Bismuth bronze

Bismuth bronze is a versatile alloy with a wide range of applications, primarily due to its lead-free composition, good machinability, and corrosion resistance. Here are some common ways bismuth bronze is used:

Plumbing and Waterworks:

Faucets and fittings: Its lead-free nature makes it ideal for components in contact with drinking water, complying with regulations like the Reduction of Lead in Drinking Water Act.
Valves and pumps: Bismuth bronze’s strength and corrosion resistance ensure reliable performance in water systems.
Pipe fittings: Durable and safe for potable water, bismuth bronze fittings are used in residential and commercial plumbing.
Water pump impellers: The alloy’s resistance to wear and corrosion makes it suitable for pump components.

Industrial Applications:

Bearings and bushings: Bismuth bronze offers good wear resistance and lubricity, making it suitable for bearing applications.
Gears and other machine parts: Its machinability and strength allow for the production of complex parts.
Housings and structural components: Bismuth bronze can be used for structural elements requiring corrosion resistance.

Other Uses:

Decorative items: The alloy’s attractive appearance and ability to hold a polish make it suitable for decorative applications.
Musical instruments: Some musical instrument components may be made from bismuth bronze.
Marine applications: Its corrosion resistance makes it suitable for use in marine environments.

Advantages of Bismuth Bronze:

Lead-free: Environmentally friendly and safe for use in contact with drinking water.
Good machinability: Easy to machine into complex shapes.
Corrosion resistance: Suitable for use in harsh environments.
Good wear resistance: Offers durability in moving parts.
Attractive appearance: Can be polished to a high sheen.

Overall, bismuth bronze is a versatile material with a wide range of applications, particularly in plumbing and industrial sectors where its lead-free composition and performance characteristics are valued.

Key properties:

Lead-free
Good machinability (70% compared to free-cutting brass)
Good polishing and plating characteristics
Better castability at lower temperatures
Superior microstructural characteristics

Applications:

Faucets
Housings
Small gears
Pipe fittings
Plumbing goods
Pump components
Water pump impellers

Chemical composition:

Copper (Cu): 85.0 – 89.0%
Tin (Sn): 6.0 – 7.5%
Lead (Pb): 0.09% max
Zinc (Zn): 2.0 – 4.0%
Iron (Fe): 0.20% max
Nickel (Ni): 1.00% max
Antimony (Sb): 0.35% max
Phosphorus (P): 0.10% max
Sulfur (S): 0.08% max
Aluminum (Al): 0.005% max
Bismuth (Bi): 1.7 – 2.7%
Silicon (Si): 0.005% max

Mechanical properties:

Tensile strength: 30 ksi (207 MPa) min
Yield strength: 14 ksi (97 MPa) min
Elongation in 2 in. or 50 mm: 6% min

Physical properties:

Melting point – liquidus: 1855°F (1012°C)
Melting point – solidus: 1445°F (785°C)
Density: 0.321 lb/in3 at 68°F (8.89 gm/cm3 at 20°C)
Specific gravity: 8.89
Electrical conductivity: 14.5% IACS at 68°F (0.084 MegaSiemens/cm at 20°C)
Thermal conductivity: 38.0 Btu·ft/(hr·ft2·°F) at 68°F (65.8 W/m·°K at 20°C)
Coefficient of thermal expansion: 10 x 10-6 per °F (68-392°F) (17.3 x 10-6 per °C)
Specific heat capacity: 0.093 Btu/lb/°F at 68°F (389.6 J/kg·°K at 293°K)
Modulus of elasticity in tension: 16,900 ksi (116,522 MPa)