Die-casting zinc alloys are specialized zinc-based materials designed for high-precision, high-volume casting using pressure die-casting technology. These alloys—commonly known as Zamak (Zinc-Aluminium-Magnesium-Copper) series—offer excellent castability, dimensional accuracy, strength, and surface finish.
They are widely used for producing complex, detailed components with tight tolerances, making them the preferred choice for automotive, electrical, hardware, and consumer-product industries.
Zinc die-casting alloys solidify quickly, allowing manufacturers to achieve high production rates, smooth surfaces, and minimal post-processing.
Chemical Composition
Typical ZAMAK Alloy Composition (Example Range)
| Element | Typical Content |
|---|---|
| Zinc (Zn) | 95–96% |
| Aluminum (Al) | 3.5–4.3% |
| Magnesium (Mg) | 0.02–0.06% |
| Copper (Cu) | 0–3% (varies by grade) |
| Iron / Lead / Cadmium | Trace (strictly controlled) |
ZA Alloys
Higher aluminum content (8–27%)
Offer increased strength and wear resistance
Electrolytic zinc (SHG) is always used as the base metal to ensure impurity control and casting stability.
Key Mechanical Properties
Zinc die-casting alloys provide exceptional strength for a low-melting non-ferrous metal.
Typical Mechanical Properties
| Property | Typical Value |
|---|---|
| Tensile Strength | 280–320 MPa |
| Yield Strength | 200–230 MPa |
| Elongation | 7–12% |
| Hardness | 80–90 HB |
| Impact Strength | Moderate |
| Fatigue Resistance | Good |
ZA Alloys
Tensile strength up to 400 MPa
Higher hardness and wear resistance
Slightly reduced ductility
Physical Properties
| Property | Typical Value |
|---|---|
| Density | 6.6–6.9 g/cm³ |
| Melting Range | 380–390°C |
| Thermal Conductivity | ~110 W/m·K |
| Electrical Conductivity | ~27% IACS |
| Coefficient of Thermal Expansion | 26–28 µm/m·°C |
| Casting Shrinkage | Very low |
| Crystal Structure | FCC (modified by alloying) |
Strengthening & Metallurgical Behavior
Microstructural Characteristics
Fine, uniform dendritic microstructure
Aluminum forms a strengthening solid solution
Copper improves hardness and wear resistance
Magnesium controls grain growth and oxidation
Strengthening Mechanisms
Solid-solution strengthening (Al in Zn matrix)
Intermetallic phase formation (Zn-Al, Zn-Cu)
Grain refinement during rapid die solidification
Zinc die-casting alloys do not require heat treatment—full mechanical strength is achieved directly after casting.
Key Characteristics
1. Outstanding Castability
Excellent molten metal fluidity
Fills thin sections (<0.5 mm)
Minimal porosity when properly processed
2. High Dimensional Accuracy
Tight tolerances
Minimal post-machining
Excellent repeatability in mass production
3. Superior Surface Finish
Smooth, defect-free surfaces
Ideal for:
Electroplating
Powder coating
Painting
Polishing
4. Low Melting & Long Die Life
Low thermal stress on molds
Significantly longer die life than aluminum die casting
Refining & Processing Properties
Refining & Alloy Preparation
Electrolytic zinc melted under controlled conditions
Precise alloying with aluminum, copper, magnesium
Strict impurity control (Pb, Cd, Fe)
Die-Casting Processing Advantages
Low melting temperature → energy efficient
Fast cycle times
Excellent mold filling
High production rates
Secondary Operations
Drilling
Tapping
Thread rolling
Surface finishing
Available Forms
Die-casting zinc alloys are supplied as:
ZAMAK ingots
ZA alloy ingots
Jumbo blocks
Pre-alloyed casting pigs
Custom alloy compositions (OEM specific)
Applications of Die-Casting Zinc Alloys
1. Automotive Industry
Door handles
Locks & latches
Brackets
Emblems
2. Electrical & Electronics
Housings
Connectors
Switch components
EMI shielding parts
3. Hardware & Construction
Hinges
Fasteners
Knobs
Architectural fittings
4. Consumer Products
Appliances
Tools
Zippers
Decorative components
5. Industrial Machinery
Precision housings
Wear-resistant parts
Bearing components (ZA alloys)
Advantages of Die-Casting Zinc Alloys
✔ Excellent strength-to-weight ratio
✔ Superior surface finish
✔ Exceptional dimensional precision
✔ Low energy processing
✔ Long mold life
✔ Cost-effective for high-volume production
✔ Fully recyclable
Limitations
❌ Not suitable for high-temperature service (>120°C continuous)
❌ Lower stiffness than steel
❌ Heavier than aluminum
❌ Not ideal for large structural components
Why Choose Die-Casting Zinc Alloys?
Die-casting zinc alloys are chosen when precision, surface quality, strength, and production efficiency are critical.
Manufacturers choose zinc die casting because it:
Reduces machining and finishing costs
Enables complex, thin-wall designs
Delivers consistent quality at scale
Shortens production cycles
Offers excellent cost-to-performance balance
Die-casting zinc alloys represent one of the most efficient and versatile casting materials in modern manufacturing. With excellent castability, high mechanical strength, fine surface finish, and exceptional dimensional control, they are ideal for mass-produced precision components across automotive, electrical, construction, and consumer sectors.
Their ability to deliver net-shape parts at low energy cost makes them a preferred choice wherever quality, speed, and economics intersect.