Spring-Tempered ASTM B780 Silver-Copper-Nickel Alloy
Spring-tempered ASTM B780 alloy is ASTM B780 alloy in the spring temper. It has the highest strength and lowest ductility compared to the other variants of ASTM B780 alloy.
The graph bars on the material properties cards below compare spring-tempered ASTM B780 alloy to: precious metal electrical contact alloys (top), all alloys in the same category (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
Elastic (Young's, Tensile) Modulus
83 GPa 12 x 106 psi
Elongation at Break
1.1 %
Fatigue Strength
280 MPa 41 x 103 psi
Poisson's Ratio
0.36
Shear Modulus
30 GPa 4.4 x 106 psi
Shear Strength
340 MPa 49 x 103 psi
Tensile Strength: Ultimate (UTS)
590 MPa 86 x 103 psi
Tensile Strength: Yield (Proof)
460 MPa 66 x 103 psi
Thermal Properties
Latent Heat of Fusion
140 J/g
Melting Completion (Liquidus)
860 °C 1580 °F
Specific Heat Capacity
270 J/kg-K 0.065 BTU/lb-°F
Thermal Expansion
18 µm/m-K
Other Material Properties
Density
10 g/cm3 630 lb/ft3
Electrical Conductivity: Equal Volume
70 % IACS
Electrical Conductivity: Equal Weight (Specific)
62 % IACS
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
6.2 MJ/m3
Resilience: Unit (Modulus of Resilience)
1250 kJ/m3
Stiffness to Weight: Axial
4.5 points
Stiffness to Weight: Bending
14 points
Strength to Weight: Axial
16 points
Strength to Weight: Bending
15 points
Thermal Shock Resistance
29 points
Alloy Composition
| Ag | 74 to 76 | |
| Cu | 23.5 to 25.7 | |
| Ni | 0.35 to 0.65 | |
| Zn | 0 to 0.060 | |
| Fe | 0 to 0.050 | |
| Cd | 0 to 0.050 | |
| Pb | 0 to 0.030 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Further Reading
ASTM B780: Standard Specification for 75% Silver, 24.5% Copper, 0.5% Nickel Electrical Contact Alloy