Infiltrated ASTM B631 Class B Silver-Tungsten Alloy
Infiltrated ASTM B631 class B is a type of ASTM B631 class B. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. The graph bars on the material properties cards below compare infiltrated ASTM B631 class B 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
210 GPa 30 x 106 psi
Flexural Strength
790 MPa 110 x 103 psi
Poisson's Ratio
0.31
Rockwell B Hardness
80
Shear Modulus
78 GPa 11 x 106 psi
Tensile Strength: Ultimate (UTS)
380 MPa 55 x 103 psi
Thermal Properties
Latent Heat of Fusion
150 J/g
Specific Heat Capacity
170 J/kg-K 0.040 BTU/lb-°F
Thermal Conductivity
450 W/m-K 260 BTU/h-ft-°F
Thermal Expansion
12 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
53 % IACS
Electrical Conductivity: Equal Weight (Specific)
34 % IACS
Otherwise Unclassified Properties
Density
14 g/cm3 880 lb/ft3
Embodied Carbon
49 kg CO2/kg material
Embodied Energy
760 MJ/kg 330 x 103 BTU/lb
Common Calculations
Stiffness to Weight: Axial
8.1 points
Stiffness to Weight: Bending
14 points
Strength to Weight: Axial
7.5 points
Strength to Weight: Bending
8.3 points
Thermal Diffusivity
190 mm2/s
Thermal Shock Resistance
11 points
Alloy Composition
| W | 60.6 to 67 | |
| Ag | 33 to 37 | |
| Co | 0 to 1.0 | |
| C | 0 to 0.2 | |
| Cu | 0 to 0.2 | |
| res. | 0 to 1.0 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B631: Standard Specification for Silver-Tungsten Electrical Contact Materials
Tungsten: Properties, Chemistry, Technology of the Element, Alloys, and Chemical Compounds, Erik Lassner and Wolf-Dieter Schubert, 1999