Introduction to C61400 Aluminum Bronze
C61400 is a wrought aluminum bronze in which aluminum is the principal alloying addition and iron is the supporting one, with copper forming the balance. The aluminum content makes the alloy considerably stronger and harder than unalloyed copper, while the presence of iron refines the cast structure and improves resistance to wear and to impingement by fast flowing water.
Because it combines the thermal and electrical conductivity of a copper base with the strength and surface stability of an aluminum bronze, C61400 is found wherever a component must carry load, resist sliding wear and survive a wet or mildly aggressive environment at the same time. Tubes, bars, plates, strip and wire are all produced in the grade, so a single alloy family can serve an entire assembly.
Chemical Composition and Governing Standards
| Element | Symbol | Specified range | Role |
|---|---|---|---|
| Copper | Cu | Balance | Matrix of the alloy |
| Aluminum | Al | 6.0 to 8.5 percent | Principal addition; strength, hardness, oxide film |
| Iron | Fe | 1.5 to 3.5 percent | Grain refinement, wear and impingement resistance |
| Nickel | Ni | 0.6 percent maximum | Optional residual, improves corrosion resistance |
| Manganese | Mn | 1.0 percent maximum | Deoxidation and residual control |
| Zinc | Zn | 0.50 percent maximum | Impurity limit |
| Lead | Pb | 0.02 percent maximum | Impurity limit |
| Tin | Sn | 0.20 percent maximum | Impurity limit |
| Silicon | Si | 0.10 percent maximum | Impurity limit |
| Other impurities | - | 0.50 percent maximum total | Combined residual control |
The grade is ordered against ASTM product specifications according to the form required: ASTM B111/B111M for seamless condenser tube and ferrule stock, ASTM B150/B150M for rod, bar and shapes, and the corresponding ASTM flat-rolled specification where plate, sheet or strip is supplied. Where components are built to the ASME code the same tube is ordered as SB111. In the Chinese system the designation framework is set out in GB/T 5231 for wrought copper and copper alloys, and European buyers commonly work to EN 12449 for seamless tube or EN 12163 and EN 12167 for bar and profile.
Property Profile
Strength and hardness. Aluminum in solid solution, together with iron-rich phases, raises tensile and yield strength substantially above pure copper and gives a hardness level that resists abrasion, galling and erosion in sliding and impinging contact.
Corrosion resistance. The alloy develops a tenacious aluminum oxide film that protects the surface in seawater, in many neutral and mildly acidic solutions and in oxidizing conditions. It is this film, rather than the bulk composition, that determines service life, so anything that destroys it locally, such as deposits, crevices or excessive flow, shortens life.
Wear and fatigue resistance. C61400 is used for bushes, wear plates and guides because it withstands load with low wear against hardened counterfaces, and its fatigue strength is adequate for components subject to cyclic loading in wet service.
Conductivity. Thermal and electrical conductivity are lower than those of pure copper, since the alloying additions scatter heat and charge carriers, but they remain high enough for heat transfer components and for many current-carrying parts.
Low temperature behaviour. The alloy retains useful strength and toughness at low ambient temperatures, which supports its use in cold climate and refrigerated service; it does not show the ductile to brittle transition that limits ferritic steels.
Product Forms and Size Range
| Form | Typical capability |
|---|---|
| Bar and rod | Diameter 1 mm to 800 mm in round, flat, square, hexagonal or rectangular section |
| Tube and pipe | Outside diameter 2 mm to 914 mm, wall thickness 0.2 mm to 120 mm, seamless or welded |
| Plate, sheet and strip | Thickness 0.1 mm to 120 mm, width 2 mm to 2500 mm |
| Wire | Drawn round, square or profile wire with diameter and coil weight to order |
| Temper | Soft, quarter hard, half hard, three-quarter hard and full hard, selected to suit the forming operation |
Applications
Marine fittings, offshore structures and components exposed to seawater spray and immersion.
Corrosion-resistant valves, pump bodies, impellers, pipework and fittings in chemical plant.
Heat exchanger and condenser tubes where heat transfer and durability must be combined.
Bearings, bushes, gears, slides and wear plates in general and heavy machinery.
Electrical connectors, switchgear parts and current-carrying components that also need strength.
Processing, Fabrication and Inspection
C61400 is readily cast, extruded, forged, rolled and drawn, and it machines with conventional copper alloy tooling at moderate cutting speeds with generous coolant. Hot working is carried out in the temperature range recommended for aluminum bronze, followed by controlled cooling; cold forming requires intermediate annealing because the alloy work hardens rapidly. Brazing and gas-shielded arc welding are the usual joining methods, and both depend on clean surfaces, low heat input and correct filler selection to avoid porosity and preferential corrosion alongside the joint.
Verification normally includes chemical analysis of the heat, tension testing in the ordered temper, dimensional inspection against the product standard, and for tube either a pressure test or an electric non-destructive examination. Certificates can be issued to EN 10204 type 3.1, and the material is packed for sea transport with anti-rust protection, wrapping, strapping and protected pallets so that the protective film survives the journey intact.
FAQ
Q: What is C61400 aluminum bronze used for?
It is used for marine fittings, chemical plant components, heat exchanger tubes, bearings and wear parts, and electrical hardware where strength, wear resistance and corrosion resistance must be combined.
Q: What is the aluminum content of C61400?
The specified range is 6.0 to 8.5 percent aluminum, balanced by iron at 1.5 to 3.5 percent, with copper making up the remainder.
Q: Is C61400 the same as the five percent aluminum bronze?
No. C61400 sits at a higher aluminum and iron level than the five percent grade and therefore offers higher strength and wear resistance with slightly lower conductivity.
Q: Which standards apply to C61400?
ASTM B111/B111M applies to seamless tube, ASTM B150/B150M to rod, bar and shapes, SB111 for ASME code work, EN 12449 or EN 12163 for European orders and GB/T 5231 for Chinese designations.
Q: Can C61400 be welded in the field?
Yes, with a controlled procedure. Clean joint faces, low heat input and correct filler selection are essential, and the weld area should be cleaned afterwards to restore the protective film.
Q: How is the alloy supplied in terms of temper?
Temper is chosen for the forming operation, from soft annealed through quarter, half and full hard, and the ordered temper defines the mechanical property requirements on the certificate.
