Inconel 718 is a nickel-chromium-molybdenum alloy that has made a significant impact in a variety of industries, thanks to its exceptional mechanical properties, corrosion resistance, and high-temperature stability. Investment casting is one of the most popular ways to manufacture intricate parts from this alloy.
Inconel 718 Chemical Compositions
| Element | Percentage (%) |
|---|---|
| Nickel (Ni) | 50-55 |
| Chromium (Cr) | 17-21 |
| Molybdenum (Mo) | 2.8-3.3 |
| Niobium (Nb) | 4.75-5.5 |
| Titanium (Ti) | 0.65-1.15 |
| Aluminum (Al) | 0.2-0.8 |
| Iron (Fe) | Balance |
| Cobalt (Co) | ≤ 1 |
| Manganese (Mn) | ≤ 0.35 |
| Carbon (C) | ≤ 0.08 |
| Silicon (Si) | ≤ 0.35 |
| Phosphorus (P) | ≤ 0.015 |
| Sulfur (S) | ≤ 0.015 |
Inconel 718 Investment Casting Process at CFS Foundry
CFS Foundry is a leading manufacturer specializing in investment casting of Inconel 718 material. The process starts with the creation of a precise 3D model for the part, which is approved by the client. This is followed by the making of a high-quality wax pattern using advanced injection molding techniques. The wax pattern is then coated with multiple layers of ceramic material to create a durable shell. After allowing adequate time for the ceramic shell to harden, it undergoes a de-waxing process, where the wax is melted away.
The ceramic shell is then cured in a high-temperature furnace to improve its structural integrity. Once ready, molten Inconel 718 alloy is poured into the shell, which is allowed to cool and solidify. After the metal has adequately solidified, the ceramic shell is carefully broken away, achieving the near-net-shape Inconel 718 casting. The casting then undergoes finishing processes, such as machining and polishing, followed by strict quality checks to ensure it meets all specifications and quality standards.
Why Choose Inconel 718 for Investment Casting?
When it comes to choosing a material for investment casting, Inconel 718 offers a multitude of benefits that make it an excellent choice for a variety of applications. Below are some of the key reasons for selecting Inconel 718:
High-Temperature Stability
One of the biggest advantages of Inconel 718 is its advanced high-temperature stability. This alloy can keep its mechanical strength and dimensional stability even when exposed to temperatures up to 1300°F (704°C). This makes it ideal for aerospace, automotive, and industrial applications where high-temperature resistance is required.
Exceptional Corrosion Resistance
Inconel 718 is highly resistant to a variety of corrosive environments, including those containing acids, salts, and alkalis. Its unique composition of nickel, chromium, and molybdenum provides a protective oxide layer that resists corrosion, making it suitable for marine, chemical, and oil & gas applications.
Superior Strength and Toughness
This alloy not only offers excellent tensile strength but also possesses great yield and fatigue strengths. It’s known for its toughness and ductility, maintaining structural integrity even under extreme stress conditions, making it invaluable in applications such as aerospace components and power turbines.
Versatility
The alloy’s versatile nature allows it to be used in a wide range of applications and industries. Its properties can be further enhanced through heat treatment, enabling customization based on specific requirements.
Easy to Machine and Weld
Despite its high-strength characteristics, Inconel 718 is relatively easy to machine and weld, allowing for more design freedom and reduced production costs when compared to other high-performance materials.
Inconel 718 vs. Inconel 625 for Casting: Key Differences
| Feature | Inconel 718 | Inconel 625 |
|---|---|---|
| Composition | Ni, Cr, Mo, Nb, Ti, Al | Ni, Cr, Mo |
| Temperature Resistance | Up to 1300°F (704°C) | Up to 1800°F (982°C) |
| Corrosion Resistance | Excellent | Exceptional |
| Strength and Toughness | High | Moderate to High |
| Weldability | Good, but can be tricky | Excellent |
| Applications | Aerospace, Oil & Gas, Automotive | Marine, Chemical Processing |
| Post-Treatment | Age-hardening possible | Generally not required |
| Cost | Generally higher | Lower compared to Inconel 718 |
Composition
Inconel 718 contains additional alloying elements like Niobium, Titanium, and Aluminum, making it more complex but beneficial for specific applications compared to the simpler composition of Inconel 625.
Temperature Resistance
While both alloys are designed to operate in high-temperature environments, Inconel 625 can withstand slightly higher temperatures than Inconel 718.
Corrosion Resistance
Inconel 625 has a slight edge in terms of corrosion resistance, making it more suitable for highly corrosive environments like marine and chemical processing industries.
Strength and Toughness
Inconel 718 generally offers higher strength and toughness, especially when age-hardened, making it ideal for applications that demand high strength-to-weight ratios.
Weldability
Inconel 625 is known for its excellent weldability compared to the relatively trickier weldability of Inconel 718.
Applications
Inconel 718 is more common in aerospace and automotive applications due to its high strength, while Inconel 625 is often used in marine and chemical settings because of its superior corrosion resistance.
Post-Treatment
Inconel 718 can be age-hardened to improve its mechanical properties, while Inconel 625 usually doesn’t require post-casting heat treatment.
Cost
Inconel 718 typically costs more due to its complex composition and the additional heat treatments it may require.
In summary, the choice between Inconel 718 and Inconel 625 depends on the specific requirements of your application, including factors like temperature resistance, strength, and cost.
Applications of Inconel 718 Investment Castings
Inconel 718’s unique properties, such as high-temperature stability, excellent corrosion resistance, and superior mechanical strength, make it highly popular for investment casting applications across various industries. Here are some of the primary applications where Inconel 718 investment castings are used:
Aerospace Industry
- Jet Engine Components: Inconel 718 is widely used in manufacturing various jet engine parts, including turbine blades and discs, due to its high-temperature stability and strength.
- Aerostructure Parts: The alloy’s high strength-to-weight ratio makes it suitable for structural components like landing gear parts, wing flaps, and fuselage sections.
Oil & Gas Industry
- Subsea Components: Inconel 718’s excellent corrosion resistance makes it ideal for subsea applications like Christmas tree components and flowline connectors.
- Downhole Tools: The alloy’s ability to withstand high pressures and corrosive environments make it suitable for drilling and wellhead equipment.
Automotive Industry
- Turbocharger Parts: Due to its high-temperature resistance, Inconel 718 is often used in turbocharger turbines and other high-stress, high-temperature components.
- Exhaust Systems: The alloy’s corrosion and heat resistance make it an excellent material for exhaust manifolds and other exhaust system components.
Power Generation
- Gas Turbine Components: In power plants, Inconel 718 is used in high-temperature parts like turbine blades and combustion chambers.
- Nuclear Reactors: Given its excellent mechanical properties and corrosion resistance, it’s used in various parts of nuclear reactors, including control rods and reactor core components.
Industrial Machinery
- Heat Exchangers: The alloy’s ability to resist various types of corrosion makes it a good choice for components in heat exchangers used in chemical and food processing industries.
- High-Pressure Valves: Inconel 718 is commonly used for making high-pressure valves that are used in petrochemical plants, owing to its excellent strength and durability.
Of course, CFS Foundry can also provide custom Inconel 718 investment casting service for other applications.
Contact CFS Foundry for Inconel 718 Investment Casting Solutions
When sourcing high-quality Inconel 718 investment castings, CFS Foundry is the right casting partner for you to work with. With years of expertise in nickel based alloy casting, our company can fulfill your needs for precision components that can withstand extreme temperatures and corrosive environments.
CFS Foundry utilizes the latest techniques in investment casting to ensure high dimensional accuracy and superior surface finishes. Our team of skilled professionals is committed to delivering exceptional customer service throughout the entire process — from design consultation to the finished product. So, if you’re looking for Inconel 718 investment casting services, look no further than CFS Foundry for reliability, quality, and efficiency.
For any inquiries on Inconel 718 investment casting, please send the drawings and 3d files to cathy.sales01@cnool.net directly, we will go back to you within 24 hours!