Comparison of C110/T2 and C122/TP2 Copper Standards
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Copper alloys are widely used in industries for their excellent electrical conductivity, thermal conductivity, and corrosion resistance. Two commonly referenced standards, the American ASTM and the Chinese GB, define similar copper grades that are often interchangeable. This article compares C110 (ASTM) with T2 (GB) and C122 (ASTM) with TP2 (GB) to clarify their equivalence and applications.
1. C110 vs. T2 Copper
C110 (also known as C11000 or Electrolytic Tough Pitch copper, ETP) and T2 (per Chinese GB/T 5231-2012) are high-purity copper grades designed for superior electrical and thermal conductivity.
Chemical Composition
| Grade | Standard | Copper (Cu+Ag) | Oxygen | Other Impurities |
|---|---|---|---|---|
| C110 | ASTM B124/B124M | ≥99.90% | ≤0.04% | Minimal |
| T2 | GB/T 5231-2012 | ≥99.90% | ≤0.05% | ≤0.1% total |
Both grades have nearly identical copper purity, with slight variations in oxygen and impurity limits that rarely impact practical use.
Properties and Applications
- Conductivity: Both achieve an IACS (International Annealed Copper Standard) rating of 97-100%, ideal for electrical wiring, busbars, and conductors.
- Thermal Conductivity: Approximately 386.4 W/(m·K), suitable for heat exchangers and radiators.
- Workability: Excellent ductility allows cold and hot forming, welding, and brazing. However, due to trace oxygen, they are susceptible to "hydrogen embrittlement" in high-temperature reducing atmospheres.
- Corrosion Resistance: Outstanding in atmospheric conditions, seawater, and non-oxidizing acids.
Applications: C110/T2 copper is used in electrical cables, connectors, screws, and heat exchanger components in aerospace, electronics, and chemical industries.
Standards Equivalence
C110 (ASTM C11000) directly corresponds to T2 (GB). It also aligns with:
- JIS C1100 (Japan)
- Cu-ETP (CW004A) (European EN standard)
2. C122 vs. TP2 Copper
C122 (C12200, Deoxidized High Phosphorus copper, DHP) and TP2 (GB/T 5231-2012) are phosphorus-deoxidized copper grades with low oxygen content, designed for applications requiring welding and resistance to hydrogen embrittlement.
Chemical Composition
| Grade | Standard | Copper (Cu+Ag) | Phosphorus (P) | Oxygen |
|---|---|---|---|---|
| C122 | ASTM B124/B124M | ≥99.90% | 0.015%-0.040% | Minimal |
| TP2 | GB/T 5231-2012 | ≥99.90% | 0.015%-0.040% | Minimal |
The identical copper and phosphorus content ensures equivalent performance in low-oxygen environments.
Properties and Applications
- Conductivity: Slightly lower than C110/T2 at ~80-85% IACS, but sufficient for many electrical applications.
- Thermal Conductivity: Around 339 W/(m·K), excellent for heat transfer.
- Workability: Superior weldability and formability, with no risk of hydrogen embrittlement in reducing atmospheres.
- Corrosion Resistance: Comparable to C110/T2, ideal for water and gas systems.
Applications: C122/TP2 is preferred for refrigeration tubing, air conditioning coils, plumbing, gas pipelines, and marine systems due to its welding advantages.
Standards Equivalence
C122 (ASTM C12200) directly corresponds to TP2 (GB). It also aligns with:
- JIS C1220 (Japan)
- Cu-DHP (CW024A) (European EN standard)
Key Considerations
- Interchangeability: C110/T2 and C122/TP2 are interchangeable in most applications, but C122/TP2 is preferred for welded components and high-temperature environments.
- Condition: Both grades are available in soft (annealed, e.g., T2M/TP2M, O temper) or hard (e.g., T2Y/TP2Y, H temper) states, selected based on processing needs.
- Specifications: For critical applications (e.g., aerospace or electronics), verify oxygen or impurity limits per ASTM or GB standards.
Conclusion
C110 and T2 are equivalent high-purity electrolytic copper grades, while C122 and TP2 are equivalent phosphorus-deoxidized copper grades. Their identical compositions and properties ensure seamless use across international projects, with C110/T2 excelling in conductivity and C122/TP2 in welding and hydrogen embrittlement resistance. Understanding these equivalences simplifies material selection in global engineering applications.