An alloy is a metal created by combining two or more metallic elements. The alloying process enhances the properties of each of the metals, resulting in a more useful end product. People typically produce alloys to increase corrosion resistance, hardness or tensile strength or lower melting point.
Superalloys are high-performance alloys that exhibit many of the same characteristics but at a higher level. They feature superior corrosion and heat resistance, excellent surface stability, exceptional mechanical strength and strong creep resistance at elevated temperatures. Consequently, superalloys will deliver better results than standard alloy materials.
The Different Types of Superalloys
While superalloys can consist of a wide range of materials, nickel-based products are the most common. Examples of nickel-based and other superalloys include:
- Inconel: Inconel refers to a group of alloys composed primarily of a nickel-chromium combination. Inconel alloys offer excellent corrosion and heat resistance, making them suitable for high-temperature applications.
- Monel: The Monel family of superalloys consists of products featuring a combination of nickel and copper. They offer superior corrosion resistance, especially to rapidly flowing seawater. They also provide good thermal resistance at high temperatures.
- Hastelloy: The Hastelloy group of nickel-based superalloys also provides excellent corrosion and heat resistance. The various Hastelloy products include combinations such as nickel-molybdenum-chromium-tungsten and nickel-chromium-iron-molybdenum.
- Incoloy: This nickel-iron-chromium alloy also contains traces of copper, titanium and molybdenum. Incoloy provides excellent corrosion resistance in oxidizing and reducing environments.
- Cobalt-based superalloys: Cobalt is another base material found in many superalloys. Cobalt-based materials typically don’t match nickel-based superalloys in strength or stability, but they offer better heat resistance. They function best in high-heat, low-stress environments. The cobalt content ranges from 35% to 65%, with nickel and chromium comprising the rest.
- Iron-based superalloys: These superalloys can provide a more cost-effective alternative to nickel and chromium for applications requiring heat and creep resistance. They also offer good resistance to wear and tear. The iron content in these materials can range from 32% to 67%. The rest typically consists of chromium and nickel.
How Superalloys Are Used
Superalloys have many applications in industrial settings. For instance, because of its excellent corrosion and heat resistance, Inconel is a popular choice for manufacturing parts such as tubings, valves, fittings and nuts and bolts for ocean-going vessels, jet engines and turbines. Incoloy applications include chemical processing, oil and gas recovery and pollution control. Companies in the petrochemical industry often use pipes and valves manufactured from Hastelloy because of its resistance to oxidizing and reducing agents.
The automotive industry is another significant consumer of superalloys. They choose these alloys because of their ability to maintain strength at extreme temperatures. Because of their lighter weight, superalloys can also help to improve vehicle fuel efficiency.
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SPC Can Electroplate All Types of Superalloys
Electroplating can enhance the strength as well as the heat and corrosion resistance of many superalloys. Although the process is challenging, a handful of metal finishing companies, including SPC, can deliver reliable, consistent results. Contact us to learn more about the plating of superalloys and get a free project quote today.