Difference Between Inconel and Monel

The key difference between Inconel and Monel is that Inconel is a nickel–chromium-based alloy, whereas Monel is a nickel-copper based alloy.

Inconel and Monel are common tradenames in industry. They are two groups of superalloys which have alloys with extreme corrosion resistance. However, both types are highly expensive as well. It is because of their expensive production process.

CONTENTS

1. Overview and Key Difference
2. What is Inconel 
3. What is Monel
4. Similarities Between Inconel and Monel
5. Side by Side Comparison – Inconel vs Monel in Tabular Form
6. Summary

What is Inconel?

Inconel is a tradename of a group of superalloys. It contains austenitic nickel and chromium based superalloys. Manufacturers have specifically optimized these alloys in order to meet the toughest conditions during usage. In other words, Inconel has a high tolerance towards extreme heat and can keep its tensile strength at high temperatures without any change.

However, this material is expensive. In addition to tolerating extreme heat, these alloys are oxidation-corrosion resistant. When heated, this material forms a thick and stable oxide layer. And, this oxide layer can protect the surface of the alloy from further attack from heat.

Inconel is preferable over stainless steel in heat treat applications, rapid temperature changes, when exposure to salt water is required, in jet engines, etc. Moreover, this material is common in gas turbines blades, seals, high-temperature fasteners, etc.

What is Monel?

Monel is a tradename for a group of nickel-copper alloys. These alloys contain nickel predominantly with copper and few other substances including iron, manganese, carbon and silicon. The nickel content typically ranges from 52 to 67%.

Besides, this alloy is stronger than pure nickel. Moreover, it is resistant to corrosion by various agents, even by flowing sea water. The fabrication methods include hot- and cold-working, machining, and welding. More importantly, this alloy is highly expensive; for example, piping with Monel rather than carbon steel is more than 3 times expensive. Therefore, the usage of this alloy is limited.

Considering the usage, the applications of this alloy are in the field of aerospace applications, oil production, refining, marine applications, musical instruments, etc. Several grades of Monel include Monel 400, Monel 401, Monel 404, etc.

What are the Similarities Between Inconel and Monel?

• Inconel and Monel are highly corrosion resistant.
• Moreover, they are highly expensive.
• Also, both contain nickel as the predominant material.

What is the Difference Between Inconel and Monel?

Inconel is a tradename of a group of superalloys while Monel is a tradename for a group of nickel-copper alloys. Theerefore, the key difference between Inconel and Monel is that Inconel is a nickel-chromium-based alloy, whereas Monel is a nickel-copper based alloy. Moreover, the maximum nickel content in Inconel is around 72% while the maximum nickel content in Monel is around 67%.

When considering the applications, Inconel usage is common in gas turbines blades, seals, high-temperature fasteners, etc. whereas Monel is used in aerospace applications, oil production, refining, marine applications, musical instruments, etc. So, we can consider this too as a difference between Inconel and Monel.

Summary – Inconel vs Monel

Inconel and Monel are two important tradenames that name groups of alloys. The key difference between Inconel and Monel is that Inconel is a nickel-chromium-based alloy, whereas Monel is a nickel-copper based alloy.

Reference:

1. “Monel (Nickel-Copper Alloy) Facts, Composition, Properties, Uses.” Chemistry Learner, 26 Nov. 2018, Available here.

Image Courtesy:

1. “Dog tags” By Postdlf (CC BY-SA 3.0) via Commons Wikimedia
2. “Inconel 718” By Ascaron – Own work (CC BY-SA 3.0) via Commons Wikimedia