Nickel alloys, also known as high-performance alloys, are metals that contain some nickel in their elemental makeup to improve some of their properties and make them better suited for applications outside their typical wheelhouse. Let’s look at everything to do with nickel alloy including where they’re used, the different types, and their characteristics and physical properties.
What is Nickel Alloy?
If a metal contains nickel as one of its primary elements, it’s classified as a nickel alloy. Some types of nickel alloys are even classed as “superalloys” because, if you compare them to other metals, their oxidation and creep resistance is off the charts and allows them to be used at temperatures of over half their melting points. Although not all superalloys are nickel alloys, the vast majority of them are nickel-based.
Not all metals can be mixed with nickel, but some of the most common elements are iron, chromium, aluminum, molybdenum, copper, cobalt, and titanium. To make nickel alloys, you’d have to follow the same process used for pretty much every other metal alloy. The alloying elements need to be decided on, and their ratios need to be carefully chosen. Once that’s done, the elements are all melted together in something like an arc furnace, which also purifies them, and then the alloy is cast into ingots, and off to be formed using either cold or hot processing.
A Brief History
It’s believed that the first nickel alloy was used in 200 BCE in China. That’s the earliest record available, and the material was referred to as “white copper,” which experts believe was an alloy of nickel and silver. Fast forward to 1751, A. F. Cronstedt, a German scientist, managed to isolate nickel from the niccolite mineral. Copper and zinc were often found in these first nickel alloys, which came to be known as “German silver” and weren’t really used for anything other than ornaments.
After James Riley made an iron-chromium alloy in 1913, W. H. Hatfield figured out that adding nickel to these alloys would make them incredibly corrosion-resistant. This led to the creation of what we now know as austenitic stainless steel .
Nickel Alloy Characteristics
Here are the main characteristics of nickel alloys:
- Corrosion/oxidation resistant
- High strength
- Heat resistance up to 980°C
- Highly ductile, won’t break easily if bent
- Magnetic, can easily be magnetized and demagnetized
- Weldability with various welding methods (although could develop hot or warm cracking and porosity)
- Low thermal conductivity, higher with nickel-copper alloys
- Low electrical conductivity, less than pure copper or silver
- Low thermal expansion coefficient, great for precision
- Varying colors depending on alloying element
It’s generally quite hard to differentiate nickel alloys from other types of metals. Nickel alloys can seem slightly dull when their surface is rough, but when it’s smooth, they can be shiny and reflective.
Types of Nickel Alloys
There are several types of nickel alloys available today. Here’s a list of some of the most common:
| Nickel alloy type | Composition | Characteristics | Common subtypes |
|---|---|---|---|
|
Nickel-Chromium
|
Chromium, molybdenum, iron
|
Oxidation resistance, high mechanical strength, excellent in high-temperature environments, can be hard to cold form due to its quick work-hardening
|
Inconel, 625, 718, and 600
|
|
Nickel-Copper
|
Copper (55–91.5%), iron, tin, manganese
|
Saltwater corrosion and fouling resistance, high strength, performs well in low-temperature environments (its ductility won’t reduce and its strength and hardness can increase), can work harden during cold forming
|
Monel 400, R-405, and K-500
|
|
Nickel-Molybdenum
|
Either chromium or molybdenum
|
Great thermal stability, corrosion- and oxidation-resistance at high temperatures
|
Hastelloy, C-22, and C-276
|
|
Nickel-Iron
|
Iron, nickel (up to 50%), cobalt, small amounts of silicon
|
High ductility, low thermal expansion, corrosion resistance, soft magnetic properties
|
Invar
|
|
Nickel-Chromium
|
High nickel content of around 70%
|
Maintain strength in high temperatures, very good corrosion and oxidation resistance, as well as high electrical resistivity, high melting point of over 1300°C
|
Nichrome
|
|
Nickel-Titanium
|
Nickel, titanium
|
Great corrosion resistance and mechanical strength. This is a shape memory alloy (SMA) that can be formed into a shape above a certain high temperature (the transition temperature). When it cools, the part can be deformed to a certain extent, but when heated back up to the transition temperature, it will resume its original shape. The transition temperature can be adjusted by changing the alloy’s composition
|
Nitinol
|
Types of Nickel Alloys
Properties
In the table below, we list some of the key properties of nickel alloys:
| Property | Type | Benefits | Applications |
|---|---|---|---|
|
Ultimate Tensile Strength [MPa]
|
Inconel 625
|
Excellent corrosion and oxidation resistance, high creep strength
|
Turbine blades and other aerospace components
|
|
Curie Temperature [°C]
|
Invar 36
|
Low thermal conductivity
|
Tooling, dies, cryogenic components
|
|
Coefficient of Linear Thermal Expansion @ @ 93 °C (Annealed) (µm/µm·°C)
|
Invar 36
|
High melting temperature
|
Tooling, dies, cryogenic components
|
|
Thermal Conductivity @ 93 °C (Annealed) (W/m·K)
|
Monel 400
|
Excellent saltwater resistance and low-temperature strength
|
Process vessels, process piping, pumps
|
Nickel Alloy Properties
Chemical Properties
Now that we’ve gone through some of the physical properties of nickel alloys, let’s take a closer look at their chemical properties:
| Type | Corrosion Resistance | Oxidation Resistance | Main Alloying Elements | Magnetic | Heat Resistance [Solidus] °C |
|---|---|---|---|---|---|
|
Inconel 625
|
Very resistant to pitting, chloride ion stress corrosion cracking, and crevice corrosion
|
Highly resistant to oxidation at elevated temperatures
|
Ni – 58% / Cr – 20 to 23% / Fe – 5% / Nb,Ta – 3.15 to 4.15%
|
No
|
1290
|
|
Hastelloy 276
|
Very resistant to pitting, chloride ion stress corrosion cracking, and crevice corrosion
|
Highly resistant to oxidation at elevated temperatures
|
Ni – 57% / Mo – 15 to 17% / Cr – 14.5 to 16.5% / Fe – 4 to 7% / Co – 2.5% / Mn – 1%
|
No
|
1323
|
|
Invar 36
|
Not resistant to corrosion due to high iron content, must be nickel-plated to improve corrosion resistance
|
Not really resistant to oxidation due to its iron content when compared to other nickel alloys
|
Fe – 63% / Ni – 36%
|
Yes
|
1427
|
|
Monel 400
|
Highly resistant to saltwater environments
|
Some Monel grades can have good high-temperature oxidation resistance
|
Ni – 63% / Cu – 28 to 34% / Fe – 2.5% / Mn – 2%
|
No
|
1300
|
|
Nichrome 35-20
|
Not very corrosion-resistant
|
Not very resistant to oxidation
|
Fe – 42% / Ni – 35% / Cr – 20% / Si – 2% / Mn – 1%
|
No
|
1390
|
Nickel Alloy Chemical Properties Table Credit: https://matweb.com/
Physical Property Comparison
In this table, we break down and compare the physical properties associated with some of the most common types of nickel alloys:
| Property | Inconel 625 | Hastelloy 276 | Invar 36 | Monel 400 | Nichrome 35-20 |
|---|---|---|---|---|---|
|
Density [g/cm3]
|
8.44
|
8.89
|
8.05
|
8.8
|
7.9
|
|
Ultimate Tensile Strength [MPa]
|
689–1103
|
601.2–826.7
|
621
|
450–550
|
750
|
|
Curie Temperature [°C]
|
-196
|
-269>26.85
|
279
|
20–50
|
N/A
|
|
Melting Temperature [°C]
|
1290–1350
|
1323–1271
|
1427
|
1300–1350
|
1390
|
|
Electrical Resistivity @ 93 °C (Annealed) [µΩ·cm]
|
132
|
130
|
82
|
54.7
|
104
|
|
Coefficient of Linear Thermal Expansion @ 93 °C (Annealed) (µm/µm·°C)
|
13
|
11.2
|
1.3
|
13.9
|
19
|
|
Thermal Conductivity @ 93 °C (Annealed) (W/m·K)
|
10.8
|
11.1
|
10.15
|
21.8
|
13
|
|
Specific Heat @ 93°C (Annealed) (J/kg·°C)
|
427
|
427
|
515
|
427
|
500
|
Nickel Alloys Physical Property Comparison Table Credit: https://matweb.com/
Nickel Alloys: Applications
Nickel alloys are used in so many sectors. Here are some of their most common applications:
| Application | Description |
|---|---|
|
Aerospace
|
This is one of the most common applications for nickel alloys because of the high operating temperatures that are so common on aerospace equipment. Rocket engine parts and turbine blades are often made from Inconel.
|
|
Chemical processing
|
It’s very common for this sector to require materials that are highly resistant to corrosion environments and substances. Nickel alloys are often used here for things like tanks, piping, and mixing devices.
|
|
Oil & gas
|
Understandably, any materials exposed to oil and gas will need the ability to withstand high temperatures, high pressures, and corrosive environments. That’s why nickel alloys fit the bill. They’re often used to make pumps, pipes, pressure vessels, and heat exchangers.
|
|
Medical
|
Alloys are suitable for medical equipment that goes through regular sterilization at high temperatures or some sort of solvent. They’re also used for orthopedic implants and stents, thanks to the SMA properties
|
|
Electrical/ electronics
|
Some nickel alloys are electrically conductive and resistant to corrosion, making them great for electrical contacts in corrosive environments. Others feature low coercivity, making them perfect for soft magnetic applications like memory storage units or transformers.
|
|
Marine
|
Marine environments can be extremely corrosive and not many alloys can withstand that, especially with prolonged exposure to saltwater and salt spray. Nickel alloys, especially if they’ve got lots of copper in them, are made for the job. They’re often used to make propellers, bilge pumps, and valves.
|
|
Precision Instruments
|
These often need a low coefficient of thermal expansion to reduce temperature effects. An alloy with a low thermal expansion can be used alongside a metal with high thermal expansion, then joined into a bimetal strip that can be used as a temperature switch. Examples include hermetic seals found in X-ray tubes.
|
Leave Your Message
Post time: Jan-16-2026