CuSn6 Phosphor Bronze

Grade Designation & Standards

Standard Grade: CuSn6 (Phosphor Bronze)

International Equivalents:

• UNS (USA): C51900

• EN (Europe): CW453K (CuSn6)

• JIS (Japan): C5191

Applicable Standards:

• GB/T 5231-2012 (Wrought Copper Alloys)

• ASTM B103 (U.S. Strip Standard)

• EN 12163 (European Standard)

Product Features

1. Ultra-High Elasticity & Fatigue Resistance: Elastic limit ≥500 MPa, fatigue life >1 million cycles, ideal for high-frequency elastic components.

2. Exceptional Wear Resistance: Hardness (HV 150-250) surpasses low-tin bronzes, approaching beryllium bronze performance.

3. Superior Corrosion Resistance: Resists atmospheric, seawater, and weak acid corrosion (corrosion rate ≤0.005 mm/a).

4. Precision Machinability: Supports cold/hot working, welding, and plating; surface finish up to Ra 0.2μm.

Common Product Forms & Dimensions

Product Form	Size Range	Delivery Condition
Strip	Thickness: 0.05-2.0mm, Width ≤600mm	Soft (M), Hard (H)
Rod	Diameter: 5-150mm, Length: 2-6m	Drawn, Hot-Rolled
Wire	Diameter: 0.05-8.0mm	Coiled or Straight
Tube	OD: 3-200mm, Wall Thickness: 0.5-20mm	Cold-Drawn, Half-Hard

Chemical Composition

Element	Content (%)	Function/Limit
Cu	Balance (≥93.5%)	Base material, ensures conductivity and corrosion resistance
Sn	5.5-7.0	Enhances elasticity, wear resistance, and corrosion resistance
P	0.1-0.35	Deoxidizer, refines grain structure, prevents tin segregation
Pb	≤0.02	Strictly controlled to avoid brittleness
Impurities	≤0.1	Ensures high material purity

Physical Properties

Property	Value	Remarks
Density	8.8-8.9 g/cm³	High density for precision parts
Electrical Conductivity	~13% IACS	Suitable for electrical components
Thermal Conductivity	60-70 W/(m·K)	Moderate heat dissipation
Thermal Expansion	17.6×10⁻⁶/°C (20-200°C)	Excellent thermal stability
Melting Point	995-1020°C	Limited castability

Mechanical Properties

Property	Soft (M)	Hard (H04)
Tensile Strength (σb)	400-600 MPa	650-850 MPa
Elongation (δ10)	≥35%	≥5%
Hardness (HV)	90-180	200-300
Elastic Modulus	≥115 GPa	Critical for high-end springs

Core Advantages

1. Optimal Performance Balance: Strength, elasticity, and corrosion resistance tailored for precision industrial applications.

2. Long Service Life: Exceptional fatigue resistance (>1 million cycles).

3. Surface Treatment Compatibility: Supports gold/silver plating, passivation, and coatings.

Product Applications

1. Electronics:

5G Devices: RF connector springs, EMI shielding components.

Semiconductor Testing: Probe card springs, chip contact points.

2. Mechanical Engineering:

Aerospace: Hydraulic valve plates, gyroscope springs (high-pressure and fatigue resistance).

Medical Devices: Endoscope springs, surgical tool joints (biocompatibility requirements).

3. Automotive:

High-Pressure Fuel Systems: Precision springs, sealing rings (corrosion and pressure resistance).

4. Marine Engineering:

Deep-Sea Equipment: Seawater-resistant valves, sensor components (longevity in harsh environments).

Processing Guidelines

1. Annealing: Post-cold working, anneal at 650-750°C for 1-2 hours to relieve stress.

2. Welding: Laser or electron beam welding preferred to minimize heat-affected zone brittleness.

3. Machining: Cutting speed ≤50 m/min; use carbide tools with oil-based coolant.

4. Surface Preparation: Clean surfaces thoroughly before plating to ensure coating adhesion.

Key Application Scenarios

• Precision Springs: Medical devices, optical instruments.

• Wear-Resistant Components: Bearings, gears, bushings.

• Corrosion-Resistant Systems: Seawater desalination plants, chemical valves.

FAQs of CuSn6 Material

Q: How does Cu Sn 6 differ from Cu Sn 5?

A: CuSn6 bronze has higher tin content (5.5-7.0% vs. 4.5-5.5%), offering superior elasticity and wear resistance but at a higher cost.

Q: Is CuSn6 suitable for high-temperature environments?

A: Long-term use is recommended ≤150°C; short-term tolerance up to 250°C. Avoid exceeding 300°C to prevent softening.

Q: How to prevent edge cracking during cold rolling?

A: Limit single-pass deformation to ≤15%, perform stress-relief annealing, and ensure smooth roller surfaces.

Standard References

• Chemical Composition: GB/T 5231-2012, ASTM B103.

• Mechanical Testing: EN 12163, JIS H3270 (Rod Standard).

• Processing: ISO 426-2 (International Manufacturing Guidelines).

Note: Data consolidated from national standards and industry technical documents. Actual performance may vary slightly due to manufacturing processes. Always refer to supplier test reports for precise specifications.