Nickel

7-45 usd/kg
Circularity potential
High
Strength
Very high
Production energy
Very high
Stiffness
Very high
Embodied CO2
Very high
Density
Extreme

Nickel is a bright silvery metal with outstanding corrosion resistance, chemical resistance and high temperature endurance. Recognisable as the coating on glass mirrors, the majority goes into the production of stainless steel and alloy steel. It is also an important alloy with non-ferrous metals, such as copper and aluminium. On top of this, it is used in batteries and as a coating in metal plating.

Nickel superalloys, such as with chromium (Cr) and copper (Cu), have exceptional mechanical properties and chemical resistance at very high temperature. They are utilised in the most demanding marine, chemical, raw material processing, food manufacturing and aerospace applications.

Nickel production is energy intensive and results in significant CO2 emissions. The amount depends on the source of nickel and type of ore, with ores coming from remote and inaccessible areas requiring a great deal of infrastructure to be built. As all of the more accessible nickel deposits and relatively lower energy demand ores are extracted, companies are inevitably moving on to more challenging sites, which will lead to an increased embodied energy and carbon footprint.


Sustainability concerns
Non-renewable ingredients
Raw material generates polluting by-products


Nickel-chromium superalloys (Ni-Cr), often referred to by the trade name Inconel, combine excellent low and high temperature strength with superior resistance to corrosion. At high temperature they form a protective oxide layer that is very stable and prevents corrosion. They are used for some of the most demanding applications.

Their impressive mechanical properties make them challenging to form – they resist deformation at hot working temperatures. Cold working is possible but requires relatively high forces. They can be welded, with some grades optimised to allow the fabrication of complex parts such as required for aerospace and manufacturing industries.

– Inconel 600, nickel-chromium 600 (UNS N06600, 2.4816), is made up of 72% Ni with 14-17% Cr, Fe, C, Mn and other elements. It has very good resistance to corrosion and retains its mechanical properties at low and high temperatures. It is utilised extensively in the chemical industry, high performance electronics and nuclear reactors. It can be formed by cold and hot working to achieve very high tensile strengths (1,517 MPa). It has similar machinability to type 304 stainless steel.

– Inconel 601, nickel-chromium 601 (UNS N06601, 2.4851), is made up of 58-63% Ni with 21-25% Cr, Al, Cu, Mn and other alloys. It is specially designed to resist high temperature oxidising atmospheres and is used in manufacturing raw materials, such as metal and glass, and chemical processing.

– Inconel 625, nickel-chromium alloy 625 (UNS N06625, 2.4856), is made up of 58% Ni with 20-23% Cr. Fe, Mo, C and many other elements make up the remainder. It is a high strength alloy used for seawater applications such as wire rope, propellor blades, submarine parts and sheathing for underwater cables. Its high tensile, creep and thermal-fatigue strength are utilised in aerospace applications such as ducting, exhausts, engine parts, tubing and electronics.

– Inconel 690, nickel-chromium 690 (UNS N06690, 2.4642), is made up of 58% Ni with 27-31% Cr, Fe, Cu, Mn and other alloys. This high-chromium nickel alloy has excellent corrosion resistance coupled with high strength at elevated temperatures. It is used for demanding industrial applications such as pickling stainless steel and reprocessing nuclear fuels. It is manufactured into parts using the same techniques as for alloy 600.

– Inconel 718, nickel-chromium 718 (UNS N07718, 2.4668), comprises 50-55% Ni, 17-21% Cr, Fe and many other alloys. It is age-hardenable and readily fabricated into complex parts. It has excellent welding characteristics. This advantage, combined with its excellent mechanical properties, mean it is useful for many applications, casings and sheet metal parts for aircraft, gas turbine engines, cryogenic tanks and electronics.


Design properties
Cost usd/kg
40-45
Embodied energy MJ/kg
147-485
Carbon footprint kgCO2e/kg
13-45
Density kg/m3
8110-8470
Tensile modulus GPa
205-214
Tensile strength MPa
550-1103
Shear modulus GPa
80
Hardness Mohs
4.5
Brinell hardness HB
175-240
Poissons ratio
0.28-0.32
Thermal expansion (µm/m)/ºC
10.4-14.06
Melt temperature ºC
1354-1413
Thermal conductivity W/mK
11.2-14.9
Temperature min-max °C
"-200 to 1200"
Thermal
conductive
Electrical
conductor
Electrical resistivity µΩ⋅m
1.03-1.15