BZn12-26 Copper

Designation and Standards

• Standard Designation: BZn12-26 (Nickel Silver)

• Applicable Standard: GB/T 5231-2012 (Wrought Copper and Copper Alloys)

• International Equivalent Grades: ASTM C75720, JIS C7452

• Material Category: Copper-Nickel-Zinc Ternary Alloy (Cu-Ni-Zn), containing 59.0%-62.0% Copper, 11.0%-13.0% Nickel + Cobalt, with the remainder being zinc (approximately 25%-30%).

Product Characteristics

1. Balance of High Strength and Corrosion Resistance:

Tensile strength ≥ 380 MPa (annealed), up to 650 MPa (hardened). Excellent seawater corrosion resistance (corrosion rate ≤ 0.008 mm/a).

2. Excellent Processing Performance:

Good cold and hot working performance, supporting processes such as deep drawing, stretching, and electroplating, with a surface finish of up to Ra 0.4 μm.

3. Outstanding Electromagnetic Shielding:

Electrical conductivity ≥ 6% IACS, with electromagnetic shielding effectiveness (SE ≥ 60 dB @ 1 GHz), making it suitable for precision electronic enclosures.

4. Environmental Compatibility:

Lead content ≤ 0.03%, in compliance with RoHS directive requirements.

Chemical Composition

Element	Cu	Ni+Co	Zn	Fe	Mn	Total Impurities
Content (%)	59.0-62.0	11.0-13.0	Remainder (approximately 25%-30%)	≤0.3	≤0.5	≤0.8

Physical Properties

Performance Parameters	Values	Remarks
Density	8.65 g/cm³	Advantages of Lightweight Design
Electrical conductivity	6%-8% IACS	Meets General Requirements for Electrical Conductivity and Shielding
Thermal Conductivity	38 W/(m·K)	Moderate Heat Dissipation Capability
Coefficient of Linear Expansion	16.5×10⁻⁶/℃（20-300℃）	Excellent Thermal Stability
Magnetism	Weak Magnetism (μr ≈ 1.02)	Suitable for Applications in Non-Magnetic Environments

Mechanical Properties

Performance Parameters	Annealed (M)	Hardened (H04)
Tensile Strength (σb)	≥380 MPa	600-750 MPa
Elongation Rate (δ10)	≥20%	≥3%
Vickers Hardness (HV)	≤120	180-220
Elastic Modulus	130 GPa	Material Rigidity Index

Core Advantages

• Corrosion Resistance: 30%-50% lower corrosion rate than brass in seawater, humid atmospheres, and weak acids.

• Surface Treatment Adaptability: Supports various surface treatments such as nickel plating, gold plating and passivation, enhancing both functionality and aesthetics.

• High Cost-Performance Ratio: 40%-60% lower cost than pure nickel alloys, ideal for large-scale industrial applications.

Application Fields

1. Electronics Industry:

5G Communication Equipment: RF connector housings and base station shielding covers (EMI shielding and weather resistance).

Consumer Electronics: High-end headphone jacks and smart watch casings (surface plating compatibility).

2. Marine Engineering:

Seawater Desalination Equipment: Valve components and pump body liners (resistance to chloride ion corrosion).

3. Precision Machinery:

Optical Instruments: Lens mounts and precision gears (dimensional stability and wear resistance).

4. Automotive Industry:

New Energy Vehicles: Charging interfaces and battery connection pieces (balance of conductivity and corrosion resistance).

Processing Precautions

• Annealing Process: After cold working, anneal at 650-750℃ for 1-2 hours to restore plasticity.

• Cutting Parameters: Cutting speed should not exceed 50 m/min, using carbide tools, and the coolant must contain anti-adhesion additives.

• Welding Requirements: It is preferable to use laser welding or electron beam welding to avoid grain boundary corrosion associated with traditional welding methods.

• Electroplating Process: The thickness of the pre-plated nickel layer should be ≥ 3μm to ensure the adhesion of subsequent gold/silver layers.

Frequently Asked Questions

Q: What are the differences between BZn12-26 and BZn12-24?

A: BZn12-26 has a higher zinc content (25%-30% vs. 21%-26%), offers slightly better strength and corrosion resistance, but has lower electrical conductivity (6%-8% vs. 7% IACS).

Q: Is it suitable for high-temperature environments?

A: The recommended long-term operating temperature is ≤150℃, while it can tolerate short-term exposure up to 250℃; temperatures exceeding 300℃ will significantly soften the material.

Q: How can the yield of stamping forming be optimized?

A: Control the mold gap to be 8%-12% of the material thickness, maintain a stamping speed of ≤30 strokes per minute, and apply a lubricant (such as a PTFE coating) after annealing.

Standard References

• Chemical Composition and Processing Specifications: GB/T 5231-2012, ASTM B122 (American Standard for Plates).

• International Standards: JIS H3130 (Japanese Standard), ISO 426-2 (International General Standard).

Note: The data above is compiled from national standards and industry technical documents; actual performance may vary slightly due to production processes, and specific results should be based on the supplier's test report.