Quarter-Hard ASTM B780 Silver-Copper-Nickel Alloy
Quarter-hard ASTM B780 alloy is ASTM B780 alloy in the quarter-hard temper. The graph bars on the material properties cards below compare quarter-hard 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
4.6 %
Poisson's Ratio
0.36
Shear Modulus
30 GPa 4.4 x 106 psi
Shear Strength
230 MPa 34 x 103 psi
Tensile Strength: Ultimate (UTS)
410 MPa 59 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
74 % IACS
Electrical Conductivity: Equal Weight (Specific)
66 % IACS
Common Calculations
Stiffness to Weight: Axial
4.5 points
Stiffness to Weight: Bending
14 points
Strength to Weight: Axial
11 points
Strength to Weight: Bending
12 points
Thermal Shock Resistance
20 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