Inconel 718
A precipitation-hardened nickel-chromium superalloy engineered for extreme environments. Inconel 718 maintains mechanical properties at temperatures up to 700 °C, making it essential for turbine components, rocket engines, and nuclear applications.
About Inconel 718
Inconel 718 is the most widely used nickel superalloy in additive manufacturing. Its combination of high tensile strength (up to 1,400 MPa after aging), creep resistance, and oxidation stability at elevated temperatures makes it irreplaceable in aerospace propulsion, power generation, and oil & gas applications.
The alloy is strengthened by gamma-prime (γ') and gamma-double-prime (γ'') precipitates formed during a multi-step heat treatment: solution annealing at ~980 °C followed by double aging at 720 °C and 620 °C. This aging process is critical — as-built properties differ significantly from heat-treated properties.
AM-produced IN718 typically achieves >99.5% relative density via LPBF. The material welds well (unlike some nickel superalloys), which aids repair and hybrid manufacturing workflows.
Key challenges include residual stress management during builds, mandatory HIP + heat treatment for critical applications, and relatively slow build rates due to high energy input requirements.
Typical Applications
- Gas turbine blades, vanes, and combustion chambers
- Rocket engine nozzles and injectors
- Nuclear reactor components
- Oil & gas downhole tooling
- High-temperature fasteners and springs
Engineering Considerations
- Multi-step heat treatment (solution + double age) is mandatory for target properties
- High residual stress — careful build orientation and support strategy required
- HIP recommended for fatigue-critical aerospace and nuclear parts
- Material cost is 3–5× stainless steel — budget accordingly
- Post-machining is difficult due to work hardening (requires rigid setups and sharp tooling)