ZCuAl10Fe5Ni5 Aluminum Bronze Inlaid with PTFE Bearings: Self-Lubricating Bearings Resistant to Salt Spray and Seawater Corrosion

ZCuAl10Fe5Ni5 is a high-strength, highly corrosion-resistant aluminum bronze alloy widely used in extreme corrosion environments such as marine engineering, ships, seawater desalination, and chemical equipment. Mingxu Machinery utilizes this alloy as the base material and inlays it with polytetrafluoroethylene (PTFE) composite lubricating columns, creating a high-performance sliding bearing or bushing that combines exceptional corrosion resistance, excellent load-bearing capacity, and long-lasting self-lubricating properties. It is suitable for applications involving high salt spray, long-term immersion in seawater, and maintenance-free operation.

Mingxu Machinery systematically analyzes the technical advantages and engineering applicability of this composite structure from salt spray resistance, seawater corrosion resistance, and self-lubricating performance.

1. Material Composition and Structural Overview

• Base Material: ZCuAl10Fe5Ni5
• National Standard Grade: GB/T 1176-2013 Cast Copper and Copper Alloys
• Composition: Approx. 10% Al, 5% Fe, 5% Ni, balance Cu
• Key Characteristics: High strength, high hardness, excellent electrochemical corrosion resistance

• Lubricating Components: PTFE composite lubricating columns
• Material: Modified PTFE
• Function: Continuous self-lubrication, reduced friction coefficient, dry-friction seizure prevention
• Structure: Holes drilled on the bronze matrix with ≤30% surface coverage, PTFE columns pressed-in, forming “metal load-bearing + solid lubrication” configuration

2. Salt Spray Resistance

Performance: Excellent

ZCuAl10Fe5Ni5 exhibits significantly higher salt spray resistance than tin bronzes and brasses.

Test Standard: GB/T 10125-2021 / ISO 9227 (NSS)

Result: No red rust or pitting after 1000+ hours; oxide film remains compact and stable.

Mechanism

• Dense Al₂O₃ + NiO oxide film blocks Cl⁻ penetration
• Low galvanic corrosion tendency
• Fe and Ni refine grains and enhance corrosion uniformity

Applicable for coastal power plants, offshore platforms, and ships without additional coating.

3. Seawater Corrosion Resistance

Performance: Outstanding

• Uniform corrosion rate: < 0.025 mm/year
• Low pitting and crevice corrosion sensitivity (≤3 m/s flow)
• Excellent erosion-corrosion resistance
• Copper ions inhibit microbial growth

Engineering Cases

• Ship rudder bearings operating 8+ years in South China & East China Sea
• Desalination pumps tolerating up to 19,000 ppm Cl⁻
• Offshore lifting mechanisms exposed to tidal cycling without corrosion

Suitable for long-term seawater immersion and tidal zone use.

4. Self-Lubricating Performance

Performance: Efficient, durable, low friction

• Friction coefficient: 0.04–0.12 (as low as 0.06 in water)
• Very low starting torque
• PV limit: 2.5–3.5 MPa·m/s
• Short-term dry running capability
• Service life: 5–10 years

Working Mechanism

• Initial PTFE transfer film formation
• Water + PTFE emulsified lubrication under seawater flushing
• Copper base dissipates heat, protecting PTFE
• Continuous self-supply as columns wear

Precautions

• Avoid temperatures >260°C to prevent PTFE degradation
• Use filtration in sandy seawater to limit abrasive wear

5. Typical Application Scenarios

• Shipbuilding: rudder pins, propeller supports, anchor winch hinges
• Offshore platforms: winch bearings, lifting bushings
• Desalination equipment: high-pressure pump bushings
• Offshore wind power: pitch and yaw sliding pivots
• Port machinery: gantry cranes and guide pulleys

6. Standards and Testing

Material Standards:

• GB/T 1176-2013 Cast Copper and Copper Alloys
• ASTM B505 / B508 Aluminum Bronze

Corrosion Testing:

• GB/T 10125-2021 Salt Spray Test
• GB/T 17848-1999 Seawater Corrosion Method

Friction Testing:

• GB/T 3960-2016 Sliding Friction Test
• M200 PV test reference

7. Summary

The ZCuAl10Fe5Ni5 + PTFE composite bearings from Zhejiang Mingxu demonstrate top-tier performance for extreme marine and corrosive environments:

• 1000+ hours salt spray resistance
• Superior seawater corrosion and erosion resistance
• Ultra-low friction and reliable long-term self-lubrication

Zhejiang Mingxu Machinery Manufacturing Co., Ltd. specializes in copper alloy and self-lubricating bearings with extensive engineering experience. For inquiries, contact: [email protected]