What is Nickel?

30.10.2020

Varzene Metal



What is Nickel?

Nickel (Ni) is a chemical element with atomic number 28. It is a silver colored and shiny metal. Nickel is a transition metal; it is hard and ductile. Pure nickel powdered to maximize the reactive surface area exhibits significant chemical activity, but larger particles react slowly with air under standard conditions, as an oxide layer forms on the surface and prevents further corrosion. Pure nickel is found in small quantities in the earth's crust and generally in ultramafic rocks, in the interior of nickel-iron meteorites that are not exposed to oxygen outside the atmosphere.

The presence of nickel in meteorites was first detected in 1799 by Joseph-Louis Proust, a French chemist. By analyzing meteorite samples from Argentina, Proust discovered a presence of about 10% nickel with iron in them.

Meteoric nickel is found in combination with iron, which is a reflection of the origin of these elements as the final major products of supernova nucleosynthesis. The iron-nickel mixture is thought to form the outer and inner core of the earth.

Since nickel ores are easily mixed with silver ores, its use has been understood relatively recently. However, the unconscious use of nickel BC. It dates back to the 3500s. Some ancient Chinese manuscripts date back to BCE of "white copper" (cupronickel known as baitong). It suggests that it was used between 1700 and 1400. Cupronickel was exported to England in the early 17th century, but the nickel content of this alloy was not discovered until 1822.

Possibly BC after Chinese cupronickel. In the 2nd century Bactrian kings minted coins of Nickel-copper alloy. Pure nickel coins were also used for the first time in Switzerland in 1881. Canada, the largest nickel producer of the period, always used 99.9% nickel coins from 1922 to 1981, except during the war years. In the 21st century, the rising nickel price caused the coins to change around the world, but some coins made from nickel alloys are still in use today.

In medieval Germany, a red mineral similar to copper ore was found. But when the miners were unable to extract any copper from it, a German myth about preventing it, "Old Nick," was put forward and this gem was inspired by the name Kupfernickel. This ore is now known as nickel, a nickel arsenide.

Nickel was isolated and classified as a chemical element in cobalt mines in Sweden in 1751 by Axel Fredrik Cronstedt, who thought the ore was a copper mineral.
  
Originally the only source of nickel was the rare Kupfernickel. From 1824, nickel was obtained as a byproduct of cobalt blue production. The first large-scale nickel smelting process started with nickel-rich pyrrhotite in Norway in 1848. The introduction of nickel into steel production in 1889 increased the demand for nickel, and New Caledonian nickel deposits, discovered in 1865, supplied most of the world's supply between 1875 and 1915. The discovery of large deposits of meteoric origin in Sudbury / Canada 1883, Norilsk-Talnakh / Russia 1920 and Merensky Reef / South Africa in 1924 made large-scale nickel production possible.

Nickel oxidizes slowly under room conditions and is considered corrosion resistant. Historically, it has been used for iron and brass plating, chemical equipment plating, and the production of some alloys. Approximately 9% of world nickel production is still used for plating. Ferromagnetic is one of four elements. Others are iron, cobalt, and gadolinium. It is especially valuable in alloys. Approximately 68% of the world production is used in stainless steel. The rest is distributed as follows; 10% for nickel-based and copper-based alloys, 7% for alloy steels, 3% for foundries, 9% for plating and 3% for other applications.

Today, Indonesia and Australia are the countries with the largest reserves, with 46% of the world total.

It is estimated that more than 2.7 million tons of nickel is mined annually worldwide, with Indonesia (800,000 tons), Philippines (420,000 tons), Russia (270,000 tons), New Caledonia (220,000 tons), Australia and Canada (180,000 tons). The largest nickel deposits in Europe other than Russia are located in Finland and Greece.

Land-based sources detected worldwide, containing an average of 1% or more nickel, contain at least 130 million tons of nickel. Approximately 60% is in laterites and 40% is in sulphide deposits. In addition, dense sources of nickel in the deep sea are found in manganese shells and nodules that cover large areas of the ocean floor, particularly in the Pacific Ocean.

According to geophysical evidence, most nickel on Earth is believed to be in the Earth's outer and inner cores. Kamacite and taenite are naturally occurring alloys of iron and nickel.

The important ore minerals of nickel are garnierite, a mixture of limonite, pentlandite and natural silicates containing 1-2% nickel.

The Curie temperature of nickel is 355 ° C, so cast nickel is non-magnetic above this temperature. The nickel unit cell is a face-centered cube with a lattice constant of 0.352 nm, giving an atomic radius of 0.124 nm. This crystal structure is resistant to pressures of at least 70 GPa. As a transition metal, Nickel has a relatively high electrical and thermal conductivity. The high compressive strength of 34 GPa foreseen for ideal crystals is never achieved in real bulk material due to the formation and movement of dislocations; it is only achieved in Ni nanoparticles.


Where Do We Use Nickel?

Nickel (Ni) is used in many special and known industrial products, including stainless steel, alnico magnets, coins, rechargeable batteries, electric guitar strings, microphone capsules, plating in plumbing fixtures and special alloys such as permalloy, elinvar and invar. It is used as green color for coating and for glass. However, Nickel is primarily an alloy metal and its main uses are nickel alloys and nickel cast irons, which typically increase tensile strength, toughness and elastic limit. Nickel is widely used in many alloys including brass and bronzes and alloys containing copper, chromium, aluminum, lead, cobalt, silver and gold (Inconel, Incoloy, Monel, Nimonic, etc…).

Nickel is sometimes used instead of decorative silver, as it is resistant to corrosion.
 
Nickel is an excellent alloying agent for some precious metals and is used as a collector of platinum group elements in the fire experiment.

Nickel foam or nickel mesh is used in gas diffusion electrodes for alkali fuel cells.

Nickel and its alloys are often used as catalysts for hydrogenation reactions. Raney nickel, a finely divided nickel-aluminum alloy, is a common form.

Nickel is naturally a magnetostrictive material, meaning that in the presence of a magnetic field, there is a small change in the length of the material. The magnetostriction of nickel is at the level of 50 ppm and is negative, indicating that it is shrinking.

It is used as a binder in the nickel, cementitious tungsten carbide or hard metal industry and 6-12% by weight. Nickel makes tungsten carbide magnetic and adds corrosion resistance to cementitious parts, although its hardness is less than those with cobalt binders.
Approximately 27% of all nickel production is for engineering, 10% for construction, 14% for tubular products, 20% for metal goods, 14% for transportation, 11% for electronics and 4% for other uses. .

Commercially pure or low alloy nickel finds its main application in chemical processing and electronics. Compared to nickel alloys, commercially pure nickel has high electrical conductivity, a high Curie temperature and good magnetostrictive properties. It also has good thermal conductivity. This means it can be used for heat exchangers in corrosive environments. When mechanical parts require excellent corrosion and strong magnetic properties, pure wrought nickel is the best choice among materials with high ductile properties over a wide temperature range.


Which Nickel Alloys Do We Use?

Full solid solubility exists between nickel and copper. The wide solubility ranges between iron, chromium and nickel enable many alloy combinations.

Nickel and nickel alloys are used in a wide variety of applications, the majority of which include Corrosion resistance and Heat resistance. Some of these are Aircraft gas turbines, Steam turbine power plants, Medical applications, Nuclear power systems, Chemical and petrochemical industries.

Nickel-based alloys are used for specific purposes in a number of other applications due to their unique physical properties:

• Low expansion alloys
• Electric resistance alloys
• Soft magnetic alloys
• Shape memory alloys

Corrosion Resistance: Nickel-based alloys offer excellent corrosion resistance against a wide variety of corrosive environments. However, as with all types of corrosion, many factors affect the rate of attack. The corrosive environment itself is the most important factor governing the corrosion of a particular metal.

Heat Resistant Alloys: Nickel-based alloys are used in many applications where they are exposed to harsh environments at high temperatures. Nickel-chromium alloys containing more than about 15% Cr are used to provide both oxidation and carburization resistance at temperatures exceeding 760 ° C.

Low Expansion Alloys: Nickel is known to have a profound effect on the thermal expansion of iron. Alloys can be designed to have very low thermal expansion or to show uniform and predictable expansion at certain temperature ranges. Iron and 36% Nickel alloy (Invar) is the alloy with the lowest expansion of Fe-Ni alloys and almost retains their size during normal changes in atmospheric temperature. Adding cobalt to the nickel-iron matrix produces alloys with a low coefficient of expansion, a constant modulus of elasticity, and high strength.

Electric Resistant Alloys: Various nickel-based or high nickel-containing alloys are used in instruments or heat generating devices to measure electrical properties.

Soft Magnetic Alloys: High nickel alloys (about 79% Ni with 4-5% Mo; the remainder Fe) have high initial permeability and low saturation induction.

Shape Memory Alloys: Metallic materials that show the ability to return to their predefined shapes when subjected to an appropriate heating program are called shape memory alloys. Nickel-titanium alloy 50Ni-50Ti is one of the few commercially important shape memory alloys.


What Are Some Nickel Alloys?

Commercial Nickel and nickel-based alloys are austenitic and are chosen mainly for their resistance to high temperature and water corrosion. Nickel is supplied to nickel alloy manufacturers in powder, pellet or anode form. This leads to a number of alloy modifications with controlled compositions with nickel contents ranging from about 94-100%. These materials are high density, offering magnetic and electronic abilities. Besides their reasonable thermal transfer properties, they offer excellent corrosion resistance to reducing environments. Some commercially important include:

• Nickel 200 (UNS N02200 / 2.4060 / 2.4066) - a nickel used to improve performance in electronic applications.
• Nickel 201 (UNS N02201 / 2.4061 / 2.4068) - excellent resistance to many corrosive environments and simplicity of welding allows this material to be used in many industries.
• Nickel 205 (UNS N02205 / 2.4061) - most commonly used for anodes and grids of electronic valves, magnetostrictive probes, lead wires, transistor housings, battery housings.

It has been found that (Ni-Cu) Nickel-copper alloys show excellent performance in nuclear submarines and various surface ships, have excellent corrosion resistance to chemical environments and seawater. By varying the contents of nickel and copper, a range of alloys with different electrical resistances and Curie points can be created. Some commercially important nickel-copper alloys are Alloy 400 (66% Ni, 33% Cu) and Alloy K-500.

(Ni-Cr) Nickel-chromium and (Ni-Cr-Fe) Nickel-chromium-iron alloys provided higher strength and resistance to higher temperatures. Today they form the basis of both commercial and military power systems. The oldest alloys developed are Alloy 600 (76Ni-15Cr-8Fe) and Nimonic alloys (80Ni-20Cr + Ti / Al).

Some other high temperature alloys:

• Alloy 601 - Lower nickel (61%) content with the addition of aluminum and silicon for improved oxidation and nitriding resistance
• Alloy X750 - Addition of aluminum and titanium for age hardening
• Alloy 718 - Addition of titanium and niobium to overcome stress cracking problems during weld and weld repair.
• Alloy X (48Ni-22Cr-18Fe-9Mo + W) - For aerospace applications
• Waspaloy (60Ni-19Cr-4Mo-3Ti-1.3Al) - For jet engine applications

Some corrosion resistant alloys in the Ni-Cr-Fe system:

• Alloy 625 - The addition of 9% Mo and 3.5% Nb provides both high temperature and water corrosion resistance; Resists pitting and crevice corrosion
• Alloy G30 - Increased molybdenum content in this alloy offers improved pitting and crevice corrosion resistance
• Alloy C22 (Ni-22Cr-6Fe-14Mo-3W) - Superior corrosion resistance in oxidizing acid chlorides, wet chlorine and other severe corrosive environments
• Alloy C276 (17% Mo and 3.5% W) - Good seawater corrosion resistance and excellent pitting and crevice corrosion resistance

Nickel-Chromium-Iron Alloys:
This range of alloys has also found wide use in high temperature petrochemical environments where sulfur-containing raw materials are split into component distillates. It offers not only resistance to chloride-ion stress-corrosion cracking, but also resistance to polythionic acid cracking. Some commercially important alloys:

• Alloy 800 (Fe-32Ni-21Cr) - Resistant to oxidation and carbonization at high temperatures
• Alloy 825 (Fe-42Ni-21.5Cr-2Cu) - Stabilized by the addition of Titanium (0.6 to 1.2%). It also contains molybdenum (3%) for pitting resistance in aqueous corrosion applications. Copper content gives resistance to sulfuric acid
• Alloy 925 - Adding titanium and aluminum to 825 compounds for strengthening through age hardening

Ni-Fe Low Expansion Alloys:
This range of alloys plays a crucial role in both the lamp industry and electronics, where glass-to-metal seals are important in encapsulated components. Some commercially important alloys:

• Alloy 36 (Fe-36Ni) - This alloy has the lowest thermal expansion of any metal from ambient to 230 ° C (450 ° F).
• Alloy 42 (Fe-42Ni) - This alloy has the closest thermal expansion match to alumina, beryl and glassy glass.
• Alloy 52 (Fe-51.5Ni) - This alloy has a thermal expansion very similar to glassy potash-soda-lead glass.