Iron and Cobalt - Comparison - Properties

This article contains comparison of key thermal and atomic properties of iron and cobalt, two comparable chemical elements from the periodic table. It also contains basic descriptions and applications of both elements. Iron vs Cobalt.

iron and cobalt - comparison

Compare iron with another element

Compare cobalt with another element

Iron and Cobalt – About Elements

Iron

Iron is a metal in the first transition series. It is by mass the most common element on Earth, forming much of Earth’s outer and inner core. It is the fourth most common element in the Earth’s crust. Its abundance in rocky planets like Earth is due to its abundant production by fusion in high-mass stars.

Cobalt

Cobalt is found in the Earth’s crust only in chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal.

Iron in Periodic Table

Cobalt in Periodic Table

Source: www.luciteria.com

Iron and Cobalt – Applications

Iron

Iron is used in numerous sectors such as electronics, manufacturing, automotive, and construction and building. Iron is the most widely used of all the metals, accounting for over 90% of worldwide metal produc0tion. Its low cost and high strength often make it the material of choice material to withstand stress or transmit forces, such as the construction of machinery and machine tools, rails, automobiles, ship hulls, concrete reinforcing bars, and the load-carrying framework of buildings. Since pure iron is quite soft, it is most commonly combined with alloying elements to make steel. Steels are iron–carbon alloys that may contain appreciable concentrations of other alloying elements. Adding a small amount of non-metallic carbon to iron trades its great ductility for the greater strength. Due to its very-high strength, but still substantial toughness, and its ability to be greatly altered by heat treatment, steel is one of the most useful and common ferrous alloy in modern use. There are thousands of alloys that have different compositions and/or heat treatments. The mechanical properties are sensitive to the content of carbon, which is normally less than 1.0 wt%.

Cobalt

Cobalt has been used in many industrial, commercial, and military applications. Cobalt is primarily used in lithium-ion batteries, and in the manufacture of magnetic, wear-resistant and high-strength alloys. Cobalt-based Superalloys. This class of alloys is relatively new. In 2006, Sato et al. discovered a new phase in the Co–Al–W system. Unlike other superalloys, cobalt-base alloys are characterized by a solid-solution-strengthened austenitic (fcc) matrix in which a small quantity of carbide is distributed. While not used commercially to the extent of Ni-based superalloys, alloying elements found in research Co-based alloys are C, Cr, W, Ni, Ti, Al, Ir, and Ta. They possess better weldability and thermal fatigue resistance as compared to nickel based alloy. Moreover, they have excellent corrosion resistance at high temperatures (980-1100 °C) because of their higher chromium contents. Several cobalt compounds are oxidation catalysts. Typical catalysts are the cobalt carboxylates (known as cobalt soaps). They are also used in paints, varnishes, and inks as “drying agents” through the oxidation of drying oils.

Iron and Cobalt – Comparison in Table

Element	Iron	Cobalt
Density	7.874 g/cm3	8.9 g/cm3
Ultimate Tensile Strength	540 MPa	800 MPa
Yield Strength	50 MPa	220 MPa
Young’s Modulus of Elasticity	211 GPa	209 GPa
Mohs Scale	4.5	5
Brinell Hardness	490 MPa	800 MPa
Vickers Hardness	608 MPa	1040 MPa
Melting Point	1538 °C	1495 °C
Boiling Point	2861 °C	2927 °C
Thermal Conductivity	80.2 W/mK	100 W/mK
Thermal Expansion Coefficient	11.8 µm/mK	13 µm/mK
Specific Heat	0.44 J/g K	0.42 J/g K
Heat of Fusion	13.8 kJ/mol	16.19 kJ/mol
Heat of Vaporization	349.6 kJ/mol	376.5 kJ/mol