ThePipingMart Blog Grades AMS 4783 Cobalt Alloy – Composition, Properties, and Uses

AMS 4783 Cobalt Alloy – Composition, Properties, and Uses

AMS 4783

When choosing a suitable material for a specific application, it is essential to consider various properties to ensure optimal performance. AMS 4783 is a common material used across industries due to its outstanding properties. If you are in the aerospace or defence industry, you are likely familiar with AMS 4783 and its unique features. But if you are new to this material, read on to learn more about its composition, physical properties, mechanical properties, hardness, and heat treatment.

What is AMS 4783?

If you’ve ever encountered the term “AMS 4783”, you may wonder what it means. AMS 4783 is a specific type of aerospace alloy used in high-performance jet engine applications. This alloy is known for its excellent strength and resistance to high temperatures, making it a popular choice for critical engine components. The material is also well-suited for welding and other fabrication techniques, making it a versatile option for various aerospace applications. So if you ever encounter a product or component that mentions AMS 4783, you can rest assured that it has been engineered to meet the rigorous demands of modern aviation.

AMS 4783 Composition

AMS 4783 is a nickel-based alloy that includes chromium, cobalt, tungsten, and molybdenum. Its chemical composition is as follows: Nickel (57-60%), Chromium (19-21%), Cobalt (13-15%), Molybdenum (2.5-3.5%), and Tungsten (2.5-3.5%). The alloy also contains trace amounts of carbon, manganese, silicon, iron, and sulfur. This unique composition offers excellent corrosion resistance and heat resistance.

AMS 4783 Physical Properties

AMS 4783 has a density of 0.307 lbs/in3 (8.5 g/cm3) and a melting point of 2550-2635°F (1400-1446°C). It also has a thermal conductivity of 78.1 BTU-in/hr-ft2-°F (11.3 W/m-°K) and a specific heat of 0.109 BTU/lb-°F (455 J/kg-°K). Regarding electrical conductivity, it has a resistivity of 385 ohm-cir mil/ft (6.39 microohm-cm) and a magnetic permeability of 1.001.

AMS 4783 Mechanical Properties

AMS 4783 exhibits excellent mechanical properties, including high tensile strength, fatigue, and creep resistance. Its ultimate tensile strength is about 150 ksi (1034 MPa), and its yield strength is around 120 ksi (827 MPa). The alloy also has a high modulus of elasticity of 31.6 Msi (218 GPa) and good impact strength. These properties make AMS 4783 suitable for use in high-temperature applications.

AMS 4783 Hardness

AMS 4783 has a typical hardness of 42 HRC (Rockwell C). This relatively high hardness level shows the material’s ability to resist deformation under stress. The hardness can be adjusted by applying different heat treatments, which allows for effective customization of the material’s properties.

AMS 4783 Heat Treatment

Heat treatment is a process to improve or modify a material’s physical and mechanical properties. AMS 4783, like many other nickel-based alloys, responds well to heat treatment. The most common heat treatment used for AMS 4783 is solution heat treatment followed by a precipitation treatment. Solution heat treatment involves heating the alloy to a specific temperature to dissolve elements in the material and then cooling it to achieve a homogeneous structure. Precipitation treatment consists in heating the material to a particular temperature to allow the formation of a uniform, fine precipitate. The heat treatment improves the material’s strength, flexibility, and other properties.


AMS 4783 is a nickel-based alloy that offers exceptional properties and is widely used in the aerospace and defence industries. Its unique chemical composition and remarkable physical and mechanical properties make it an excellent choice for high-temperature applications. Understanding the composition, physical and mechanical properties, hardness, and heat treatment of AMS 4783 can help you make informed decisions when selecting materials for your specific application.

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