UNS R05255 Tantalum-Tungsten Alloy
R05255 alloy is a tantalum alloy. Cited properties are appropriate for the annealed condition. It has a fairly high density among alloys in the same category. In addition, it has a fairly low heat capacity and a moderately high tensile strength.
The graph bars on the material properties cards below compare R05255 alloy to: tantalum 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
190 GPa 27 x 106 psi
Elongation at Break
20 %
Poisson's Ratio
0.34
Shear Modulus
70 GPa 10 x 106 psi
Tensile Strength: Ultimate (UTS)
540 MPa 79 x 103 psi
Tensile Strength: Yield (Proof)
450 MPa 65 x 103 psi
Thermal Properties
Latent Heat of Fusion
140 J/g
Specific Heat Capacity
140 J/kg-K 0.034 BTU/lb-°F
Thermal Conductivity
59 W/m-K 34 BTU/h-ft-°F
Thermal Expansion
6.6 µm/m-K
Otherwise Unclassified Properties
Density
17 g/cm3 1040 lb/ft3
Embodied Water
630 L/kg 76 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
100 MJ/m3
Resilience: Unit (Modulus of Resilience)
530 kJ/m3
Stiffness to Weight: Axial
6.3 points
Stiffness to Weight: Bending
11 points
Strength to Weight: Axial
9.1 points
Strength to Weight: Bending
8.9 points
Thermal Diffusivity
25 mm2/s
Thermal Shock Resistance
31 points
Alloy Composition
| Ta | 95.9 to 98 | |
| W | 2.0 to 3.5 | |
| Nb | 0 to 0.5 | |
| Mo | 0 to 0.020 | |
| O | 0 to 0.015 | |
| C | 0 to 0.010 | |
| Ni | 0 to 0.010 | |
| Fe | 0 to 0.010 | |
| N | 0 to 0.010 | |
| Ti | 0 to 0.010 | |
| Si | 0 to 0.0050 | |
| H | 0 to 0.0015 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B365: Standard Specification for Tantalum and Tantalum Alloy Rod and Wire
ASTM B521: Standard Specification for Tantalum and Tantalum Alloy Seamless and Welded Tubes
ASTM B708: Standard Specification for Tantalum and Tantalum Alloy Plate, Sheet, and Strip
Tungsten: Properties, Chemistry, Technology of the Element, Alloys, and Chemical Compounds, Erik Lassner and Wolf-Dieter Schubert, 1999
Sintering of Advanced Materials: Fundamentals and Processes, Zhigang Zak Fang (editor), 2010