Elgiloy U-shaped springs are high-performance spring energizers commonly used in demanding sealing applications. These springs are designed to provide a consistent and controlled force, ensuring reliable sealing in extreme environments. The use of Elgiloy, a cobalt-based superalloy, enhances their performance due to its excellent corrosion resistance, high fatigue strength, and stability in extreme temperatures.
This document provides a comprehensive analysis of Elgiloy U-shaped springs, covering their material properties, design, manufacturing processes, applications, advantages, and comparison with other materials like stainless steel and beryllium copper.
2. Material Properties of Elgiloy
Elgiloy is a high-performance cobalt-chromium-nickel alloy known for its unique combination of mechanical strength, corrosion resistance, and fatigue resistance. Below are the key properties:
2.1 Composition of Elgiloy
Cobalt (Co): ~40%
Chromium (Cr): ~20%
Nickel (Ni): ~15%
Iron (Fe): ~10%
Molybdenum (Mo): ~7%
Manganese (Mn): ~2%
2.2 Key Characteristics
High tensile strength: Capable of withstanding extreme forces.
Excellent corrosion resistance: Performs well in acidic, saline, and high-temperature environments.
Non-magnetic: Ideal for aerospace and medical applications.
Fatigue resistance: Long-lasting performance under dynamic loads.
Wide temperature stability: Suitable for cryogenic (-200°C) to high-temperature (600°C) applications.
3. Design and Functionality
3.1 U-Shaped Spring Structure
Die U-shaped configuration allows for controlled deflection and uniform force distribution.
Each coil provides independent deflection, ensuring a near-constant force over a wide range of compression.
This structure is ideal for high-precision seals that require consistent energization.
3.2 Working Principle in Seals
These springs are used inside polymer-based federunterstützte Dichtungen (e.g., PTFE, PEEK, or UHMWPE).
When compressed, the spring applies a uniform load against the sealing lips, ensuring optimal sealing performance even under varying pressure and temperature conditions.
4. Manufacturing Process
4.1 Wire Forming
Precision cold-forming techniques are used to shape the Elgiloy wire into the required U-shaped configuration.
The process ensures uniform coil spacing and dimensional accuracy.
4.2 Heat Treatment
The formed springs undergo a heat treatment process to optimize mechanical properties and stress relief.
Ensures consistent load-deflection characteristics and durability.
4.3 Surface Treatments
Electropolishing: Enhances corrosion resistance and reduces surface roughness.
Passivation: Removes contaminants and improves oxidation resistance.
5. Applications
5.1 Aerospace Industry
Used in fuel, hydraulic, and environmental sealing systems for aircraft and spacecraft.
Provides reliable performance under extreme pressures and temperature fluctuations.
5.2 Medical Devices
Commonly used in implantable medical devices, surgical instruments, and pharmaceutical processing equipment.
Non-magnetic and corrosion-resistant properties make it ideal for biocompatible applications.
5.3 Chemical and Oil & Gas Industry
Used in aggressive chemical environments, high-pressure valves, pumps, and process equipment.
Resists degradation from acids, hydrocarbons, and extreme temperatures.
5.4 Cryogenic and High-Temperature Applications
Performs well in cryogenic conditions (-200°C) and high temperatures (up to 600°C).
Used in liquid natural gas (LNG) systems, space applications, and nuclear industry sealing.
6. Advantages Over Other Materials
Property
Elgiloy
Stainless Steel 316
Beryllium-Kupfer
Korrosionsbeständigkeit
Excellent
Moderate
Good
Strength
High
Moderate
Moderate
Ermüdungswiderstand
Excellent
Good
Good
Temperaturbereich
-200°C to 600°C
-150°C to 400°C
-100°C to 350°C
Non-Magnetic
Yes
No
No
Biocompatibility
Yes
No
No
7. Performance Characteristics
7.1 Load-Deflection Behavior
The U-shaped spring provides a nearly constant force over a wide deflection range.
Ideal for applications requiring consistent and predictable energization.
7.2 Compression and Recovery
Retains shape and elasticity even after prolonged compression cycles.
Unlike traditional coil springs, the U-shaped design prevents force decay over time.
7.3 Electrical Conductivity
Can be used for electrical grounding and EMI shielding in electronic and aerospace applications.
Provides stable electrical contact under mechanical stress.
8. Conclusion
Elgiloy U-shaped springs are high-performance spring energizers designed for extreme sealing applications. Their superior corrosion resistance, fatigue strength, and ability to maintain a constant force make them indispensable in aerospace, medical, and chemical industries. Compared to stainless steel and beryllium copper, Elgiloy offers unparalleled durability and reliability, ensuring long-term performance in critical environments.
