UNS C87200 Silicon Bronze
C87200 bronze is a bronze formulated for casting. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. It has a fairly low thermal conductivity among cast bronzes. In addition, it has a very low electrical conductivity and a very high ductility.
The graph bars on the material properties cards below compare C87200 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
85
Elastic (Young's, Tensile) Modulus
110 GPa 17 x 106 psi
Elongation at Break
30 %
Poisson's Ratio
0.34
Shear Modulus
43 GPa 6.2 x 106 psi
Tensile Strength: Ultimate (UTS)
380 MPa 55 x 103 psi
Tensile Strength: Yield (Proof)
170 MPa 25 x 103 psi
Thermal Properties
Latent Heat of Fusion
260 J/g
Maximum Temperature: Mechanical
200 °C 380 °F
Melting Completion (Liquidus)
970 °C 1780 °F
Melting Onset (Solidus)
860 °C 1580 °F
Specific Heat Capacity
410 J/kg-K 0.1 BTU/lb-°F
Thermal Conductivity
28 W/m-K 16 BTU/h-ft-°F
Thermal Expansion
17 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
6.0 % IACS
Electrical Conductivity: Equal Weight (Specific)
6.3 % IACS
Otherwise Unclassified Properties
Base Metal Price
29 % relative
Density
8.6 g/cm3 540 lb/ft3
Embodied Carbon
2.7 kg CO2/kg material
Embodied Energy
44 MJ/kg 19 x 103 BTU/lb
Embodied Water
310 L/kg 37 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
93 MJ/m3
Resilience: Unit (Modulus of Resilience)
130 kJ/m3
Stiffness to Weight: Axial
7.4 points
Stiffness to Weight: Bending
19 points
Strength to Weight: Axial
12 points
Strength to Weight: Bending
14 points
Thermal Diffusivity
8.0 mm2/s
Thermal Shock Resistance
14 points
Alloy Composition
Among cast copper alloys, the composition of C87200 bronze is notable for containing comparatively high amounts of silicon (Si) and iron (Fe). Silicon is used to improve casting fluidity and lower melting temperature. It also raises strength at the expense of ductility. Iron is used to increase strength inexpensively.
| Cu | 89 to 99 | |
| Si | 1.0 to 5.0 | |
| Zn | 0 to 5.0 | |
| Fe | 0 to 2.5 | |
| Mn | 0 to 1.5 | |
| Al | 0 to 1.5 | |
| Sn | 0 to 1.0 | |
| P | 0 to 0.5 | |
| Pb | 0 to 0.5 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASM Specialty Handbook: Copper and Copper Alloys, J. R. Davis (editor), 2001