Alloy Specifications, Processes & Application Reference
Copper (Cu) is a primary base element for bronze, brass, and other performance bearing alloys. While pure copper is generally too soft to be used directly, its efficient thermal conductivity and reliable corrosion resistance make it a suitable carrier for alloying elements that enhance wear resistance.
Rapidly dissipates friction heat, helping to prevent lubricant breakdown and localized hot spots.
Forms a protective patina. Performs reliably in marine and wet environments compared to standard steel.
Good ductility allows bearings to conform to slight shaft misalignments, distributing loads evenly.
| Alloy Type | Composition | Key Properties | VIIPLUS Products |
|---|---|---|---|
| Tin Bronze | Cu + 10-12% Sn | Classic wear resistance, stable load capacity | Cast Bronze (C90300) |
| Phosphor Bronze | Cu + 5-10% Sn + P | Good fatigue and spring properties | Wrapped Bronze (CuSn8) |
| Lead Bronze | Cu + Sn + Pb | Reliable embeddability, anti-seizure | Bimetal / SAE 660 |
| Aluminum Bronze | Cu + 9-14% Al | Seawater resistant, high strength | VIIPLUS-820 / C95400 |
| Manganese Bronze | Cu + Zn + Al/Mn | Impact resistant, high structural strength | Graphite Plugged (C86300) |
Lead (Pb) traditionally improves machinability. To meet modern RoHS requirements, VIIPLUS offers lead-free alternatives:
Lead (Pb) acts as a built-in solid lubricant, providing reliable anti-galling properties and good machinability.
Forms a protective oxide layer. Offers high resistance to seawater corrosion and structural stability.
A high-strength brass base. Delivers high tensile strength and hardness. Suitable for heavy loads.
Phosphorus (P) deoxidizes and densifies the matrix, providing reliable fatigue resistance.
Tin (Sn) forms δ-phase particles. Provides classic wear resistance and moderate corrosion resistance.
Silicon improves weldability while maintaining dependable corrosion resistance.
Molten bronze cast into shapes. Centrifugal casting ensures consistent material density.
Cold-rolled bronze strip formed into a cylinder with a longitudinal seam.
Powder compacted, sintered, and vacuum-impregnated with oil (15-25% porosity).
Porous bronze layer sintered onto a structural steel backing strip.
| UNS / SAE | Alloy Family | Hardness (HB) | Tensile (MPa) | Typical Applications |
|---|---|---|---|---|
| C93200 (SAE 660) | Leaded Tin Bronze | 65 - 75 | 240 | Excavator booms, hydraulic cylinders, general machinery |
| C52100 (CuSn8) | Phosphor Bronze | 95 | 450 | Thin-wall piston rings, wrapped bushings |
| C95400 | Aluminum Bronze | 170 | 585 | Rudder stocks, winches, marine hardware |
| C95500 | Ni-Aluminum Bronze | 195 | 690 | Wind turbine yaw systems, corrosive environments |
| C86300 | Manganese Bronze | 225 | 795 | Crane swings, roll necks, shock load pivots |
When selecting high-hardness alloys like C86300, the mating steel shaft is generally recommended to be hardened (e.g., HRC 50+). Using a softer shaft may result in accelerated shaft wear.
Sintered Bronze bearings contain 15-25% porosity to hold oil. They are typically not suitable for heavy shock load applications (e.g., excavator main joints) as the porous structure may be compromised.
For potable water systems or RoHS-compliant equipment, consider avoiding C93200 (contains ~7% Lead). Consider lead-free Aluminum Bronze (C95400) or CuSn8Ni as substitutes.