Direct Aged N07718 Nickel Alloy
Direct aged nickel 718 is nickel 718 in the aged (precipitation hardened) condition. It has the highest strength and second lowest ductility compared to the other variants of nickel 718. The graph bars on the material properties cards below compare direct aged nickel 718 to: wrought nickels (top), all nickel alloys (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 28 x 106 psi
Elongation at Break
19 %
Fatigue Strength
760 MPa 110 x 103 psi
Fracture Toughness
220 MPa-m1/2 200 x 103 psi-in1/2
Poisson's Ratio
0.29
Reduction in Area
34 %
Rockwell C Hardness
40
Shear Modulus
75 GPa 11 x 106 psi
Shear Strength
950 MPa 140 x 103 psi
Tensile Strength: Ultimate (UTS)
1530 MPa 220 x 103 psi
Tensile Strength: Yield (Proof)
1330 MPa 190 x 103 psi
Thermal Properties
Curie Temperature
-110 °C -170 °F
Latent Heat of Fusion
310 J/g
Maximum Temperature: Mechanical
980 °C 1790 °F
Melting Completion (Liquidus)
1340 °C 2440 °F
Melting Onset (Solidus)
1260 °C 2300 °F
Specific Heat Capacity
450 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
11 W/m-K 6.5 BTU/h-ft-°F
Thermal Expansion
13 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
1.4 % IACS
Electrical Conductivity: Equal Weight (Specific)
1.5 % IACS
Otherwise Unclassified Properties
Base Metal Price
75 % relative
Density
8.3 g/cm3 520 lb/ft3
Embodied Carbon
13 kg CO2/kg material
Embodied Energy
190 MJ/kg 80 x 103 BTU/lb
Embodied Water
250 L/kg 30 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
280 MJ/m3
Resilience: Unit (Modulus of Resilience)
4560 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
23 points
Strength to Weight: Axial
51 points
Strength to Weight: Bending
35 points
Thermal Diffusivity
3.0 mm2/s
Thermal Shock Resistance
44 points
Alloy Composition
| Ni | 50 to 55 | |
| Cr | 17 to 21 | |
| Fe | 11.1 to 24.6 | |
| Nb | 4.8 to 5.5 | |
| Mo | 2.8 to 3.3 | |
| Ti | 0.65 to 1.2 | |
| Co | 0 to 1.0 | |
| Al | 0.2 to 0.8 | |
| Mn | 0 to 0.35 | |
| Si | 0 to 0.35 | |
| Cu | 0 to 0.3 | |
| C | 0 to 0.080 | |
| P | 0 to 0.015 | |
| S | 0 to 0.015 | |
| B | 0 to 0.0060 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Further Reading
Welding Metallurgy and Weldability of Nickel-Base Alloys, John C. Lippold et al., 2009
ASM Specialty Handbook: Nickel, Cobalt, and Their Alloys, Joseph R. Davis (editor), 2000
Aerospace Materials, Brian Cantor et al. (editors), 2001
Engineering Properties of Nickel and Nickel Alloys, John L. Everhart, 1971
Nickel Alloys, Ulrich Heubner (editor), 1998