High-pressure die casting uses zinc to make strong parts. Zinc alloys are easy to shape in this process. This makes lots of parts quickly and cheaply. Zinc parts made this way are strong and last a long time.

This article shares several proven benefits of using zinc alloys in HPDC. Which therefore makes them a popular choice for almost every industry.

What is Zinc Alloy? Definition

Zinc alloys are mostly zinc, but they also have small amounts of other metals like aluminum, magnesium, and copper mixed in. These additions make the zinc stronger, more flexible, and less likely to rust. For example, adding aluminum makes the zinc harder, while magnesium helps it resist bending over time. This information comes from scientific studies and industry reports.

Benefits of Zinc Alloys in High-Pressure Die Casting

Strength and Density Comparison

Most of the zinc alloys give you the best strength. They make lightweight parts via high-pressure die casting. The standard options include:

• Zamak 3 offers tensile strength up to 268 MPa with density volume of 6.6 g/cm³
• The availability of tensile strength in Zamak 5 Tensile is 331 MPa with a mass of volume 6.6 g/cm³
• Zamak 2 provides 400 MPa tensile strength along with a density of 7 g/cm³.

Effect of Magnesium (Mg) Addition

The composition of magnesium (Mg) with zinc alloys increases tensile strength. For example, adding 0.02% Mg to zinc offers 268 MPa tensile strength.

Meanwhile, the increase in mg amount to 0.08% also raises tensile strength up to  310 MPa. In spite of that, using more Mg content in zinc reduces elongation. This means the metal can be stronger but does not offer much flexibility.

Microstructure and Application

When you add Mg to zinc, it tightens its microstructure. This is because it forms fine grains and hard phases like η and ε. All these changes also increase the overall zinc strength.

Additionally, combining a very low amount of copper (Cu) can better the hardness. For instance, Zamak 5 with 1% Cu gets a Brinell hardness of 82 HB.

Impact Resistance and Wear Strength

You know, zinc not only gives higher tensile strength but also resists impact. For instance, Zamak 2 has 43 J/m impact strength, which is somehow well-suited for parts exposed to unexpected forces.

Additionally, applying a coating (TiN or nickel) on zinc alloys increases its wear resistance. These coated alloys then work best for high-friction parts. For instance, mechanical joints and locking mechanisms.

Lower Melting Point and Improved Flow

Zinc alloys have lower melting points (385°C) as compared to aluminum (660°C). They easily melt and flow evenly in the mould. Typically, during HPDC, the die temperature ranges from 150-200°C. It uses injection pressure between 500 and 1500 bar.

High Precision and Dimensional Stability

Usually, zinc alloys offer sharply defined outputs with tolerances of ±0.05 mm. This tolerance level is better than aluminum (±0.1 mm).

The improvement in accuracy also depends on the alloy’s high fluidity and low melting point. This is why zinc is definitely suitable for making fine, detailed parts of electrical connectors and camera housings.

Reduced Defects and Improved Mold Filling

Among other zinc alloys, Zamak 3 can smoothly fill thin mold inner sections. They make fewer defects, like cracks. Therefore, you can use them to make parts that must not be varied and contain exact shapes.

Superior Corrosion Resistance

Zamak 3 and 5 impressively stop affecting corrosion or rust. For instance, during salt spray tests (ASTM B117), they show 3 times better corrosion rate of <0.1 mm/year than aluminium

Protective Layer Formation

Zinc alloys form a natural protective layer (zinc carbonate, zinc oxide) called patina or passivations. These layers resist the effects of water, soil or air. Additionally, you can increase their protection capability by just adding 4% aluminum.

Additional Coatings for Durability

As you know, bathroom fixtures are exposed to water or soap frequently. In this case, coatings such as plating and chromatin play a key role. They increase the durability of zinc.

Faster Production

Molten zinc in dies cools down 30–50% faster than aluminum, converting into a net-shape. They take less cooling and increase production rates.

Superior Surface Finish and Reduced Machining

Using zinc in HPDC produces superior surface finishes ( Ra 0.4–0.8 µm). That also let you skip the further surface treatments.

These alloys can replicate very fine details (0.025 mm). That means they are ideal for logos, thin wales and decorative projects needing less matching time.

Enhanced Electrical and Thermal Conductivity

Zinc alloys give you 27% IACS electrical conductivity. Their thermal conductivity of 113 W/m·K is sufficient to defend against intense heat. That is important for electronic housing and heat sinks.

High Fatigue Strength for Moving Components

Regarding repeated stress, a zinc fatigue strength of 35–70 MPa handles them better. This property is mainly ideal for hinges, locks, and mechanical linkages.

Cost Advantages of Zinc Alloys

In the case of affordability, zinc alloys lead because of their lower processing costs than aluminum. Let’s break it down in the following:

• The zinc alloy cost can be different in each region; however, it typically ranges from $3/kg (vs. $4.5/kg for aluminum).
• Their tooling cost is 20% cheaper also because of the better lastability of zinc than aluminum dies.
• They use less energy (30% lower) due to their low melting point.

Sustainability and Environmental Benefits

You can reuse zinc products by recycling them and getting 90% content. For this process, zinc consumes 75% less energy and can produce new material. Also, studies show zinc die casting effectively reduces CO₂ emissions.

Applications of Zinc Alloys in HPDC

1.   Automotive: Precision Parts for Better Performance

The automotive industry uses zinc alloys, especially make Zamak 5 with 1% Cu, to make carburettor housings, fuel pumps, and throttle bodies.

They prefer this option because of its higher tensile strength and ability to stop wear. This, therefore, means that the parts can handle engine heat and vibrations. These alloys also reduce product weight and improve fuel efficiency.

Looking at the image, you will find out how important zinc die-casting is in automotive components.

It shows you can produce a variety of difficult-shaped parts. For instance, gears, levers and structural body. The door interior also demonstrates executive quality and finishing.

2.   Aerospace: Lightweight, Reliable Components

Using Zamak 2 with 0.1% Mg die casters produces exceptional aircraft brackets and satellite housings.

These metals prevent creep, maintaining their actual shape under full stress. Also, their low density (6.6 g/cm³) helps in reducing part weight and gives structural integrity.

3.   Construction: Durable Hardware for Everyday Use

The Zamak 3 option works well for making different door handle designs, locks and roof fittings. They allow you to cast them easily for making deeply complex shapes at cost-effective prices.

Moreover, Zamak 3 resists corrosion excellently. That is why they can be used for outdoor applications, too.

4.   Consumer Goods: Stylish and Strong Designs

Manufacturers use Zamak 5 to make appliance gears, furniture hinges, and decorative trims. Using these alloys in the HDPC process can improve the output quality and their surface finishing.

These parts can retain fine details. Also, in regard to aesthetic parameters, zinc creates beautiful appearances and functions well.

Challenges and Future Directions

Temperature Limits in Die Casting

Zinc alloys melt very fast, usually around 385–430°C. This becomes the reason for not using them in high-temperature applications above 150°C.

Furthermore, they can stick to mold surfaces, and cause die wear under high die-casting temperatures.

At this point, you can apply coating on dies or use better cooling systems to stop these issues.

For example, this graph shows the die temperatures in HPDC for zinc. You can see a preheated die (180°C) quickly reach a stable temperature compared to a cold one (30°C). These temperatures are also impacting cycle times and casting quality.

Oxidation Risks and Solutions

Zinc does not handle higher temperatures; you have discovered this earlier. But what happens when you heat them above 400°C? Basically, zinc produces zinc oxide (ZnO), which weakens the manufacturing.

These emissions can really make a surge in porosity and surface defects. Therefore, you must use argon gas shielding or vacuum die casting. These techniques will remove oxygen during casting and reduce oxidation risks.

Research to Improve Zinc Alloys

Scientists are looking forward to improving zinc alloys capabilities. They are testing their results by adding other earth elements like titanium (Ti), iron (Fe), etc. For example, Zn-Ti alloy can handle higher temperatures better, up to 200°C.

Furthermore, advancements in die-casting machines also help reduce defects with their included function of real-time pressure sensors.

The microstructure of a Zn-1Fe-1Mg alloy in the image shows its various changing aspects. For instance, section (a) reveals as-cast microstructure with labeled phases of Zn, FeZn13, and Mg2Zn11.

Likewise, section (b) indicates a homogenized microstructure containing a better distribution of Mg2Zn11

The C part is showing XRD patterns. This pattern compares the as-cast and homogenized samples. So that to confirm the presence of indicial phases.

Zinc in Emerging Technologies

The manufacturers explore zinc alloy abilities, checking them in electric vehicle. In particular, they make lightweight battery housing and motor parts with them. They discover zinc suitability due to its good electrical conductivity and EMI shielding.

Additionally, integrating additive manufacturing (3D printing) in their HPDC process allows them to create objects successfully by forming layers of materials.

Ongoing Projects

The University of Michigan and automotive companies conduct several studies. They are trying to discover the best functions of zinc-aluminum composites in engine components.

Also, most of the institutes, like the Fraunhofer Institute (Germany), are focusing on high-speed die-casting development. So the production of zinc parts becomes faster than traditional methods.

結論

Zinc alloys in high-pressure die-casting (HPDC) offer numerous benefits. That includes faster production, high strength, good surface finish, accuracy, etc. These alloys use less energy and produce ideal parts for automotive, electronics, and industrial applications.

Because each industry needs some kind of special material. That can provide them with demand-stated parts, durability, and efficiency. Therefore, researchers keep discovering zinc alloys to prove their value.

For zinc alloy high-pressure die casting, Alu Die Casting is one of the reputable die casting companies. We have extensive experience in 亜鉛ダイカスト, have good customer reviews, and certifications like ISO 9001. Our company offers affordable pricing, good lead times, and expertise in the specific zinc alloy. Contact us at info@aludiecasting.com