inconel 718 for aerospace applications

Inconel 718 is widely used in aerospace for its unique strength, corrosion resistance, and high-temperature performance. This article will explore the top 5 properties that make this nickel alloy advantageous for aircraft engines and structural components.

High Strength

Inconel 718 is prized in aerospace applications for its exceptional strength. This nickel-chromium alloy maintains high tensile, yield, and shear strengths even when exposed to elevated temperatures and stress loads.

For example, Inconel 718 exhibits a tensile strength of over 1,000 MPa and 0.2% yield strength of over 900 MPa even after prolonged exposure to 700°C. Such strength allows the use of thinner sections in engine components, resulting in significant weight savings.

Inconel 718’s strength comes from solid solution strengthening by molybdenum and niobium, as well as precipitation hardening from gamma prime and gamma double prime phases.

With capabilities like these, it’s no wonder Inconel 718 is the go-to solution for high-performance aerospace structures and components. When sourcing Inconel 718 for your aerospace application, be sure to check out this page on Inconel 718’s material properties to ensure you get an alloy that meets your exacting needs.

Outstanding Fatigue Resistance

Inconel 718 demonstrates exceptional fatigue strength and the ability to withstand cyclic stress loads without failure. This is critical for aerospace applications where components experience repetitive stress cycles over long service lives.

Specifically, Inconel 718 alloys retain impressive fatigue strength even after prolonged exposures to high temperatures. For example, at 650°C Inconel 718 provides a fatigue strength of nearly 300 MPa for 107 cycles. The fatigue life remains high at elevated temperatures up to 700°C.

Such outstanding fatigue resistance allows engineers to design lighter aerospace components with confidence they will perform reliably over thousands of flight cycles without cracking or failure. This ensures greater aircraft safety and longevity.

With its balance of strength, corrosion resistance, and remarkably high fatigue properties, Inconel 718 continues to be the go-to solution for critical rotating parts like discs and cases subject to high stresses in turbine engines.

Excellent Corrosion Resistance

Inconel 718 demonstrates excellent resistance to various forms of corrosion that can degrade engine components exposed to hot gases.

For instance, this alloy exhibits outstanding resistance to hot corrosion caused by salts and sulfur compounds that are ingested or formed within gas turbine engines. Even after prolonged exposures to aggressive environments with temperatures exceeding 700°C, Inconel 718 resists corrosion through the formation of protective chromium oxide scales.

Inconel 718 also provides impressive corrosion resistance in the marine atmospheres common for navy and offshore applications. The alloy exhibits corrosion rates less than 25 μm per year in highly saline environments.

Such corrosion capabilities allow Inconel 718 to protect critical components like disks, cases, fasteners, and actuators in hot sections of turbine engines across aviation, marine and industrial applications.

When you need an advanced alloy that combines high strength with corrosion resistance for your harshest environments, Inconel 718 is an excellent candidate as reinforced by its material properties.

Good Oxidation Resistance

In addition to corrosion resistance, this nickel alloy demonstrates good oxidation resistance in high temperature environments. This allows the metal to withstand degradation from prolonged exposures to oxygen and other oxidizing species.

For instance, the alloy exhibits oxidation rates less than 2 mg/cm2 after thousands of hours of testing in air atmospheres at temperatures approaching 1000°C. This oxidation resistance results from the formation of tightly adherent chromium oxide scales that protect the underlying material.

Even after extensive hot temperature exposure, the alloy retains most of its mechanical properties including strength, ductility and fatigue resistance. This allows components to remain in service despite ongoing oxidation.

The balanced composition provides remarkable capabilities to resist oxidation damage. This is a key enabler for hot section aerospace components and ensures engines can operate reliably after years of service.

Review the high temperature oxidation data for yourself on the alloy’s properties page to see why it outperforms other alloys.

Great Weldability

A key advantage of this nickel alloy is its excellent weldability using conventional fusion welding methods. This makes the alloy well suited for fabricating complex aerospace components.

The metal can be readily welded with matching filler metals. Using optimized procedures, welds can retain over 90% of the base metal strength with proper heat treatment after welding.

The weldability allows engineers to design integrated structures joined together through welding rather than mechanical fasteners. This improves overall manufacturing efficiency.

The combination of weldability, strength and corrosion resistance make the alloy an ideal choice for fabricating critical hot section components like frames, cases and liners from sheet and plate stock.

When specifying alloy needs, be sure to check out the recommended welding guidelines to achieve optimal joint properties. The versatility helps make it a staple alloy for aerospace applications.

With its exceptional strength, fatigue resistance, corrosion resistance, and oxidation resistance, Inconel 718 is the top choice for performance-critical aerospace applications. This nickel-based alloy enables lighter, more efficient components that continue performing safely after years of harsh operating environments.

As researchers develop even higher-strength alloys, Inconel 718 provides aerospace manufacturers with a proven balance of properties they can rely on. When you need confidence your next aerospace component will survive the long haul, be sure to utilize this alloy’s versatile mechanical properties. With proper processing and heat treatment, Inconel 718 can provide reliable solutions for the toughest applications.

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