Bronze C630 properties
Chemical composition
Section titled “Chemical composition”Alloy C630 nominally contains 82% copper and is characterized by the addition of aluminum, nickel, and iron. The table below shows the typical chemical composition according to UNS C63000 designation.
| Element | Content (%) |
|---|---|
| Copper, Cu | 82.0 |
| Aluminum, Al | 10.0 |
| Nickel, Ni | 5.0 |
| Iron, Fe | 3.0 |
Mechanical properties
Section titled “Mechanical properties”Bronze C630 achieves a tensile strength of 760 MPa in the forged and heat-treated condition. The representative mechanical properties are summarized below.
| Property | Condition | Metric | Imperial |
|---|---|---|---|
| Tensile strength | Forged | 760 MPa | 110 000 psi |
| Yield strength (0.2 %) | Forged | 470 MPa | 68 200 psi |
| Elongation at break (in 50 mm) | Forged | 10 % | 10 % |
| Reduction of area (at 316 °C, cold finished) | – | 9 % | 9 % |
| Elastic modulus | – | 117 GPa | 17 000 ksi |
| Shear modulus | – | 44.0 GPa | 6380 ksi |
| Fatigue strength (1.0×10⁸ cycles, alternating bending) | – | 255 MPa | 37 000 psi |
| Rockwell B hardness | – | 94 | 94 |
| Poisson’s ratio | – | 0.34 | 0.34 |
Physical properties
Section titled “Physical properties”The density of bronze C630 is 7.58 g/cm³ and its melting point is 1035 °C. The main values are given in the following table.
| Property | Metric | Imperial |
|---|---|---|
| Density | 7.58 g/cm³ | 0.274 lb/in³ |
| Melting point | 1035 °C | 1895 °F |
Thermal properties
Section titled “Thermal properties”The thermal conductivity of alloy C630 is 37.7 W/m·K at 20 °C. The table below shows the available thermal data.
| Property | Conditions | Metric | Imperial |
|---|---|---|---|
| Coefficient of thermal expansion | 20 – 300 °C | 16.2 µm/m·°C | 9.0 µin/in·°F |
| Thermal conductivity | at 20 °C | 37.7 W/m·K | 262 BTU·in/hr·ft²·°F |
Machinability
Section titled “Machinability”The machinability of bronze C630 is rated at 30, taking 100 as the reference for free-cutting brass C36000. The use of carbide or high-speed steel tools with moderate cutting speeds and abundant coolant is recommended to evacuate the long, abrasive chips generated by the alloy.
Welding
Section titled “Welding”Brazing, gas shielded arc welding (TIG/MIG), shielded metal arc welding, resistance welding (spot, seam, and butt) are suitable for bronze C630. In contrast, soft soldering and oxyacetylene welding are not recommended for this alloy due to the risk of cracking and embrittlement.
Forming
Section titled “Forming”Bronze C630 exhibits good hot forgeability, with a hot forgeability rating of 75. The recommended temperature range for hot working extends from 788 °C to 927 °C. Cold forming is limited, although it can be performed with intermediate anneals; cold finishing is used to achieve the reduction of area recorded in the mechanical properties.
Heat treatments
Section titled “Heat treatments”Annealing of bronze C630 is carried out by heating to temperatures between 704 °C and 788 °C, followed by controlled cooling. This treatment relieves internal stresses and homogenizes the microstructure. Hardening of the alloy is achieved mainly by hot working and cooling, not by precipitation.
Applications by industry
Section titled “Applications by industry”The corrosion resistance and high mechanical properties of bronze C630 make it suitable for multiple sectors. It is used in:
| Industry | Representative applications |
|---|---|
| Naval and marine | Propellers, shafts, pumps, valves, sonar housings, hull fittings |
| Oil and petrochemical | Spark-proof tools, valve bodies, offshore platform components |
| Aerospace | Friction bearings, landing gear components |
| Power generation | Valve seats and discs in turbines, corrosion-resistant parts for marine environments |
Comparison with similar materials
Section titled “Comparison with similar materials”Compared to nickel-free aluminum bronzes (for example, CuAl10Fe3), C630 offers higher marine corrosion resistance and retention of mechanical properties at elevated temperatures due to its nickel content. Compared to austenitic stainless steels, it has 5‑10% lower density, four times higher thermal conductivity, and is non-magnetic, making it ideal for sonar enclosures and equipment sensitive to magnetic fields. Compared to other bronzes of the C632 series (CuAl9Ni4Fe4), C630 is distinguished by a slightly richer aluminum composition and lower iron content, which gives it higher tensile strength but more limited weldability.
Frequently Asked Questions (FAQ)
Section titled “Frequently Asked Questions (FAQ)”What is the tensile strength of bronze C630?
Section titled “What is the tensile strength of bronze C630?”The tensile strength of bronze C630 is 760 MPa in the forged condition.
What is the Rockwell B hardness of bronze C630?
Section titled “What is the Rockwell B hardness of bronze C630?”The Rockwell B hardness of bronze C630 is 94.
At what temperature does bronze C630 melt?
Section titled “At what temperature does bronze C630 melt?”Bronze C630 melts at 1035 °C.
What is the machinability rating of bronze C630?
Section titled “What is the machinability rating of bronze C630?”The machinability rating of bronze C630 is 30, referenced to a scale where brass C36000 equals 100.
What is the thermal conductivity of bronze C630 at 20 °C?
Section titled “What is the thermal conductivity of bronze C630 at 20 °C?”The thermal conductivity of bronze C630 at 20 °C is 37.7 W/m·K.
What is the coefficient of thermal expansion of bronze C630 between 20 °C and 300 °C?
Section titled “What is the coefficient of thermal expansion of bronze C630 between 20 °C and 300 °C?”The coefficient of thermal expansion of bronze C630 between 20 °C and 300 °C is 16.2 µm/m·°C.
References
Section titled “References”- azom.com: https://www.azom.com/article.aspx?ArticleID=8922
- engineeringtoolbox.com: https://www.engineeringtoolbox.com/properties-aluminum-pipe-d_1340.html
- steelnumber.com: https://www.steelnumber.com/en/steel_alloy_composition_eu.php?name_id=2172