ASTM B628 Silver-Copper Eutectic Electrical Contact Alloy
ASTM B628 Ag-Cu is a precious metal alloy formulated for use in electrical contacts. It has a moderately high electrical conductivity among the precious metal electrical contact alloys in the database.
The properties of ASTM B628 Ag-Cu include nine common variations. This page shows summary ranges across all of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare ASTM B628 Ag-Cu 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 to 17 %
Poisson's Ratio
0.36
Shear Modulus
31 GPa 4.4 x 106 psi
Shear Strength
210 to 430 MPa 31 to 63 x 103 psi
Tensile Strength: Ultimate (UTS)
350 to 760 MPa 50 to 110 x 103 psi
Thermal Properties
Latent Heat of Fusion
140 J/g
Melting Completion (Liquidus)
780 °C 1430 °F
Melting Onset (Solidus)
780 °C 1430 °F
Specific Heat Capacity
280 J/kg-K 0.066 BTU/lb-°F
Thermal Expansion
19 µm/m-K
Other Material Properties
Density
10 g/cm3 630 lb/ft3
Electrical Conductivity: Equal Volume
84 % IACS
Electrical Conductivity: Equal Weight (Specific)
75 % IACS
Common Calculations
Stiffness to Weight: Axial
4.6 points
Stiffness to Weight: Bending
14 points
Strength to Weight: Axial
9.5 to 21 points
Strength to Weight: Bending
11 to 18 points
Thermal Shock Resistance
16 to 34 points
Alloy Composition
| Ag | 71 to 73 | |
| Cu | 26.6 to 29 | |
| Zn | 0 to 0.060 | |
| Fe | 0 to 0.050 | |
| Cd | 0 to 0.050 | |
| P | 0 to 0.030 | |
| Pb | 0 to 0.030 | |
| Ni | 0 to 0.010 | |
| Al | 0 to 0.0050 | |
| res. | 0 to 0.21 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B628: Standard Specification for Silver-Copper Eutectic Electrical Contact Alloy
CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015