UNS C91000 Tin Bronze
C91000 bronze is a bronze formulated for casting. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. C91000 is the UNS number for this material. Additionally, the common industry name is 85-15 Tin Bronze.
It has a very high embodied energy among cast bronzes. In addition, it has a very high base cost and a fairly low melting temperature.
The graph bars on the material properties cards below compare C91000 bronze to: cast bronzes (top), all copper alloys (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Brinell Hardness
180
Elastic (Young's, Tensile) Modulus
110 GPa 15 x 106 psi
Elongation at Break
7.0 %
Poisson's Ratio
0.34
Shear Modulus
39 GPa 5.7 x 106 psi
Tensile Strength: Ultimate (UTS)
230 MPa 34 x 103 psi
Tensile Strength: Yield (Proof)
150 MPa 21 x 103 psi
Thermal Properties
Latent Heat of Fusion
180 J/g
Maximum Temperature: Mechanical
160 °C 310 °F
Melting Completion (Liquidus)
960 °C 1760 °F
Melting Onset (Solidus)
820 °C 1500 °F
Specific Heat Capacity
360 J/kg-K 0.087 BTU/lb-°F
Thermal Conductivity
64 W/m-K 37 BTU/h-ft-°F
Thermal Expansion
18 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
9.0 % IACS
Electrical Conductivity: Equal Weight (Specific)
9.4 % IACS
Otherwise Unclassified Properties
Base Metal Price
37 % relative
Density
8.6 g/cm3 540 lb/ft3
Embodied Carbon
4.1 kg CO2/kg material
Embodied Energy
67 MJ/kg 29 x 103 BTU/lb
Embodied Water
420 L/kg 51 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
14 MJ/m3
Resilience: Unit (Modulus of Resilience)
100 kJ/m3
Stiffness to Weight: Axial
6.8 points
Stiffness to Weight: Bending
18 points
Strength to Weight: Axial
7.5 points
Strength to Weight: Bending
9.7 points
Thermal Diffusivity
20 mm2/s
Thermal Shock Resistance
8.8 points
Alloy Composition
Among cast copper alloys, the composition of C91000 bronze is notable for containing a comparatively high amount of tin (Sn) and including sulfur (S). Tin is used to improve strength, bearing properties, and corrosion resistance against certain types of media. It also places certain constraints on cast part design, so as to avoid porosity problems. Sulfur is used to improve machinability at the cost of a decrease in electrical conductivity.
| Cu | 84 to 86 | |
| Sn | 14 to 16 | |
| P | 0 to 1.5 | |
| Zn | 0 to 1.5 | |
| Ni | 0 to 0.8 | |
| Pb | 0 to 0.2 | |
| Sb | 0 to 0.2 | |
| Fe | 0 to 0.1 | |
| S | 0 to 0.050 | |
| Si | 0 to 0.0050 | |
| Al | 0 to 0.0050 | |
| res. | 0 to 0.6 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B505: Standard Specification for Copper Alloy Continuous Castings
ASM Specialty Handbook: Copper and Copper Alloys, J. R. Davis (editor), 2001