Cu-PHC Copper for Brazed Components: Why Low Phosphorus Content Matters

Cu-PHC Copper for Brazed Components: Material Selection & Processing

For brazed components, material selection involves more than purity and conductivity. Phosphorus content directly influences copper behavior during heating, forming, and joining. This is why Cu-PHC (EN CW020A / UNS C10300) is often specified for HVAC, refrigeration, heat exchangers, and fluid-handling systems.

The key question is whether phosphorus level, temper, and condition suit the intended brazing and forming process.

What Is Cu-PHC Copper?

Cu-PHC is a phosphorus-deoxidized copper grade (EN CW020A; UNS C10300). "PHC" stands for Phosphorus-deoxidized High-Conductivity copper. It is a deoxidized, essentially oxygen-free copper with very low oxygen (≤ 0.001% / ≤ 10 ppm) achieved by controlled phosphorus deoxidation.

Cu-PHC combines high conductivity (≥ 100% IACS, ~58 MS/m in annealed condition), good formability, and reliable thermal processing performance. Phosphorus is controlled—typically ≤ 0.006% (max. 60 ppm) for EN CW020A, commercial 20–50 ppm. UNS C10300 specifies 0.001%–0.005% (10–50 ppm); confirm applicable standard.

Unlike ETP copper (C11000) with 200–400 ppm oxygen, susceptible to hydrogen embrittlement during high-temperature joining, Cu-PHC is not susceptible. This distinction is critical for brazed components.

Cu-PHC is available in various forms and tempers: tube, strip, sheet, bar, rod, wire. Each form may require specific mechanical conditions for forming, bending, or assembly. Grade, temper, dimensions, and process must be specified together.

Why Low Phosphorus Matters in Copper?

Phosphorus deoxidizes copper but must be controlled. Insufficient P (<0.001%) may not deoxidize adequately; excessive P reduces conductivity and affects formability.

Balance deoxidation, conductivity, forming, and brazing. Cu-PHC maintains low P for high conductivity while ensuring reliable brazing/welding.

For brazed components (brazing at 600–800°C), controlled P is valuable. A properly specified P-deoxidized grade provides reliable heating behavior and high conductivity.

Buyers must consider standard, composition, temper, form, and joining method—not just copper purity.

Cu-PHC vs C12200: Composition & Processing

Both are P-deoxidized but differ in P content and conductivity. Not interchangeable. Equivalents depend on standard, form, and specification.

| Feature | Cu-PHC (CW020A / C10300) | C12200 (CW024A / Cu-DHP) |

| :--- | :--- | :--- |

| Copper base | High-purity | High-purity |

| Deoxidation | P (low) | P (higher) |

| Typical P content | ≤0.006% (max 60 ppm); commercial 20–50 ppm | 0.015–0.040% (150–400 ppm) |

| Conductivity | ≥100% IACS (~58 MS/m) | ~85–90% IACS |

| Oxygen | Very low, ≤10 ppm | Very low |

| Brazing | Excellent | Excellent |

| Formability | Good, temper-dependent | Good, temper-dependent |

| Applications | Brazed components, tubing, busbars, terminals | Tubes, heat exchangers, plumbing, fittings |

C12200 (Cu-DHP) is common for tubing and heat transfer. Its higher P lowers conductivity vs Cu-PHC. Verify applicable standards, not assume interchangeability.

Cu-PHC R240 for Brazed Components

"R240" indicates a mechanical temper affecting strength, hardness, ductility, and formability.

Per EN 13601 and industry data (Aurubis, Wieland), Cu-PHC R240 typically offers:

- Tensile strength: 240–300 MPa

- Yield strength (0.2%): ≥ 180 MPa

- Elongation (A50): ≥ 8%

- Hardness (HV): 65–95 HV

Select Cu-PHC R240 considering component geometry and fabrication. Brazed parts may require bending, drawing, expanding, or other forming before joining.

Proper temper balances forming needs with final mechanical performance. Also evaluate brazing procedure: heating temperature, joint design, filler metal, surface condition.

Industrial Applications of Cu-PHC

High conductivity, formability, and thermal joining suitability make Cu-PHC relevant for:

- HVAC and refrigeration tubing

- Heat exchangers and heat-transfer equipment

- Brazed fittings and assemblies

- Electrical busbars and terminals requiring high conductivity and brazed joints

- Plumbing components

- Fluid-transmission systems

These applications require efficient heat/fluid transfer and reliable brazed joints—why P-deoxidized grades, especially Cu-PHC, are specified.

Specifying Cu-PHC for Brazing

Provide sufficient information for supplier to identify correct material and condition. Confirm:

- Grade and standard: e.g., Cu-PHC EN CW020A / UNS C10300, governing standard (EN 13601, EN 1652, ASTM B152).

- Temper and dimensions: e.g., R240, thickness, diameter, width, etc.

- Product form and processing: tube, strip, sheet, bar, rod, or wire; brazing method and subsequent forming.

- Quality requirements: surface, testing, inspection, application-specific needs.

Reliable selection considers grade, temper, brazing process, and service conditions.

FAQ

What makes Cu-PHC different from ETP copper?

Cu-PHC is deoxidized, essentially oxygen-free (O ≤ 10 ppm); ETP (C11000) has 200–400 ppm O. In H₂-containing/reducing atmospheres at brazing temperatures, Cu-PHC is not susceptible to hydrogen embrittlement; ETP needs shielding or vacuum.

Is Cu-PHC suitable for refrigeration systems?

Yes. Used for tubing and components in refrigeration/HVAC where conductivity, forming, and brazing matter. Its resistance to hydrogen embrittlement enhances long-term joint reliability in sealed systems.

Can Cu-PHC be bent after annealing?

Yes. Proper temper/annealing provides ductility for bending. Limits depend on dimensions, geometry, and bend radius.

What does R240 mean?

R240 is a temper condition typically giving 240–300 MPa tensile, ≥180 MPa yield, ≥8% elongation, 65–95 HV. Confirm against applicable standard.

Is phosphorus beneficial during brazing?

Controlled P deoxidizes copper and prevents hydrogen embrittlement. But P must stay within specification to avoid excessive conductivity loss.

What to include in a Cu-PHC order?

Specify grade (Cu-PHC CW020A/C10300), standard (EN 13601, EN 1652, ASTM B152), temper (e.g., R240), form, dimensions, surface, brazing method, and testing/inspection requirements.

Standards referenced (for verification):

EN 13601: Copper and copper alloys – Copper rod, bar and wire for general electrical purposes

EN 1652: Copper and copper alloys – Plate, sheet, strip and circles

ASTM B152/B152M: Copper Sheet, Strip, Plate, and Rolled Bar

ASTM B280: Seamless Copper Tube for Air Conditioning and Refrigeration Field Service