Die casting is one of the processes that is employed in modern industries. It allows the manufacturers to produce highly complex metal parts in a very precise and reliable way. Among many other die-cast materials, Zinc and aluminum are the most widely used die-cast materials. Each of the materials has advantages and disadvantages.

The selection of the correct material is a very crucial decision. It has an impact on the performance of products, cost, durability, and efficiency of manufacture. A comparison is provided on zinc die casting and aluminum die casting in this paper. It explains their characteristics, strengths, weaknesses, applications and the price of the same.

Τι είναι η χύτευση;

Die casting refers to a metal forming process. Molten metal is under high pressure and forced into a hardened steel mould. The metal is poured into the cavity, and the metal will cure in the shortest possible time. The mould is opened afterwards, and an already completed part is removed.

This is an optimal process where there is a demand for mass production. It offers standardized quality and accuracy in size and surfaces with a smooth finish. The automotive, electronic, industrial machinery, medical devices and consumer products have die cast practice.

Overview of Zinc Die Casting

It is a process whereby a metal, typically zinc, is heated and poured into a mould full of wax. Zinc die casting is an accurate procedure for shaping metals. It is a process which involves a high pressure of molten zinc alloy injection into a hardened steel die. Normally, this pressure ranges from 700-4, 000 psi (5-28Mpa). This is the pressure that ensures the cavity is filled and reproduction is in great detail.

The die is molten and solidifies the metal at a high rate. After solidifying the die, opening the die is carried out, and the ejection of the part is complete. Most of its components do not require further or little machining.

Die casting with Zinc Alloys

Zinc die casting mainly deals with highly pure alloys of Zinc. The zinc percentage is normally 90-95%. The other composition is composed of aluminum, magnesium and copper.

Zinc die casting alloys are normally of the following types:

• Zamak 2 – Hardness and strength: High.
• Zamak 3 - Dimensional stability and surface finish are of high quality.
• Zamak 5 - Strength of greater superiority than that of Zamak 3.
• ZA-8, ZA-12 and ZA-27 – More aluminum in the building.

Only one of them, Zamak 3, has nearly 70% of the global die casting of zinc production due to its balance.

Melting Point and Saving of Energy

Zinc alloys have a very low melting point; that is, approximately 380-390 °C. This is a lot lower than the alloys of aluminum that will melt at about 660 °C.

Lower melting temperature is cheaper in terms of energy use since it uses approximately 30-40% of energy during the casting process. It also maintains the thermal stress of the die. As a consequence, zinc dies will be of 500000 cycles and above.

Dimensional Tolerances and Accuracies

Zinc die casting is characterized by a high amount of dimensional accuracy. Linear tolerances are usually within 0.025 mm to 25 mm of length.

In the majority of applications, overall part tolerances may be achieved to less than +-0.05mm without any post-machining. It is highly accurate, and it reduces the time and cost of production.

Finish, Aesthetic Quality and Surface

Zinc die-cast products are smooth in appearance when extruded out of the mould. Surface roughness values normally fall within the range of 1.6 -3.2 um.

The most adhesive surface treatments are zinc. The strength of zinc in chrome, nickel and decorative finishes is normally above 20 Mpa and this strength is attributed to the bond strength of electroplating.

Mechanical Properties of Zinc Die Casting Alloys

Zinc alloys are highly strong in terms of their part size. Common mechanical properties are:

• Ultimate tensile strength: 280-440Mpa
• Yield strength: 210-350 MPa
• Elongation: 7-15%
• Σκληρότητα: 80-120 HB

These values make zinc be utilized in wear and load-bearing components.

Velocity and Cycle of the Production

Die casting of zinc promotes quick cycles of manufacturing. The mean duration of the cycle is 5-15 seconds per shot.

This allows the production of over a million components per annum using one multi-cavity die. The cycle period is brief and increases productivity and reduces the unit cost.

This is possible by the use of thin-wall casting

Zinc alloys are very fluid. This allows thin-walled components down to a thickness of 0.5 – 0.75 mm.

In thin-wall casting, compact designs can be made and the amount of materials saved without compromising the structural integrity.

Part Size and Weight Range

Small to medium-sized components are better done using Zinc die casting. Normal weights of parts range between 5 grams and 3 kilograms.

This size range is uniform and could be applied to form complex shapes, and with a significant amount of detail.

Βιωσιμότητα και περιβάλλον

Zinc can be recycled with no loss of mechanical properties and 100%. Zinc die casting Scrap recovery is approximately greater than 95%.

Recycling zinc will consume much less energy, about 25-30 percent as compared to the primary production of zinc. This makes the zinc die casting an eco-friendly manufacturing product.

Weaknesses of Zinc Die Casting

Despite the fact that it is the best method, zinc die casting has its limitations. Zinc has a mass density of 6.6-6.8 g/cm3, which is more than twofold compared to aluminum.

Zinc alloys are also low-heat-resistant. Constant operating temperatures need to be suggested at temperatures less than 120 °C. Excessive temperatures can induce creep or deformation when exposed over a long period of time.

The prevalence of Zinc Die Casting

The zinc die casting is used in:

• Components of machinery and accuracy gears.
• Connectors and housings for electricity.
• Automotive interior parts
• Locks, hinges, and hardware
• Consumer electronic cases and enclosures.

The uses of zinc are favourable in the accuracy, strength and quality of the surface.

The merits and demerits of Zinc Die Casting

Benefits of Zinc Die Casting

Υψηλή διαστατική ακρίβεια

Χύτευση ψευδαργύρου are very precise regarding dimensions. Zinc alloy has minimal amounts of solidification shrinkage that tend to be less than 0.6. Through this, it is possible to have close tolerances like +-0.025 mm, considering 25 mm of part length.

The limitation of secondary machining also comes with high accuracy. This lowers the manufacturing time and cost.

Superior Surface Finish

Die-casts with Zinc have a smooth off-mould surface. The typical values of surface roughness are 1.6 to 3.2 um.

Zinc also bonds with coatings very well. Zinc-plated coating typically contains a bond strength of more than 20 Mpa. This makes zinc appropriate for decorative and functional finishes.

Low Melting Point and Energy Saving

The fusing temperature of zinc alloys ranges between 380 and 390 °C. This is nearly 40 per cent of the melting temperature of the aluminium alloys that melt at about 660 C.

Lower melting temperature will consume 30-40 per cent of power. It further reduces thermal fatigue on dies, reducing it to 500,000-100,000 cycles.

High Mechanical Strength of Minute-Sized Parts

In miniature designs, zinc alloys are highly strong. Common mechanical properties are:

• Ultimate tensile strength: 280-440Mpa
• Yield strength: 210-350 MPa
• Σκληρότητα: 80-120 HB

These properties of zinc enable it to be used in load-bearing and wear parts.

Γρήγοροι κύκλοι παραγωγής

Zinc solidifies quickly. Normal die casting cycle time is 5-15 seconds/shot.
The production rate is above 1 million parts per year, with short cycle times and a single mould. This makes zinc an appropriate in large scale production.

Better Thin-Wall Casting

Zinc alloys are very fluid. Very low thicknesses of the walls may be achieved (0.5-0.75 mm).
The thin-wall feature enables the designs to be reduced to small sizes and the materials to be saved without reducing the strength.

Material Utilization and Recyclability of the material is high

The scrap recovery of zinc die casting is more than 95%. Zinc can be recycled 100% of its mechanical qualities.
Recycling of zinc consumes approximately 25-30%  of the energy consumed during the primary production of zinc.

The Drawbacks of Zinc Die Casting

Heightened Density and Reduced Mass

Zinc has a mass density of approximately 6.6-6.8 g/ cm3. This is two times higher than the density of Aluminum which is 2.7 g/cm3.
Heavy parts should not be used in weight-sensitive applications such as aerospace and electric vehicles.

Limited Heat Resistance

Zinc alloys are not as thermally stable. Operating temperatures are normally not exceeded beyond 120 C.
Zinc may then creep at this temperature and lose its strength. This limits its use in high temperatures.

Limited Part Size Range

Small to medium-sized parts should be die-cast using zinc. Part weights range between 5 grams and 3 kilograms as normal weight.
Production of very large parts is not cost-effective due to the limitations of machines and material mass.

Long-Term Creep Behaviour

Constant load creep in zinc alloys is likely to occur. Stresses higher than 30-40per cent of the yield strength in the long-term exhibit the creep deformation.
This can disrupt the dimensional stability on which structural applications will be applied in the long run.

Decreased strength-to-weight ratio

Zinc is powerful, but its strength-to-weight ratio is less in comparison to aluminium. With a significant amount of less weight, aluminum can be utilized and it is ajust s powerful.
This makes zinc an inferior competitor to the light structural designs.

Material Cost Take into Consideration

The prices of zinc alloys usually cost more per kilogram than aluminum. Although the reduced machining helps to cover part of the expenses, there is a chance that the fluctuation of the prices of raw materials affects the economy.
Cost efficiency is extremely sensitive to the amount of production volume of production and the intricacy of the parts.

Introduction to Die Casting Aluminum

Aluminium Die Casting. This has been defined as the process of making castings by pouring molten aluminium into superrectangular moulds with rubber-filled rubber gaskets placed on the inside to enable the surface to harden.

Die casting aluminum can be defined as the process of producing metals which are used in the production of complex and lightweight elements. This process entails passing an alloy of molten aluminum in high pressure into a steel die. Injection pressure usually ranges between 1, 000 and 20, 000 psi (7-140 Mpa), depending on the size and complexity of parts.

The molten Aluminum fills the mold cavity fast and solidifies. The die will be hardened, and the component will be ejected. Die casting is mostly used in medium and big dimensions that require strength and low weight.

Aluminium Die casting Alloys

Typically, aluminum die casting is done using alloys that are aluminium-silicon. These are alloys that are excellent in fluidity, strength and corrosion.

Standard die casting alloys of aluminum are:

• A380 – It is the most common alloy that has reasonable strength and castability.
• A383 – The thin-wall component and complex component are smoothed out.
• A360 – Better ductility and corrosion resistance.
• ADC12 – used in electronics and automobiles.

The silicon concentration will normally fall within the range of 8-12 percent which makes it fluid and generates less shrinkage during solidification.

Temperature – Thermal and Meltdown Properties

The melting of the aluminum alloy is approximately 660-690 C and this is very high when compared to the melting point of zinc alloys. It has a high melting point, which is more power-consuming during casting.

The aluminum is, however, very thermally conductive. Thermal conductivity values, which are most prevalent, are between 90 and 155 W/mK, and the best suited one to utilize as a heat-sink item is aluminum which may be utilized in the shape of heat sinks or an electronic housing.

Dimensional Tolerances and Accuracies

The case of aluminum die casting is good, but not as tight as zinc. Normal tolerances are -0.1 – +- 0.2mm/25 mm of part length.

Below 1.0-1.3 is weak shrinkage sintering of aluminium. This has led to it becoming a fact that the use of precision features is, in the majority of occasions, something that is subject to secondary machining.

Hammermen of Surface and Concrete

The standard 3.2 6.3 um is the variety of surface roughness of aluminum die-cast items. This is the case in the majority of the applications, though finishing on the decorative parts can be done further.

The aluminum finishing can be obtained through anodising technique, and the finishing, or the powder coating can also be obtained through anodising technique. A nodular aluminium has superior corrosion and hardness.

Die Casting Alloy of Mechanical Aluminum

Aluminium alloys die castings have strong weight ratios. Mechanical properties shared by it are:

• Highest tensile strength: 220 MPa- 330 MPa.
• Yield strength: 130-180 MPa
• Elongation: 2-10%
• Σκληρότητα: 70-100 HB

Such properties make aluminum suitable for load-bearing and structural aspects.

Ελαφρύ πλεονέκτημα

Aluminum has a density of around 2.7 g/cm 3, and it is nearly 60 times lower than that of zinc. This type of weight saving is necessary in the automotive, aerospace and electric car segments.

A reduced weight of components also means high fuel economy and low weight of the system load.

Speed and Turnaround of Production

Aluminium die-casting is a process that takes longer than zinc die-casting. Complexity and thickness. The parts are 20-60 seconds/shot.

Both medium and high volumes with slow cycles are still cost-effective using aluminum die casting.

Large and complicated parts capacity

Die castings that are modelled in aluminum can hold bigger parts as compared to those modeled in zinc. Parts weighing greater than up to 15-20 kg can be made using a high pressure die casting equipment.

This is the reason why the aluminum can also be utilized in the engine cases, transmission cases and structural frames.

Corrosion Protection and Environmental Performance

Passive corrosion is one of the natural constructions that is prepped with the help of aluminum that creates an oxide. This makes the utilization of aluminum in outdoor and marine designs.

Aluminum is 100% recyclable. This is because recycling of aluminum has been reported to consume 5 per cent of the energy that is used to produce mainly aluminum, and thus recycling consumes a lot of energy.

Die-cast aluminium has been used in applications

It is applied in other works in:

• Parts of the Carmotor engine and transmission.
• Battery case of electric vehicles.
• Heat sinks and Electronic enclosures.
• Aerospace structural parts
• Industrial machine components.

Die Casting Aluminum has its disadvantages and advantages

The merits of Aluminum die cast

Lightweight Material

The density of aluminum is low, and it is approximately 2.7 g/cm3. This makes aluminum pieces nearly 60 percent light than zinc and much lighter than steel.

The decrease in weight increases the automobile’s fuel efficiency. It also reduces the weight in the construction of machines and electronic systems.

Weight to strength Ratio is high

The alloys of aluminum die casting are effective in terms of mechanical strength, but are light. Some of the mechanical properties are common, and they include the following:

• Maximum tensile strength: 220- 330 Mpa.
• Yield strength: 130-180 MPa

It is the combination of the two that allows aluminum to be the most suitable in the sphere of structure and load-bearing.

Outstanding Quality Corrosion Resistance

The aluminium is naturally gifted with the capability of coating itself with an oxide coat. In most instances, the coating prevents oxidation and rust.

In a damp climatic environment, marine/outdoor has been an excellent product. The atmospheric exposure rate of corrosion is less than 0.05 mm/ year.

Καλή θερμική αγωγιμότητα

Aluminium is a thermal conductor with thermal conductivity being 90-155 W /mK. This will ensure that heat is dissipated easily.

This is the material that causes aluminum to be utilized in heat sinks, engine components and electronic cases.

Skill of high and complicated parts

Huge parts are cast in aluminum. Components that have a mass of up to 15- 20 kg can be made through high-pressure die casting machines.

This makes aluminum to be adequate in the engine blocks, transmission housing and structural frames.

High temperature dimensional Stability

Aluminum is more resistant to heat, which is greater than zinc. The majority of alloys are workable at 200-250 C.

This makes use of aluminium in high temperatures.

Big Recyclability and Sustainability

Aluminum is 100% recyclable. Compared to the primary production of aluminum materials, it consumes half of the energy that is used in recycling aluminum.

This helps much in minimizing effects of polluting the environment and production expenses.

Disadvantages of Die Casting of Aluminum

High Melting Temperature

Aluminum melts at a temperature of 660-690 deg C. This is a greater fusing point and as such thus consumes more energy in casting.

The temperature is high and this means that there is high thermal stress on the moulds. The quality of dies is what determines the average life of the mould, and it varies between 100 and 300 cycles.

Cast to Zinc with Smaller Lower Dimensional Precision

Aluminum also contracts more in the solidifying process, and the natural contraction is 1.0-1.3%.

As a result of this, there are weaker tolerances. These tolerances are often +0.2 -0.1 mm/25 mm. Often, it requires secondary machining.

Rougher Surface Finish

Aluminum die-casts normally have an approximate value of 3.2-6.3 um on the surface roughness.
The decorative processes may also require other finishing, e.g. machining, polishing or coating.

Reduced Flexible Production Cycle Time

Aluminium also requires a long period of time to cool down compared to zinc. The shot takes up to 20-60 seconds.
The cost of long cycle time reduces the high-volume manufacturing.

Tooling and Maintenance Cost increase

The operating temperatures are high, and hence, wear out of aluminum dies is increased. The tooling is also very costly as opposed to zinc die casting.
The dimensional accuracy and the surface quality are usually maintained by means of maintenance.

Porosity Challenges

The aluminium has gas porosity that is likely to be die-cast. The porosity that commonly occurs when the process control is not optimal is the porosity of 1-3 per cent.
Any porosity can cause a loss in mechanical strength and limit its usage to tight pressure.

Σχετικά με την GC Precision Mould

The Chinese company identified with die castings is GC Precision Mould. We celebrate our 20 th anniversary of delivering quality and precision metal parts.

Οι υπηρεσίες μας

We are also involved in the die casting of aluminum, zinc and magnesium. We possess the resources of mould designing, high-pressure die casting, CNC machining and finishing of surfaces. We have the projects in the idea stage, all the way up to the stage of finalization of the product.

Quality and Applications

We have a good quality of components. They find application in the automobile, electrical, hardware and industrial sectors.

Γιατί να μας επιλέξετε;

Pick GC Precision Mould that is precise, durable and dependable. We offer low-cost services to meet your needs.

Συμπέρασμα

Die casting (Zinc and die casting Aluminum) plays a crucial role in the modern world of manufacturing. These two materials are associated with several strengths and weaknesses.

Zinc is also not poor in terms of precision, finishing and fast manufacturing. Aluminum boasts of light weight, corrosion and heat control superiority.

It lacks the final best alternative. The appropriate choice would be made depending on the requirements of design, operational requirements, cost objectives and applications.

The advantages and disadvantages of the two materials would help the manufacturers to make the right choices. This leads to the quality of the goods, success and efficiency in the long-term.

Συχνές ερωτήσεις

What are your raw materials, die cast?

These are aluminium alloys, zinc and magnesium alloys. They are composed of materials which are highly precise, tough and high grade surface finish, which can be used in various activities.

So what are the services of GC Precision Mould?

We propose a total die casting job, and this will include high-pressure die casting, CNC machining, surface finishing and design of moulds. We stick to nothing till the end.

What industries do you serve?

Our business is automotive, electronic, hardware and industrial. We possess high-performance and high-quality custom parts.

What is your quality assurance to customers on products?

The quality control measures in all the stages are very strict, with state-of-the-art inspection equipment and testing. Our goods are expected to be extremely accurate, robust and satisfying to the customer.

What is the reason to decide to favour GC Precision Mould?

Choose GC Precision Mould since it has accuracy, reliability and is cost-effective in die cast solutions. We are over 20 years old, and this will enable us to offer you personal solutions to the problems.