Zinc alloy and aluminum alloy difference are reflected in the composition, processing, mechanical properties and application areas.

Zinc alloys and aluminum alloys are the two most widely used materials in the die casting industry. They differ significantly in composition, melting point, mechanical properties, and applications. Understanding these differences helps manufacturers select the right material for their product requirements. Misapplication of either alloy can lead to premature part failure or unnecessary production costs.

This article compares zinc alloys and aluminum alloys in terms of composition, melting point, mechanical properties, and applications. It also provides product examples to illustrate the suitable scenarios for each material. Key selection factors include mechanical load, operating temperature, required surface finish, and annual production volume.

As a die casting machine manufacturer, HAICHEN equipment supports both zinc and aluminum alloy production. HAICHEN’s machine range covers clamping forces from 30 to 3,000 tons, allowing optimal matching for both alloy families.

Zinc alloy and aluminum alloy difference

Aluminum alloys and zinc alloys are widely used in a wide range of industries due to their unique properties and characteristics. Here are some of the main differences between aluminum alloy and zinc alloy.

• Compositional differences
• Melting point and processing
• Mechanical properties
• Application Areas

Compositional differences:

• Zinc alloys are mainly based on zinc with other elements such as aluminum, magnesium, copper, cadmium, lead and titanium added as low temperature zinc alloy elements.

• These added elements increase the strength and hardness of the alloy.

• Aluminum alloys, on the other hand, are based on aluminum as the main component. And it usually add elements such as copper, silicon, magnesium, and manganese.

• It help to improve the strength, corrosion resistance, and electrical conductivity of the alloy.

Melting point and processing:

• Zinc alloys have a lower melting point, usually above 400 degrees, and therefore require lower temperatures and pressures during casting. Which gives them good fluidity and makes them easy to weld and plasticize.
• Aluminum alloys have a higher melting point, usually requiring more than 700 degrees Celsius. And therefore require the use of more sophisticated equipment and higher temperatures during casting.

Mechanical properties:

• Zinc alloys typically have a hardness between 65-140 and a tensile strength of 260-440 N/mm², with a higher overall hardness and tensile strength than aluminum alloys.
• Aluminum alloys have a lower hardness, usually between 45-90, and a tensile strength of 120-290 N/mm². Despite their lower strength, aluminum alloys have higher plasticity and specific strength, making them suitable for medium structural materials that carry large weights.

Application Areas:

• Zinc alloys are commonly used in the manufacture of complex shaped parts, such as die-casting molds and automotive parts, due to their low melting point and good casting properties.

• In addition, zinc alloy also has good corrosion resistance and oxidation resistance, suitable for applications under atmospheric environment.

• Aluminum alloy, on the other hand, is widely used in aviation, aerospace, automotive manufacturing, machinery manufacturing and other fields, favored for its high strength, light weight and good electrical conductivity.

Product Examples: Zinc Alloy vs. Aluminum Alloy

Example 1: Zinc Alloy Door Handle

A hardware manufacturer needed to produce European-style door handles with uneven wall thickness (minimum 1.2mm) and complex decorative patterns requiring smooth surface finish.

• Material: Zamak 3 zinc alloy
• Reason: Good fluidity fills thin walls and fine patterns; low melting point extends mold life; excellent surface treatment compatibility
• Parameters: HAICHEN HCD90 hot chamber machine, injection pressure 12MPa, temperature 420℃, two-cavity mold, cycle time 28 seconds
• Result: Clear patterns, smooth surface, annual output over 2 million pieces

Example 2: Aluminum Alloy Engine Mount

An automotive parts supplier needed engine mounts capable of withstanding vibration loads and high temperatures, requiring high strength and light weight.

• Material: A380 aluminum alloy
• Reason: High strength and heat resistance; 30% lighter than zinc alloy; suitable for structural components
• Parameters: HAICHEN HDC600 cold chamber machine, injection pressure 85MPa, temperature 660℃, single-cavity mold, cycle time 95 seconds
• Result: Dense casting without porosity, tensile strength 320MPa, passed durability tests.

Zinc Alloy Lock Housing

• A security hardware manufacturer required a lock housing with complex internal ribs, precise keyway dimensions, and a chrome-plated exterior.
• Material: Zamak 5 zinc alloy
• Reason: Zamak 5 offers higher hardness and creep resistance than Zamak 3, essential for locking mechanisms under repeated torque. Excellent electroplating adhesion provides a decorative finish.
• Parameters: HAICHEN HCD160 hot chamber machine, injection pressure 14MPa, temperature 425℃, four-cavity mold, cycle time 22 seconds
• Result: Consistent keyway tolerance within ±0.02mm, plated surface passed 96-hour salt spray test, annual output 800,000 units.

Aluminum Alloy LED Heat Sink

• A lighting manufacturer needed a heat sink for a 100W LED streetlight. The part required high thermal conductivity, lightweight, and fine fin spacing (1.2mm thick, 8mm height).
• Material: A380 aluminum alloy
• Reason: Aluminum’s thermal conductivity (96‑120 W/m·K) dissipates heat efficiently; die casting produces thin fins without secondary machining.
• Parameters: HAICHEN HDC500 cold chamber machine, injection pressure 90MPa, temperature 670℃, single-cavity mold, cycle time 48 seconds
• Result: Junction temperature maintained below 75°C at 25°C ambient, weight 320g (40% lighter than copper equivalent), passed 10,000-hour life test.

How to Choose Between Zinc Alloy and Aluminum Alloy

• Product Function: Choose aluminum alloy for load-bearing or high-temperature parts. Choose zinc alloy for decorative parts or thin-wall complex shapes.
• Surface Treatment: Zinc alloy suits electroplating applications. Aluminum alloy suits anodizing or painting.
• Production Volume and Cost: Zinc alloy has longer mold life and suits high-volume production. Aluminum alloy has lower per-part cost but higher mold cost, suitable for medium volumes or performance-critical parts.
• Equipment Matching: HAICHEN hot chamber machines suit zinc alloy production. Cold chamber machines suit aluminum alloy production. Equipment selection should match material requirements.

Cost and Lifecycle Considerations for Zinc vs. Aluminum Alloys

While zinc alloys have higher raw material cost per kilogram (approximately 2.5‑3.2/kgvs.2.5‑3.2/kgvs.1.8‑2.5/kg for aluminum), their lower melting point reduces energy consumption by 30‑40% per shot. Zinc also allows thinner walls (0.3‑0.8mm) compared to aluminum (0.8‑1.5mm), saving material weight in small components. For production volumes above 500,000 pieces per year, zinc’s longer mold life (typically 800,000‑2 million shots) often offsets higher alloy cost. Conversely, aluminum becomes more economical for parts weighing over 300g or requiring heat treatment. HAICHEN provides total cost of ownership calculators that compare energy, tooling, and material costs across both alloys based on the customer’s specific part geometry and annual volume.

Haichen die casting machine supplier

Zinc alloys and aluminum alloys each have their advantages and disadvantages, and the choice of which alloy to use depends on the specific needs of the application and the working environment.

Haichen Machinery, a die casting machine supplier. We mainly supply cold chamber and hot chamber die casting machines. Our die casting machines are capable of casting all kinds of zinc alloys, aluminum alloys and various alloys. In addition, we also supply die casting auxiliary machines, welcome to contact us.