SAE AMS 5387 Alloy – Composition, Properties, and Uses

In industries such as aerospace, defense, energy, and high-performance engineering, specialized alloys are essential to withstand extreme conditions. One of the widely recognized specifications in this field is SAE AMS 5387, which defines a cast cobalt-based alloy known for its exceptional resistance to heat, wear, and corrosion. This alloy is often chosen for applications where conventional steels or nickel-based alloys cannot provide sufficient durability.

This article provides a complete guide to SAE AMS 5387 alloy, including its composition, mechanical and physical properties, advantages, and industrial applications.

What is SAE AMS 5387 Alloy?

SAE AMS 5387 is a specification issued by SAE International, covering a cobalt-chromium-tungsten alloy produced primarily in cast form. This alloy is highly resistant to oxidation, high-temperature corrosion, and mechanical wear, making it a preferred material for turbine components, engine parts, and other high-stress environments.

Its unique combination of heat resistance and strength makes AMS 5387 a reliable choice for critical applications where safety and performance cannot be compromised.

Chemical Composition of SAE AMS 5387 Alloy

The composition of AMS 5387 is carefully designed to achieve resistance to oxidation and wear at elevated temperatures. A typical chemical composition includes:

• Cobalt (Co): Balance

• Chromium (Cr): 25 – 33%

• Tungsten (W): 3.5 – 7%

• Nickel (Ni): ≤ 3%

• Molybdenum (Mo): ≤ 1%

• Carbon (C): 0.20 – 0.35%

• Iron (Fe): ≤ 3%

• Silicon (Si): ≤ 2%

• Manganese (Mn): ≤ 2%

This high chromium content provides corrosion resistance, while tungsten improves wear resistance and strength at high temperatures.

Mechanical Properties

The mechanical properties of AMS 5387 alloy make it suitable for high-stress applications:

• Tensile Strength: Approx. 900 – 1100 MPa (depending on heat treatment)

• Yield Strength: Approx. 500 – 700 MPa

• Elongation: 5 – 10%

• Hardness: 35 – 45 HRC

• Density: ~8.3 g/cm³

These properties ensure the alloy can handle demanding environments without deformation or premature failure.

Physical Properties

• Melting Range: 1380 – 1415°C

• Thermal Expansion Coefficient: Moderate, ensuring dimensional stability at high temperatures

• Oxidation Resistance: Excellent, even in high-temperature oxidizing atmospheres

• Wear Resistance: High, suitable for applications involving friction and mechanical contact

Key Characteristics of SAE AMS 5387

1. High-Temperature Strength – Retains mechanical properties at elevated temperatures.

2. Corrosion and Oxidation Resistance – Performs well in aggressive environments, including oxidizing gases.

3. Wear Resistance – Durable under conditions of friction and mechanical contact.

4. Castability – Produced in complex shapes using precision casting techniques.

5. Versatility – Suitable for aerospace, energy, and defense industries.

Advantages of AMS 5387 Alloy

• Long service life under extreme conditions

• Reliable performance in corrosive and oxidizing environments

• Strong resistance to mechanical wear

• Suitable for high-temperature applications

• Lower maintenance requirements due to durability

Limitations

• Higher cost compared to standard steels and nickel alloys

• Lower ductility, making it less suitable for applications requiring high toughness

• Limited machinability due to hardness and wear resistance

Applications of SAE AMS 5387 Alloy

Aerospace Industry

• Gas turbine blades and vanes

• Combustion chamber components

• Engine seals and wear rings

Power Generation

• Turbine components in steam and gas power plants

• Heat exchanger parts exposed to hot gases

Defense and Military

• Jet engine components for military aircraft

• High-performance propulsion systems

Industrial Engineering

• Furnace components

• Chemical processing equipment exposed to high-temperature corrosion

Comparison with Other Alloys

• AMS 5387 vs Stainless Steel: AMS 5387 provides superior high-temperature performance but is more expensive.

• AMS 5387 vs Nickel-Based Alloys: Nickel alloys excel in certain corrosion conditions, but cobalt-based AMS 5387 offers better wear resistance.

• AMS 5387 vs Tool Steels: Tool steels have high hardness but cannot withstand the same levels of heat and oxidation resistance as AMS 5387.

Standards and Specifications

SAE AMS 5387 is part of a family of aerospace material specifications. It ensures:

• Consistent chemical composition

• Verified mechanical and physical properties

• Compliance with aerospace and defense requirements

Other related specifications may include AMS 5383 and AMS 5390, which cover similar cobalt-based alloys for different casting methods.

Market Demand and Supply

With the growing demand for efficient gas turbines, advanced jet engines, and high-performance industrial equipment, the use of AMS 5387 alloy is expanding. Reliable suppliers like sasaalloy provide certified cobalt-based alloys that meet SAE standards, ensuring quality and consistency. By working with sasaalloy, industries can source materials capable of withstanding the toughest operating conditions.

Conclusion

SAE AMS 5387 alloy is a high-performance cobalt-based alloy designed for extreme environments where heat, wear, and corrosion resistance are critical. Its composition, dominated by cobalt, chromium, and tungsten, provides an exceptional balance of properties that make it ideal for aerospace, power generation, defense, and industrial applications.

Although it comes at a higher cost, AMS 5387 delivers long-term value by reducing maintenance, enhancing safety, and ensuring reliability under demanding conditions. For engineers and decision-makers seeking a durable material for critical systems, SAE AMS 5387 remains one of the most trusted alloys available today.