Carbides are combinations of special metals and carbon to form very hard materials greater than that of hardened steel. They are therefore used in applications requiring extreme strength such as machine tool bits, drilling and mining operations.
Mechanical Properties of Carbides
The mechanical properties of carbides are determined in terms of;
- Hardness at varying temperatures
- Hardness measured at room temperatures
- Compression strength in megapascals
- Transverse rapture force in megapascals
Tantalum carbide exhibits a hardness of 1570 Hv (Vickers hardness) at 200 c and 800 Hv at 7300c, as compared to titanium carbide which exhibits a hardness of 2930 Hv at 200c and 640 Hv at 7300c. Different carbides will show varying mechanical properties
Industrial Applications of Carbides
The special combination of physical and structural properties of carbides gives them special industrial uses. These include:
- Resistance to abrasion which is very high and they easily outlast hard steel grades.
- Resistance to deflection: Compared to steel bars of the same grades, carbides have an elasticity modulus of up to three times more which equals to one third deflection compared to the steel bars.
These are properties which make these carbide chemicals very effective in extreme temperature and pressure conditions such as in drilling and machine tool bits. Carbide balls are also used as milling agents due to their hardness in Attritor mills. Some Specific carbide chemicals include;
It has very strong covalent bonds in their structure producing a hard and brittle material. It has very high degree of stability and resistance thus used to enhance performance of very hard metal machining tools.
Chromium Carbide Powder
Chromium carbide powder used in manufacture of bearing seals, valve seats and its ability to resist corrosion makes it suitable in applications where chemical corrosion is likely. It is also used as a heated spray for protecting vulnerable metal surfaces.
Ferrotitanium Carbide is effective in solving many wearing out problems and enabling re use of worn out and reconditioned machine tool pieces. It is easily re-machined and hardened through a simple heat treatment.
Hafnium Carbide Powder
This compound is used in production of hard coatings such as plasma spraying. The power form is used in applications requiring high surface areas such as in fuel cells and solar panels applications.
With a chemical formula of Sic, it has been used for a long time as an abrasive substance therefore used in the manufacture of sand papers, grinding wheels and cutting tools in industry. It is also used in heating elements in furnaces and refractory linings.
Denoted as carbon titanium nitride powder, it is used in hardening and protection of cutting and sliding surfaces. It is also used in decorative purposes due to the gold like appearance as well as a non toxic cover for medical implants.
Titanium Carbide Powder
It is used as an additive in production of manufacturing tools, and hard ceramics.
Tungsten Carbide Powder
Ha s a number of industrial applications due to its hardness and tough nature. The powder has varying grain size and using a binder material, engineers can develop a variety of very hard components used in manufacture of machine tools components. The tungsten carbide powder can be cemented and used in manufacture of very hard gears and special tools used in the mining and oil exploration sectors.
Vanadium Carbide Powder
Recognized as the hardest metal carbide known, and is produced by heating the vanadium oxides with carbon to temperatures of over 10000c
Zirconium Carbide Powder
It has an extremely hard refractory material therefore also used in manufacture of tool bits for machine tools cutting heads.