Introduction
This article explains the key features and composition of aluminum bronze C61400. Aluminum bronze alloys in the C61300 and C61400 range are copper-aluminum alloys with iron additions that combine high strength with excellent corrosion resistance. They serve marine hardware, heavy-duty bearings, valve components and structural parts where ordinary copper alloys are not strong enough.
Composition
C61300 contains 88.5 to 91.5 percent copper with 6.0 to 7.5 percent aluminum, 2.0 to 3.0 percent iron and small tin and nickel additions, while C61400 carries 88.0 to 92.5 percent copper with 6.0 to 8.0 percent aluminum and 1.5 to 3.5 percent iron. The aluminum provides strength and passive film formation, and the iron refines the grain structure and further improves strength.
Properties
Aluminum bronze reaches tensile strengths from about 480 MPa annealed to over 600 MPa in worked tempers, with good ductility and toughness. It forms a protective aluminum-oxide film that resists seawater, acids and erosion, and it has outstanding resistance to cavitation and impingement attack in high-velocity water service. Thermal conductivity is moderate at roughly 55 to 60 W/(m·K), which must be considered in heat exchange designs.
| Element | C61300 | C61400 |
|---|---|---|
| Copper | 88.5 - 91.5% | 88.0 - 92.5% |
| Aluminum | 6.0 - 7.5% | 6.0 - 8.0% |
| Iron | 2.0 - 3.0% | 1.5 - 3.5% |
| Typical tensile | 480 - 620 MPa | 480 - 600 MPa |
Applications
Typical uses are marine fasteners and hardware, pump shafts and impellers, valve stems, bearings and bushings, wear plates, and structural components for offshore and chemical service. The alloys are covered by standards such as ASTM B150 for rod and bar, B169 for plate and sheet, and B171 for condenser plates.
Selection and Verification
Confirm the aluminum and iron ranges, temper and mechanical properties against the standard, and verify the corrosion test requirements for marine applications. For heavy loaded bearings, specify the hardness and the running clearance with the manufacturer.
