The die casting process is a manufacturing technology that allows for the high-volume production of parts that require high precision and complex designs. The process is suitable for metals, including zinc, magnesium, and aluminum. The most common comparison in metal manufacturing is between zinc die casting and aluminum die casting.
Both materials have unique features and applications. However, the technique enhances these characteristics. As a result, you must understand die casting and its impact on materials. This article compares aluminum die casting and zinc die casting. so you can grasp the differences and use the appropriate one.
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Differences Between Zinc Die Casting and Aluminum Die Casting
Aluminum die casting and zinc die casting have distinct characteristics that define their uses. The following are the common factors that can help you differentiate between both materials and choose the best one:
1.1 Weight
Zinc alloys have a high density comparable to steel, making them stronger and heavier than most die casting materials. Pure zinc has a specific density of 5g/cm3, while aluminum has 2.7g/cm3. Due to its high density, zinc die castings are more impact-resistant than aluminum die castings. It is therefore the material of choice for castings in structural applications.
1.2 Properties
Mechanical qualities are the primary distinguishing factor between zinc die casting and aluminum products. The following are the common properties and differences between both die-cast materials:
1.2.1 Melting Point
Although denser, zinc has a lower melting point (4200°C). The melting point is an important parameter in die casting because it specifies the type of die casting process that can be used. Zinc’s low melting point makes it more suitable for hot chamber die casting.
Aside from that, it prevents mold degradation, increases productivity, lowers manufacturing costs, and determines the casting process. On the other hand, aluminum has a higher melting point (6600 degrees Celsius). Aluminum is therefore more suitable for cold chamber die casting processes. This not only increases the cost but also the cycle time.
1.2.2 Thermal Conductivity
Zinc alloy has higher heat conductivity than aluminum die casting. Because it can efficiently absorb and dissipate heat. As a result, it is better suited for creating parts that generate a lot of heat or for working with heat that requires efficient heat dissipation.
Zinc castings are superior to aluminum castings in the production of die cast components such as heat sinks and electronics.
1.2.3 Corrosion Resistance
In addition, zinc castings have superior corrosion resistance than aluminum die-cast parts. As a result, the former is more suited to projects with extreme environmental conditions.
1.3 Tooling Life
Because zinc die casting is less abrasive and has a low melting point, molds do not need to be extremely strong. Because of these qualities (lower abrasiveness and melting point), mold damage and tooling costs are reduced. As a result, zinc molds can be used more than 1,000,000 times. Aluminum molds can only be used 100,000 times.
1.4 Surface Finishing
Unlike CNC machined parts, die castings often need secondary surface finishing options. Aside from the process, the type of material decides if the product requires surface finishing.
Zinc castings do not have pores after casting, as evidenced by their smoother/patterned surface. However, aluminum castings can form pores, pits, and blisters during casting. As a result, aluminum castings often require additional surface treatment methods.
Nevertheless, both castings can be surface-finished. In addition, zinc is more suitable for these surface treatment processes. For example, electroplating, powder coating, painting, plating, and anodizing.
1.5 Applications
Both materials are suitable for numerous industries. Zinc casting is stronger than aluminum casting. They are the most commonly used die casting choices for home appliances and automobiles.
On the other hand, aluminum castings have a higher strength-to-weight ratio. Therefore, this makes it the material of choice for lightweight but strong parts. This is a critical requirement for the usage of aluminum castings in the aerospace sector.
1.6 Cycle Time
Another important factor to consider in the aluminum die casting vs zinc die casting comparison is cycle time. In contrast to aluminum die casting, zinc die casting occurs under high pressure and has a low melting point. As a result, it has a shorter cycle time. And zinc casting has a 150-200% greater cycle rate than aluminum.
Furthermore, zinc die casting is heated within, as opposed to aluminum die casting, which uses a cold chamber method. Aside from that, zinc casting’s effective heat dissipation allows molten metal to solidify faster. As a result, cycle time will be reduced.
1.7 Costs
The cost of manufacturing is determined by a number of elements. Such as material costs, production processes, operator skills, cycle time, surface finishing, and so on.
| Zinc Die Casting | Aluminum Die Casting | |
| Weight | Higher | High |
| Melting point | Low | High |
| Thermal conductivity | High | Low |
| Corrosion resistance | Higher | Low |
| Tooling life | High tool longevity | Low tool longevity |
| Surface finishing | Low | |
| Applications | Automotive, marine, and electronic industry.
–Power steering system –Engine component –Fuel System |
Aerospace, house appliance, medical, automotive.
–Lawnmower parts –Power tools –Automotive components |
| Cycle time | Ten times higher | High |
| Costs | High | Low |
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When and Why Should You Choose Zinc Die Casting?
If you’re ever unsure whether to pick zinc die casting or aluminum die casting. Then consider the following criteria before making your decision.
2.1 Parts With Thin Walls
Zinc die casting offers excellent strength compared to other materials. It is therefore ideal for the production of thin-walled parts. When used, there is no need to worry about the part’s structural integrity because the material’s density contributes to its stability. Furthermore, this will lower the material and die-casting costs.
2.2 Harsh Environmental Conditions
Zinc die casting is suitable for tough environmental conditions. Particularly those that can contribute to corrosion. Zinc die castings have incredible corrosion resistance. This means that a protective coating is formed on the parts when used in these conditions.
2.3 Lesser Residual Stress
Die casting uses pressure to drive molten metal into the die. There are two pressure-based die casting methods: high pressure die casting and low pressure die casting. High-pressure die casting, on the other hand, usually produces residual stresses on the part.
On the other hand, zinc die casting takes place under low pressure. This decreases the residual stress on the parts.
2.4 Diecast Mold
When working with a fragile die casting mold, use zinc die casting. This is because such molds can survive up to ten times longer than aluminum die-casting molds. Furthermore, if you have a limited budget for tooling, consider zinc die casting.
2.5 Faster Production
Zinc alloys have a low melting point, necessitating a hot chamber die-casting process under high pressure injection. This will boost the cycle rate more than other materials. In zinc die casting, the zinc is melted in the machine. In aluminum die casting, the operator melts the aluminum outside the machine and then pours it into the injection machine.
When and Why Choose Aluminum Die Casting?
When deciding between aluminum die casting and zinc die casting parts, consider the following factors:
3.1 Strength-to-weight Ratio
Aluminum die cast parts are noted for their lightweight design and strong tensile strength. If you are looking for parts with such characteristics, you should consider them. Die cast aluminum parts are popular in the aerospace sector due to their lightweight design.
3.2 High Operating Temperatures
Aluminum die castings are the preferred material for operating at high temperatures, such as in metallurgy. This is due to their much higher melting point than zinc alloys. This ensures that they retain their structural and physical properties when exposed to such high temperatures.
3.3 Electrical Conductivity
Aluminum die-castings are extremely electrically conductive. This makes them an excellent choice for a variety of electronic die-cast components. For example, it is critical in EMI shielding to protect components from electromagnetic waves.
Order Your Zinc or Aluminum Die Casting Parts
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Yonglihao Machinery has extensive die casting skills to produce extremely tolerant and precise parts. This comprises cutting-edge facilities and an engineering team with extensive experience in die casting. Aside from production, we adhere to a thorough quality inspection process to ensure superior quality. You can get high-tolerance, precision zinc, and aluminum parts at a low cost and fast turnaround time.
Conclusion
Die castings made of aluminum and zinc are both strong and durable. However, selecting among any needs a comprehension of the materials’ inherent and die-casting-imposed qualities. These are the differences between zinc die castings and aluminum die castings. This allows you to make an informed decision on which die casting is best for your project.
FAQs
Are Zinc Die Casts More Durable than Aluminum Die Castings?
Zinc die casting parts are more durable than aluminum die casting. For the most part, zinc die casting is stronger than several common non-ferrous alloys. Zinc alloys are 2.5 times stronger than aluminum die casting.
What Are the Criteria that Differentiate Aluminum from Zinc Castings?
The two castings differ in weight, corrosion resistance, melting point, and thermal conductivity. Zinc casting is heavier, with a lower melting point, greater corrosion resistance, and superior thermal conductivity.
Which is More Corrosion-prone, Zinc or Aluminum?
Aluminum die casting parts are less corrosion-resistant than zinc casting. However, this is dependent on the pH. For example, in alkaline solutions (pH 11), aluminum casting corrosion resistance is the same as zinc.