1. High-Temperature Performance
INCOLOY retains mechanical strength (e.g., creep resistance) and corrosion resistance at temperatures up to 1000°C (1832°F) (depending on the grade). For example, INCOLOY 800HT is designed for long-term service at 800–950°C, making it ideal for furnace components or power plant superheaters.
Copper, by contrast, softens significantly above 200°C (392°F) and loses most structural integrity at ~500°C. Its melting point (1085°C) is high, but its poor high-temperature strength and oxidation resistance (it forms brittle oxide scales above 300°C) make it useless for high-temperature structural applications.
2. Corrosion Resistance
INCOLOY alloys (e.g., INCOLOY 825, 625) resist corrosion from oxidation, industrial atmospheres, high-temperature steam, and even mild acids (e.g., dilute sulfuric acid) due to their chromium and nickel content.
Copper is resistant to some mild conditions (e.g., non-oxidizing acids like dilute hydrochloric acid, or clean water), but it corrodes in:
High-temperature oxygen (forms CuO/Cu₂O scales).
Ammoniacal solutions (causes "ammonia corrosion").
Sulfur-containing environments (forms copper sulfide, leading to "sulfide stress cracking").
3. Mechanical Strength
Most INCOLOY grades (e.g., INCOLOY 909, a precipitation-hardened alloy) have a tensile strength of 1100–1250 MPa (160,000–181,000 psi) in their hardened state, with excellent creep resistance (resistance to permanent deformation under long-term stress).
Pure copper has a low tensile strength of only 200–300 MPa (29,000–43,500 psi) and no meaningful creep resistance at temperatures above 150°C. Even copper alloys (e.g., brass, bronze) rarely exceed 600 MPa tensile strength and still lack high-temperature durability.
4. Thermal & Electrical Conductivity
Copper has one of the highest thermal conductivities of any metal: ~401 W/(m·K) at 25°C, and high electrical conductivity (~58 MS/m). This makes it irreplaceable for applications like:
Electrical wiring/cables (transmits electricity with minimal loss).
Heat exchangers (e.g., HVAC coils, computer heat sinks) or heat pipes (transfers heat efficiently).
INCOLOY has very low thermal/electrical conductivity: ~15–25 W/(m·K) (thermal) and ~1–3 MS/m (electrical)-less than 10% of copper's conductivity. It is never used for heat/electricity transmission.
5. Cost & Weight
Copper is a common, widely produced metal with lower raw material costs than INCOLOY (which contains expensive nickel and chromium).
Copper has a lower density (~8.96 g/cm³) than most INCOLOY grades (~8.1–8.5 g/cm³ for INCOLOY 800/909)-a minor difference, but relevant for weight-sensitive designs where conductivity is critical.
Conclusion: When to Choose Which?
Choose INCOLOY if: The application requires high-temperature strength (above 300°C), corrosion resistance in aggressive environments (e.g., industrial chemicals, high-temperature steam), or structural durability under long-term stress (e.g., power plant components, furnace parts, chemical reactors).
Choose Copper if: The application prioritizes thermal/electrical conductivity (e.g., wiring, heat sinks), operates at low temperatures (<200°C), and only requires resistance to mild corrosion (e.g., domestic plumbing, low-voltage electronics).
