ThePipingMart Blog Grades AMS 4118 Aluminum Alloy – Composition, Properties, and Uses

AMS 4118 Aluminum Alloy – Composition, Properties, and Uses

AMS 4118

AMS 4118 is a kind of aluminium alloy commonly used in the aerospace industry. Its unique physical and mechanical properties make it popular for various applications. This blog post will delve deeper into the composition, physical properties, mechanical properties, uses, hardness, and heat treatment of AMS 4118. Read on to discover everything you need to know about this aluminium alloy.

What is AMS 4118?

AMS 4118 is a high-strength aluminium alloy frequently used in aerospace due to its excellent strength, toughness, and corrosion resistance. This alloy is commonly used to manufacture structural components for aircraft, such as wing skins and frames, and structural components for space vehicles. In addition to its strength and durability, AMS 4118 is also known for its ability to be easily welded and machined, making it a popular choice for manufacturers looking for a high-performance material that can be easily processed. Whether you’re building an aeroplane or a satellite, AMS 4118 is a top choice for high-strength components that can withstand the rigours of flight and space travel.

AMS 4118 Composition

AMS 4118 is an aluminium alloy comprising copper, magnesium, iron, manganese, and silicon. The precise composition of AMS 4118 varies depending on the manufacturer, but it generally contains 4.4-5.0% copper, 1.5-2.0% magnesium, 0.8-1.3% iron, 0.3-0.7% manganese, and 0.4-0.8% silicon. This combination of elements gives it unique properties that make it suitable for high-stress applications.

AMS 4118 Physical Properties

AMS 4118 has a density of 2.80 g/cm³, making it a relatively lightweight material. It has a melting point of 582-652°C, which is relatively low compared to other metals. Its thermal conductivity ranges from 127-141 W/(m·K), while its coefficient of thermal expansion is 23.8 x 10^-6/K. It also has excellent corrosion resistance and is highly resistant to stress corrosion cracking.

AMS 4118 Mechanical Properties

AMS 4118 has outstanding mechanical properties, including exceptional strength, stiffness, and toughness. Its ultimate tensile strength is around 590 MPa, while its yield strength is approximately 510 MPa. Its elongation at break is about 5%, while its modulus of elasticity is around 70 GPa. It also has excellent fatigue resistance and can withstand repeated stress cycles without failure.

AMS 4118 Uses

AMS 4118 is used in various applications, including aircraft components, marine equipment, and sporting goods. Thanks to its high strength-to-weight ratio, it is frequently used to construct aircraft wings, fuselage sections, and bulkheads. It is also used to construct propeller blades, helicopter hubs, and landing gear components. In the marine industry, it is used to make boat hulls, masts, and rigging components, while it is also found in bicycle frames, skis, and other sporting equipment.

AMS 4118 Hardness

AMS 4118 is a relatively hard material, with a Brinell hardness of approximately 180. The hardness of AMS 4118 can be further enhanced by subjecting it to various heat treatment processes.

AMS 4118 Heat treatment

AMS 4118 can be heat-treated to further enhance its mechanical properties. The most common heat treatment process for AMS 4118 is solution heat treatment, where the alloy is heated to a specific temperature and then quenched to improve its strength and hardness. Other heat treatment processes, such as precipitation hardening, can also be used to improve the properties of AMS 4118.


AMS 4118 is a popular aluminium alloy with exceptional physical and mechanical properties, making it an ideal material for high-stress applications. Its unique composition, lightweight nature, and excellent corrosion resistance have made it one of the most sought-after materials in the aerospace industry. It is also used in other applications, including marine equipment and sporting goods. With its high strength-to-weight ratio, it is widely regarded as one of the most versatile aluminium alloys available today.

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