Shenzhen Alu Rapid Prototype Precision Co., Ltd.

The strength of die-cast zinc depends on the alloy, casting process, and any post-processing treatments. Below is a concise overview of its strength characteristics, with comparisons to die-cast aluminum where relevant.

A.Key Factors Affecting Strength

1.Alloy Type: Common die-cast zinc alloys include Zamak 3, Zamak 5, Zamak 7, and ZA-8. Zamak 3 is the most widely used due to its balance of strength, ductility, and castability.

2.Process: High-pressure die casting produces dense, fine-grained parts, enhancing strength. Zinc’s low melting point (~380–420°C) allows for excellent fluidity, filling intricate molds and reducing defects like porosity.

3.Post-Processing: Heat treatments or surface treatments are less common for zinc than aluminum, but plating (e.g., chrome) can improve surface durability.

B.Typical Mechanical Properties

For Zamak 3, a common die-cast zinc alloy:Tensile Strength: 280–330 MPa (41–48 ksi)

Yield Strength: ~200–250 MPa (29–36 ksi)

Elongation: 8–13% (higher ductility than most aluminum alloys)

Hardness: ~80–100 Brinell (HB), comparable to die-cast aluminum

Density: ~6.6 g/cm³ (much denser than aluminum’s ~2.7 g/cm³)

Other alloys:Zamak 5: Slightly higher strength (330–360 MPa tensile) and hardness, with less ductility (7%).

ZA-8: Stronger, with tensile strength up to 370–400 MPa, but less ductile (6–10%).

ZA-27: Can reach ~400–430 MPa but is less common in high-pressure die casting due to higher melting points.

C.Comparison to Die-Cast AluminumStrength: 

Die-cast zinc (e.g., Zamak 3: ~280–330 MPa) is generally weaker than die-cast aluminum (e.g., A380: ~320–350 MPa), but some zinc alloys like ZA-8 approach or match aluminum’s strength.

Ductility: Zinc alloys are more ductile (higher elongation, ~8–13% vs. aluminum’s ~2–4%), making them less brittle and better for parts requiring some flexibility.

Weight: Zinc is ~2.4x denser than aluminum, so aluminum offers a better strength-to-weight ratio, critical for lightweight applications (e.g., automotive, aerospace).

Fatigue and Toughness: Zinc has better impact resistance and fatigue performance due to its ductility, but aluminum is preferred for high-temperature or corrosion-prone environments.

Cost and Castability: Zinc’s lower melting point reduces energy costs and die wear, and it excels in thin-walled, intricate parts with tighter tolerances than aluminum.