1. Decoding the Designation

The string “CuAl10Fe5Ni5 + SL4 dot bearing bushes” resolves into a clear engineering specification:

2. Base Material — CuAl10Fe5Ni5 (Nickel-Aluminum Bronze)

Nickel-aluminum bronze is among the copper alloys offering a favorable balance of strength, corrosion resistance (especially in seawater), wear resistance, and high-temperature stability. Multiple elements (Al/Fe/Ni/Mn) jointly strengthen the matrix.

Note: values vary slightly by standard and casting route (continuous GC, centrifugal GZ, sand). As an oilless-bearing matrix, the load ceiling follows GB/T 23894 verification: static load upper limit 250 MPa, dynamic load upper limit 100 MPa.

3. SL4 Solid Lubricant (the “lubricant core” of the dots)

SL is a classification for solid lubricants used in inlaid (JDB-class / 500AB-series) bearings. SL4 differs from ordinary graphite: it is a PTFE-based formulation developed for water / seawater contact.

Key advantage of SL4: a low friction coefficient and good wettability that sustain a stable film in water — the reason it is selected over SL1 graphite for submerged and seawater duty.

4. Dot Structure & Self-Lubrication Mechanism

Lubrication mechanism (why it runs without oil)

1. Run-in: a thin film of compatible grease or water at assembly shortens run-in; friction heat and shear then “activate” SL4.
2. Film transfer: SL4 particles migrate from the pockets, fill the shaft’s微观 valleys, and form a continuous, adherent solid film (1–3 µm).
3. Continuous supply: sliding becomes inter-layer slip of PTFE/graphite; the pocket reservoir replenishes the interface gradually (self-repairing).
4. Metal-contact isolation: metal-on-metal contact is replaced by low-shear solid film slip, avoiding seizure and scoring.

5. Dot Geometry & Fit Design Parameters

Dot size is not arbitrary: it balances lubrication sufficiency against matrix strength (too large → weak bronze web, deformation/dislodging; too small → insufficient supply, scoring).

6. Performance Envelope (GB/T 23894 + Aluminum-Bronze Matrix)

Comparison within the same bearing family: high-tensile brass matrix offers higher hardness (HB>250) and similar dynamic load; tin-bronze matrix gives better corrosion but lower hardness (HB 70–100) and lower dynamic load; aluminum bronze (this topic) offers a favorable balance of strength and seawater resistance.

7. Typical Applications

• Marine / offshore: propeller shafts, seawater pump valves, hull fittings, port machinery, submerged pivots (SL4 is designed for seawater).
• Water engineering: radial/plane gate hinges, lock miter gates, turbine guide bearings — documented cases report 20–40 years of service with minimal maintenance.
• Injection molding machines: toggle linkages, which see 100 MPa+ clamp force; SL4 lowers start-up friction and avoids scoring.
• Wind power: offshore turbine yaw/pitch bearing pads (corrosion resistance, low maintenance).
• Heavy industry / metallurgy: continuous casters, rolling-mill nut assemblies, mining and construction-machine articulation points.
• Construction & earth-moving equipment: boom and linkage pivot bushes exposed to shock, mud, and dust.

8. Standards & Grade Cross-Reference

9. Selection & Procurement Checklist

When to choose “aluminum bronze + SL4 dots”

• Medium is water / seawater / humid / mildly corrosive and lubrication is impractical → choose SL4 (not SL1 graphite).
• Both high load and seawater resistance are required → aluminum bronze outperforms high-tensile brass (less corrosion resistance) and tin bronze (lower load capacity).
• Temperature ≤400 ℃, load ≤100 MPa (dynamic) / 250 MPa (static), PV ≤1.65 (dry).

Parameters to specify when ordering

• Form: straight / flanged / split / thrust washer / slide plate
• Dimensions: ID × OD × length (or flange OD/thickness), tolerance zone (F7/m6, etc.)
• Matrix grade: CuAl10Fe5Ni5 (confirm CC333G/C95500 vs national-standard ZCuAl9Fe4Ni4Mn2)
• Lubricant dots: SL4 (PTFE), coverage 25–35%, hole Ø/depth/pattern (diamond/flower/spiral)
• Duty: medium, temperature, load, speed, PV, motion type (rotation/oscillation/reciprocation)
• Mating shaft: material & hardness (≥HRC 45–50), surface roughness
• Standard: GB/T 23894 / ISO 4379 / customer drawing

10. Supply — VIIPLUS SOLUTIONS ®️

VIIPLUS SOLUTIONS ®️ supplies CuAl10Fe5Ni5 + SL4 self-lubricating bushes and JDB/SPB-class inlaid bearings to DIN 1494 and customer drawings, including sleeves, flanges, washers, thrust plates, and large water-engineering pivot components. The SL solid-lubricant grade system (SL1–SL4) is offered across the product range. Products are selected by certification (e.g., ISO 9001), capacity, and documented project references.

11. Hinge Top / Bottom Bearing Bushes — Application Matrix & Selection

In many of the devices above, bushes are used in paired “upper-hinge + lower-hinge” form: the hinge top bearing bush and the hinge bottom bearing bush are mounted at the upper and lower ends of the hinge structure, serving as the rotary support of the shaft. They are normally coaxial, paired, and of the same matrix and lubricant grade, ensuring reliable long-term operation of the hinge under heavy load, vibration, and corrosion.

11.1 Paired relationship

• Top bush (upper hinge): at the upper end, often provides axial location and carries the upward load component.
• Bottom bush (lower hinge): at the lower end, often carries the main reaction / dead weight — the primary loaded pivot.
• Both are coaxial, paired, same grade; shaft hardness ≥HRC 45–50, housing H7, coaxiality ≤0.04 mm (grade 8); screw-fix to prevent rotation under heavy oscillating load.

11.2 Application-location matrix (top / bottom bush × equipment)

11.3 Material-selection guidance for top / bottom bushes

• Matrix priority: corrosion + load together → CuAl10Fe5Ni5; dry heavy load, low corrosion → high-tensile brass matrix (e.g., CuZn25Al5Mn4Fe3); strong corrosion, lower load → tin-bronze matrix (e.g., CuSn10P1).
• Lubricant grade: water / seawater / clean water → SL4; dry / high temperature → SL1; heavy sediment → coverage ≥30% + SL4.
• Form: top/bottom pivots often need flanged type for axial location; very large diameters (lock pintles) may use segmented (4–8 piece) design for replaceability.
• Pairing rule: upper and lower bushes must share matrix & grade, coaxiality ≤0.04 mm, to avoid uneven load and early failure; screw-fix under oscillating heavy load.
• Specification: use the Section 9 checklist and additionally state “top/bottom paired, flanged, coaxiality requirement.”

12. Conclusion (TL;DR)

Note: SL4, JDB, and “dot” are vendor / industry terms; formulations and spec sheets vary by supplier. Always confirm with the selected supplier’s technical documentation.

Disclaimer

• This document is for engineering reference only. It is not a product warranty, certification, or compliance statement.
• Performance values are typical / representative figures compiled from public literature, national standards, and industry articles. Actual values depend on casting route, formulation, and duty; verify against the selected supplier’s specification sheet before design or procurement.
• Brand names and specific company references have been removed; remaining grade codes (SL1/SL4, JDB, 500AB, CuAl10Fe5Ni5, CC333G, C95500) are generic industry/standards terminology.