Hardened Copper Alloy with High Hardness and Thermal Stability
Copper-beryllium alloys containing cobalt or a combination of nickel and cobalt remain mechanically stable up to 550 °C. This makes them suitable for conductive components exposed to thermal and mechanical loads.
CuCo₂Be contains approximately 2.0% cobalt. In CuCo₁Ni₁Be, the cobalt content is reduced to 1.0% and replaced by 1.0% nickel. Both alloys show similar mechanical properties. CuCo₁Ni₁Be has a slight advantage in terms of conductivity.
Compared to standard CuBe alloys, CuCo₂Be achieves higher electrical and thermal conductivity. Mechanical properties can be adjusted by cold forming and subsequent precipitation hardening.
Composition of Copper-Cobalt-Beryllium
- 29
Copper
Cu
97.2 – 97.6%
- 27
Cobalt
Co
2.0%
- 4
Beryllium
Be
0.4 – 0.8%
Composition of Copper-Cobalt-Nickel-Beryllium
- 29
Copper
Cu
97.2 – 97.6%
- 27
Cobalt
Co
1.0%
- 28
Nickel
Ni
1.0%
- 4
Beryllium
Be
0.4 – 0.8%
Key Properties
Mechanical Strength
CuCoBe develops high strength after precipitation hardening without compromising conductivity. This is due to nanoscale Be-Co precipitates that effectively block dislocation motion. CuCoNiBe reaches a similar strength level but shows slightly lower hardness and conductivity. Both alloys offer a unique combination of properties among copper-based materials.
Thermal Stability
CuCoBe remains stable up to approximately 500 °C. The addition of nickel gives CuCoNiBe an even higher softening temperature, exceeding 520 °C. Both are suitable for thermally demanding applications. In die-casting tools, they allow for a high number of cycles at elevated temperatures without losing strength.
Stress Corrosion Resistance
Unlike many high-strength copper alloys, both CuCoBe and CuCoNiBe show strong resistance to stress corrosion, even under tensile load in aggressive environments. Unlike many high-strength copper alloys, they do not tend to form microcracks under combined mechanical and chemical stress.
Physical and Mechanical Properties
Property Name | Unit | CuCoBe | CuCoNiBe |
|---|---|---|---|
Tensile strength (Rm) | MPa | 900–1200 | 900–1100 |
Yield strength (Rp0.2) | MPa | 600–900 | 600–900 |
Elongation at break (A) | % | 12–15 | 5–15 |
Hardness (Brinell) | HBW 2.5/62.5 | 220–280 | 160–190 |
Hardness (Vickers) | HV | > 230 | 170–210 |
Electrical conductivity | MS/m | 18–30 | 14.5–18.5 |
Electrical conductivity | % IACS | ≥ 42 | 25–32 |
Density at 20 °C | g/cm³ | ≥ 8.3 | 8.5–8.7 |
Melting temperature (liquidus) | °C | 1060–1080 | 1020–1060 |
Linear expansion coefficient (20 °C–300 °C) | x 10⁻⁶/K⁻¹ | 16–17 | 16–17 |
Modulus of elasticity | kN/mm² | 125–135 | 125–135 |
Thermal conductivity at 20 °C | W/(m·K) | ≥ 200 | 190–230 |
Softening temperature | °C | 500 | ≥ 520 |
These figures represent minimum values, typical averages or defined tolerance ranges. If your application requires specific material characteristics such as a defined hardness or higher flexibility, we will develop a suitable variant in close cooperation with you. Get in touch to discuss your specifications.
Industrial Applications
Typical use cases for CuCo(Ni)Be in industrial environments
Welding Technology
High temperature stability, dimensional consistency and wear resistance ensure reliable performance in resistance welding processes such as spot, seam, projection and butt welding. They are commonly used for electrodes, holders and electrode arms.
Electrical Engineering
A combination of high conductivity, thermal stability and mechanical strength makes them suitable for components exposed to high current loads such as contacts, busbars and terminals in switchgear and control devices.
Die Casting
Their thermal conductivity and stability under high temperatures reduce heat accumulation and tool wear. They are used in inserts, cores and slides in die casting tools with short cycle times.
Tool Making
These alloys maintain tight dimensional tolerances even under combined mechanical and thermal stress. This makes them a suitable choice for EDM electrodes, especially in demanding applications with tight tolerances or complex geometries.
CuCo(Ni)Be Welding Parts
Manufacturing Process
The production of a CuCoBe rod involves multiple steps to achieve the desired material properties.
- 1Step 1
Alloy preparation
Pure copper, cobalt and beryllium are weighed according to a defined recipe and melted in a high-temperature furnace. The temperature is continuously monitored. At the same time, the alloy composition is regularly checked to ensure a homogeneous melt. This precise control is critical for the final material properties.
- 2Step 2
Casting and homogenisation
The molten alloy is cast into moulds and allowed to solidify into billets. These semi-finished products are then homogenised for several hours at high temperatures. This equalises the microstructure, removes chemical segregation from casting and prepares the material for forming.
- 3Step 3
Hot rolling
The billets are reheated and rolled to the required size. Hot rolling increases density, reduces casting defects and promotes a uniform grain structure. Precisely controlled rolling parameters ensure dimensional accuracy over the full length.
- 4Step 4
Cold working
The hot-rolled rods are drawn through dies to achieve the final dimensions and surface finish. Cold deformation also increases strength.
- 5Step 5
Heat treatment
To improve mechanical properties, CuCoBe rods are heat treated. Controlled heating at defined temperatures creates a fine precipitation structure within the matrix. This precipitation hardening significantly increases strength.
- 6Step 6
Surface treatment
Surface treatments are used to remove contaminants and selectively increase corrosion resistance. Depending on the requirements, mechanical methods such as grinding or polishing are used, as well as chemical treatments. A flawless surface is essential, especially for applications in corrosive environments.
- 7Step 7
Quality control
CuCoBe rods undergo stringent quality checks throughout the entire manufacturing process. This includes testing for chemical composition, mechanical properties, dimensional accuracy and surface condition. Analytical methods include X-ray fluorescence (XRF) and image-based measurement systems to ensure full compliance with specifications.
- 8Step 8
Packaging and shipping
The finished rods are packaged and prepared for shipment. Special packaging materials are used to protect the rods from damage during transport.
This process ensures that CuCoBe rods develop the material characteristics required for industrial use. These include high strength, electrical and thermal conductivity, and wear resistance.
Talk to Our Material Specialists
In close cooperation with you, we analyse your requirements, provide comprehensive guidance and find the solution that fits your process best.
