Nickel exists as both a naturally occurring pure substance and an engineered mixture of metals. It is fundamentally a distinct element found on the periodic table, but it is rarely used in its pure state for commercial applications. Instead, its unique properties make it an ideal partner for other materials, leading to its widespread use as a component in various engineered mixtures. This transformation from a pure metal to an alloy makes nickel highly versatile in modern technology.
Nickel’s Identity as an Element
Nickel is defined scientifically as a pure metal, a transition element with an atomic number of 28. In its elemental state, it is a silvery-white, lustrous metal that often displays a slight golden tint. Its inherent properties include being hard, malleable, and ductile.
Pure nickel is one of the few elements that is ferromagnetic at or near room temperature, a characteristic it shares with iron and cobalt. This magnetic property is retained up to its Curie point, which is approximately 355°C (671°F). It also possesses a moderately high melting point of about 1453°C, which contributes to its stability in high-temperature processes.
Why Nickel Becomes an Alloy
While pure nickel is useful, it is most often combined with other elements to form alloys that possess superior performance characteristics. An alloy is a mixture of two or more elements engineered to enhance specific properties of the base material. The primary purpose of alloying nickel is to significantly increase its strength and resistance to various forms of degradation.
Nickel is particularly effective at enhancing corrosion resistance, especially when facing harsh chemical environments, such as exposure to acids and bases. This protection occurs because nickel forms a thin, dense, and stable oxide layer on its surface that prevents the underlying metal from reacting further. Alloying with elements like chromium and molybdenum also improves the material’s ability to withstand high temperatures and mechanical stress.
These engineered mixtures are valued for their superior high-temperature stability and creep resistance—the tendency of a solid material to slowly deform under mechanical stress. For instance, adding nickel to iron creates austenitic stainless steel, which maintains its tough, ductile structure. This ability to blend seamlessly while imparting strength makes nickel an indispensable component in high-performance metals often referred to as superalloys.
Common Uses of Nickel in Everyday Life
The exceptional properties nickel imparts to alloys translate directly into numerous practical applications encountered daily. One of the most technologically relevant uses is in energy storage devices, specifically rechargeable batteries. Nickel is a component in both Nickel-Metal Hydride (NiMH) and modern Lithium-ion batteries, where it helps deliver higher energy density and greater storage capacity.
The metal’s resistance to wear and corrosion is widely exploited in protective coatings through electroplating. A thin layer of nickel is often applied to items like plumbing fixtures, faucets, and various hardware to provide a durable, aesthetically pleasing finish that resists tarnishing. This same durability is why nickel, or nickel-plated steel, is used in modern coinage, ensuring currency can withstand decades of circulation.
Beyond electronics and plating, nickel is a significant component in stainless steel, which is omnipresent in kitchenware, medical equipment, and architectural construction. Additionally, it is used in certain types of jewelry and fasteners, where it contributes to the material’s hardness, luster, and general resistance to corrosion.