Rates Of Production

A higher rate of production is achieved when using die casting zinc alloys compared to other materials used for the same purpose.

The zinc alloys need melting point temperatures that are lower, pressure injections that are high and also they have a higher cycle rate.

On cycle rate, the zinc alloys have a higher cycle rate of about 200% higher than other competing materials like aluminum.

For instance, aluminium should be ladled into a mold whereas zinc can be injected at very high rates this speeding up the production processes.

Also, the when it comes to solidification, the zinc alloys solidify at a faster rate thus making it possible to in production of many parts within the same amount of time.

It enables the customers and the production process to save on time and other production costs.

Zinc Alloys Have A Tighter Tolerance Requiring No Machining

With zinc alloys, parts with high quality and tighter tolerance levels are able to be produced as compared to other materials like plastic.

Another factor, the fluidity of zinc provides a great precision which allows their designs not to require other additional processes that are expensive such as machining.

Long Lasting Tools

Zinc die casting alloys have a zinc mold that is typical which is like 10 times longer than that of molds of aluminum.

Observing the some of the properties of zinc as a material, it has a melting point that is lower at the same time the material is less abrasive.

The properties makes zinc die casting alloys to have more life than their competitors.

The wear of zinc is less dramatic compared to the wear of other materials hence quality is maintained over a long period of time.

This saves the users with costs of replacement and repair as the alloys are lasting longer enough.

Die Casts Of Zinc Alloys Are Environmental Friendly

The material is environmental friendly as zinc is usually 100% recyclable.

This means that all the by-products of the casting process can be re-utilized through re-melting and casting without any degradation.

Other materials like plastic usually have a regrind property that makes it impossible for them to be unrecyclable.

Zinc has a melting point of about 800° F which requires lower levels of fuel in the production processes as it is low compared to aluminum that requires more fuel due to high melting points.

In conclusion, zinc has a carbon footprint that is smaller as compared to aluminum thus it is the greener option for the environment.

Flexibility In Design

Since the material has wear and bearing properties that are excellent, the zinc alloys allow surfaces to be able to act as bushings for the structures in motion.

Additionally, zinc can be formulated to be able in joining of materials hence doing away with the need of additional fasteners.

Therefore, these properties allows for great distinct designs that cannot be achieved using other materials.

Fewer Chances Of Failures

Alloys made of zinc, they are so tough and have a high level of fluidity in the event the alloys has be molten.

Through this, a resilient and a precise casting is produced that has a great rigidity and impact resistance than other materials like plastic and aluminum.

Surface Finishes

The surfaces of in casting allows for a great adhesion of numerous finishes to its substrates.

For instance, plating finishes and powder coatings usually provides decorative or functional requirements on the parts.

The finishes are great as they provide good attributes for corrosion resistance, visual aesthetics and increased levels of durability.

High pressure zinc die casting

High pressure zinc die casting

Are There Limitations Of Die Casting Zinc Alloy?

Yes, there are limitations of the die casting zinc alloys.

The limitations of the die casting zinc alloys include the following;

The Die Casting Zinc Alloys Have Poor Resistance To Corrosion

In the occasion where incidental elements of tin, lead and cadmium which have low levels of solubility in zinc alloy exceed required standards, the alloy suffers.

The zinc alloy casting suffers ductility decrease, volume swell hence making them vulnerable to breakage.

Also, intergranular electrochemical corrosion causes wearing and deformation of the parts of die cast zinc alloys.

High And Low Temperature

Die casting zinc alloy parts cannot be able to be used in both low temperatures and high temperatures.

When subjected to higher temperatures, the tensile strength goes down while in low temperatures, the impact properties are also going to fall.

Other limitations include;

When using zinc die casting most of the times, the casting has a tendency of yielding much heavier parts than most other alloys that re nonferrous hence it is not ideal for light weight applications.

Parts of zinc alloys casting become more fragile if the in the event they have been subjected to high levels of temperature.

How Does Hot Chamber Die Casting Zinc Alloy Work?

In this type of die casting, the metal heats up in a casting machine that is an attached.

The casting machines which are known as gooseneck, they feature a furnace that is built in which heats up the metal to a point it achieves a molten state.

A piston that is hydraulic powered is used to force pump the molten metal from the furnace into the die.

By using the hot chamber die casting process, a high productivity applications that do require outputs that are substantial are able to be achieved.

Below is the process of the hot chamber die casting alloy;

Hot Chamber Filling Up With The Liquid Metal

The shot cylinder that powers injection the injection stroke is normally located just above the molten metal supply.

The shot cylinder is connected to a plunger rod that is connected to the plunger.

The plunger then makes a contact with the metal that is already molten, and at the start of the casting cycle, the plunger is at the top of the hot chamber.

At this position, the molten liquid metal fills up the chamber by entering through the chamber through the intake ports.

Plunger Goes Down

During the onset of the cycle, the plunger sis pushed down by the short cylinder which forces it to travel down past the intake ports. Thus preventing the liquid from entering the hot chamber.

At this particular time, there is always an enough amount of the molten liquid in the hot chamber for the shot which fills the mold and is able to make a casting.

Plunger Going Down Further

At this point the plunger is always pushed down further which puts much pressure on the liquid metal thus forcing it into the die.

Pressure in the hot chamber die casting which should be exerted on the liquid metal for the die to get filled is about 700 – 5000 pounds per square inch.

For the casting to solidify, the pressure is held for quite some time until the solidification has taken place.

Plunger Goes Back To Its Original Position

The plunger should go back to its original position in order for it be there to perform the next cycle  hence it reverses and return back at the top of the hot chamber.

Through that, the intake ports are exposed that allows the liquid molten metal to pass through and fill up the hot chamber again.

There are several advantages of using the hot chamber die casting which includes the following;

Companies are able to create more products within a very short period of time thus improving their productivity, efficiency and reliability on satisfaction of customers.

There is experience of longer machine life as they are only exposed to metals that have a lower melting point.

The process is more efficient as the machines have an internal melting pot.

Also, the process is environmental friendly sine there is close to minimal in the metal wastes.

There is reduced porosity.

Hot chamber die castig process

Hot chamber die casting process

Which Zinc Alloys Are Suitable For Die Casting?

Zamak Alloy 2

Uniqueness

It has high hardness and resistance levels amongst other alloys of zinc.

The alloy contains relatively a high percentage of copper that makes it hard hence providing an excellent resistance to the alloy.

On performance, the alloy has a higher creep performance.

Properties

Physical properties

On density, the alloy has a metric of 6.6 g/cm3 and an imperial of 0.238lb/in3.

The melting point of the alloy ranges between 1435 – 1446 degrees centigrade and an imperial ranging between 2615 – 2635 f.

Mechanical Properties

The shear strength is bat 360 MPa while the imperial is at 52213.5 psi.

The tensile strength is at 317 MPa while the imperial is at 45976.9 psi.

Both the metric and the imperial of the elongation at break are at 7%.

The metric and imperial of brinell hardness lies at 100.

Thermal Properties

PropertyMetricImperial
Thermal conductivity105 W/mK729 BTU.in/hrft².°F
Thermal expansion co-efficient27.8 µm/m°C15.4 µin/in°F

Uses

Applications where this type of zinc alloy is used are;

It is applied in industrial tool injections.

They are used in metal forming dies.

They are applied in industrial fittings and gears.

Zamak 3 Alloy

This type of Zamak alloy is excellent in its applications because of its great castability and dimensional stabilities of a long period of time.

The dimensional stability of this alloys can be compared to other types of zinc alloys, however, it is only important when lower tolerances are required.

The alloy has low levels of resistance because of the low percentages of copper.

This alloy is excellent in the production of components that require surface treatments like chroming, plating and painting.

Physical Properties

The imperial of the melting point is at between 718-728°F while the metric is at 381-387°C.

The density lies on a metric of 6.6 g/cm3 while the imperial is at 0.24 lb/in3.

Mechanical Properties

The alloy has a tensile strength where the imperial is at 38900 psi while the metric is at 268 MPa.

The yield strength is at a metric of 208 MPa and an imperial of 30200 psi.

The Poisson’s ratio is at 0.27 on the metric and the imperial.

Both the imperial and the metric of elongation at break stands at 10%.

Both the imperial and the metric of brinell hardness stands at 82.

Thermal Properties

PropertyMetricImperial
Thermal conductivity113 W/mK65.3 BTU.in/hrft².°F
Thermal expansion co-efficient (@100-200°C/68-212°F)27.4, µm/m°C15.2 µin/in°F

Uses

Some of the uses include:

  • Plumber fittings
  • Ceiling fans
  • Blenders
  • Zippers

Zamak 5 Alloy

The alloys contains higher castability properties as compared to Zamak 3.

It has higher copper percentages that makes the alloy to possess higher resistance and hardness properties.

Also, the alloy also provides excellent creep performances.

Moreover, the alloy is also the needed choice when it comes to treatment of surface finishes.

Physical Properties

The imperial of the melting point is at between 717-727°F while the metric is at 380 -386°C.

The density lies on a metric of 6.6 g/cm3 while the imperial is at 0.24 lb/in3.

Mechanical Properties

The alloy has a tensile strength where the imperial is at 48000 psi while the metric is at 331 MPa.

The yield strength is at a metric of 295 MPa and an imperial of 43000 psi.

Both the imperial and the metric of elongation at break stands at 7%.

The brinell hardness has an imperial and a metric of 91.

Thermal Properties

PropertyMetricImperial
Thermal conductivity109 W/mK756 BTU.in/hrft².°F
Thermal expansion co-efficient27.4 µm/m°C15.2 µin/in°F

Uses

They are used in automotive

Also, they are used in toy die casting

They are used in the wheel balancing weights

ZA 8 Alloy

It has higher levels of aluminum as compared to other zinc alloys which now equips it with good hardness, creep performance and resistance.

The alloy is also ideal for surface finishes like painting.

Physical Properties

The alloy has a metric of 6.3 gm/cm3 and an imperial of 0.227 lb/in3 on the density.

Mechanical Properties

The alloy has a tensile strength where the imperial is at 38 ksi while the metric is at 263 MPa.

The yield strength is at a metric of 200 MPa and an imperial of 38 ksi.

Besides, the Poisson’s ratio is at 0.29 on the metric and the imperial.

The elasticity modulus imperial is at 12400 ksi while the metric is at 85.5 GPa.

Uses

They are used in bearings

Again, they are applied and used in thin wall decorations

How Does Cold Chamber Die Casting Zinc Work?

Here, the metal I heated in a different furnace to achieve a molten state.

The molten metal is then transported and poured to the machines chamber either using automatic ladle systems or manually using ladles.

After the molten metal is in the machine chamber, it is forced into the die at a high pressure using a hydraulic piston.

What Are The Applications Of Die Casting Zinc Alloys?

The applications of die casting zinc alloys include the following;

They are used in the automotive industries to make functioning power steering systems.

Furthermore, they are used in the making of the breaking systems and breaking parts in the automotive industries.

Besides, these alloys make the components of air conditioning and the entire systems.

They are used in the production and manufacture of electronic devices.

Again, they are also applied in the generation of fuel systems.

They are used in the production of interior aesthetic parts of automotive.

Are Die Cast Zinc Alloy Durable?

Yes, die cast zinc alloys are durable.

They are durable since zinc metal has excellent mechanical properties that can outshine other metal casts like that of magnesium, aluminum, bronze and other iron casts.

Which Defects Are Common When Die Casting Zinc Alloy?

Common defects during die casting zinc alloy include the following;

 Common die casting defects

Common die casting defects

Blisters

This is a surface defect where films of small surface blows on the component, the bubble formed is always hollow.

The causes of blisters are;

Lower die coat spray in the components.

High temperatures of the die.

Tool’s cooling jam moving side or fixed.

Blow Holes

This defect occurs when metals trap gases during the casting process.

Now when the casting cools, and solidification take place, bubbles structure in light of the point that the metal cannot hold much gas, the bubbles form.

The likely causes of the blow holes to form are;

Excess quantities of die coat spray.

Inadequate proper venting.

Steam trapped of die coat.

Cracks

During casting, cracks can occur at the end of the solidification process.

In the event the solidifying metal does not have enough strength to resist the tensile strength, cracks are going to appear during solidification process.

Causes leading to the cracks to occur are;

Low metal strengths.

High temperatures of the die.

Improper spraying.

Weight Less

This means that the castings are of less weight than the standard weights.

Weight less makes the casting strength to be reduced and also the quality of the casting I also reduced.

The causes that lead to such a defect include;

Molten metal was not well filled up in the mold cavity.

Runners being melted in the furnace.

Is High Pressure Die Casting Zinc Alloy Recommended?

Yes, high pressure is recommended in die casting zinc alloy to force the molten metal into the die.

Is There Minimal Wall Thickness For Die Casting Zinc Alloys?

Yes, there is a recommended minimum wall thickness for a die casting zinc alloy.

The minimum thickness is around 0.04 “.

Which Surface Finishes Can You Apply On Die Cast Zinc Alloys?

Surface finishes that can be applied on die cast zinc alloys include the following;

  • Polishing
  • Wire drawing
  • Electroplating
  • Sandblasting
  • Spraying

What Determines Cost Of Die Casting Zinc Alloys?

The cost of die casting zinc alloys is determined by the following aspects;

  • Production cost
  • Mold cost
  • Material cost

How Does Die Casting Zinc Alloys Compare To Die Casting Aluminum Alloys?

Zinc die casted alloys are suitable when it comes to smaller and thinner applications while the aluminum die cast alloys are suited for applications that are light.

Impact strength of zinc die cast materials is higher than of aluminum die cast material.

The zinc die cast alloys require less temperature unlike aluminum die cast alloys that require a higher temperature.

How Do You Test Quality Of Die Cast Zinc Alloy Parts?

Test quality of a die cast zinc alloy part can be done through the means of spectrometer analysis.

Also, a density measurement can be done to determine if the melt to be cast has the needed consistency and composition.

Which Is The Main Alloying Element In Die Cast Zinc Alloys?

Main alloying element in die cast zinc alloys is aluminum, copper and magnesium.

Dos Die Cast Zinc Alloy Parts Rust?

No, they do not rust.

Die Casting Zinc Alloys Vs Die Casting Magnesium Alloys; Which Is Better?

Zinc alloys is better than magnesium alloys.

Zinc alloys are way much stronger than the magnesium alloys and they also have an important benefit when it comes to corrosion resistance.

Therefore, alloys of zinc have more benefits.

For all your die casting zinc alloys, contact us now.

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