UNS R05240 Tantalum-Niobium Alloy
R05240 alloy is a tantalum alloy. Cited properties are appropriate for the annealed condition. It has a moderately high density among the alloys in the same category in the database. The graph bars on the material properties cards below compare R05240 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
150 GPa 22 x 106 psi
Elongation at Break
25 %
Poisson's Ratio
0.36
Shear Modulus
57 GPa 8.2 x 106 psi
Tensile Strength: Ultimate (UTS)
270 MPa 39 x 103 psi
Tensile Strength: Yield (Proof)
170 MPa 24 x 103 psi
Thermal Properties
Latent Heat of Fusion
210 J/g
Specific Heat Capacity
190 J/kg-K 0.045 BTU/lb-°F
Thermal Expansion
6.8 µm/m-K
Otherwise Unclassified Properties
Density
14 g/cm3 850 lb/ft3
Embodied Water
460 L/kg 55 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
59 MJ/m3
Resilience: Unit (Modulus of Resilience)
90 kJ/m3
Stiffness to Weight: Axial
6.3 points
Stiffness to Weight: Bending
13 points
Strength to Weight: Axial
5.4 points
Strength to Weight: Bending
6.8 points
Thermal Shock Resistance
18 points
Alloy Composition
| Ta | 57.9 to 65 | |
| Nb | 35 to 42 | |
| W | 0 to 0.050 | |
| Mo | 0 to 0.020 | |
| O | 0 to 0.020 | |
| 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
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
Extractive Metallurgy of Niobium, C. K. Gupta and A. K. Suri, 1993
Sintering of Advanced Materials: Fundamentals and Processes, Zhigang Zak Fang (editor), 2010