Alpha Brass is a copper–zinc alloy containing less than 37% zinc, consisting entirely of the alpha (α) phase. This composition provides excellent ductility, corrosion resistance, and outstanding cold-working capability.
Its gold-like appearance, smooth surface finish, and reliable mechanical performance make alpha brass one of the most widely used brasses in industrial, architectural, and decorative applications.
Chemical Composition
| Element | Content (wt%) |
|---|---|
| Copper (Cu) | 65 – 75 |
| Zinc (Zn) | 25 – 35 |
| Lead (Pb) | ≤ 0.05 |
| Iron (Fe) | ≤ 0.05 |
| Other Impurities | Trace |
Note: Zinc content above ~35% introduces β-phase, transitioning the alloy to alpha–beta (duplex) brass.
Crystal Structure & Metallurgical Nature
Phase: Single α-phase
Crystal Structure: Face-Centered Cubic (FCC)
Solid Solution: Substitutional Zn atoms in Cu lattice
This FCC structure provides high ductility, excellent cold deformation capability, and superior toughness at room temperature.
Physical Properties
| Property | Typical Value |
|---|---|
| Density | 8.4 – 8.6 g/cm³ |
| Melting Range | 900 – 940 °C |
| Electrical Conductivity | 26 – 30% IACS |
| Thermal Conductivity | 120 – 130 W/m·K |
| Thermal Expansion | ~20 × 10⁻⁶ /°C |
| Color | Yellow to golden |
| Magnetic Behavior | Non-magnetic |
| Corrosion Resistance | Excellent |
Mechanical Properties
| Property | Annealed | Cold-Worked |
|---|---|---|
| Tensile Strength | 300 – 350 MPa | 450 – 550 MPa |
| Yield Strength | 100 – 150 MPa | 300 – 450 MPa |
| Elongation | 40 – 60% | 5 – 20% |
| Hardness | 60 – 90 HB | 120 – 160 HB |
| Impact Toughness | High | Moderate |
Strengthening & Metallurgical Behavior
✔ Solid solution strengthening by zinc
✔ Cold work (strain hardening) increases strength
✔ Cannot be hardened by heat treatment
✔ Easily softened by annealing (450–650 °C)
Key Characteristics
✔ Single-phase microstructure
✔ Exceptional cold formability
✔ Smooth surface finish
✔ High corrosion resistance
✔ Non-sparking and non-magnetic
Available Forms
| Form | Description |
|---|---|
| Sheets & Plates | Architectural, electrical |
| Strips & Foils | Precision components |
| Tubes & Pipes | Heat exchangers, plumbing |
| Rods & Bars | Fasteners, fittings |
| Wires | Electrical & decorative |
| Forgings | Valves, couplings |
Applications
Heat exchanger and condenser tubes
Electrical terminals and connectors
Decorative architectural panels
Door handles and fixtures
Radiators, bushings, fuel system parts
Musical instruments, coins, jewelry components
Advantages
✔ Outstanding cold-workability
✔ Excellent corrosion resistance
✔ Attractive appearance
✔ Cost-effective copper alloy
✔ Fully recyclable and sustainable
Why Choose Alpha Brass?
Alpha brass is the best choice for cold-formed components requiring superior surface finish, reliable corrosion resistance, and an ideal balance of strength and ductility.