Carbon Graphite Report
Properties of Carbon Graphite
| Physical Properties Of Graphite | Atomic number is 6. Melting point is 3773.15K. Boiling Point is 5100.5K. Atomic mass is 12.01 amu. Crystal structure is hexagonal and cubic. Color is black or grey. Density is -2.26 g/cm³. Specific gravity is 1.9-2 (Azom, 2001). |
| Mechanical properties of Graphite | Compressive strength is 50.038 ksi. Bulk modulus is 2.21 10^6 psi. Ductility is 0.0018. Elastic limit is 11.02 ksi. Endurance limit is 2.61 ksi. Hardness is 47.2 ksi. Poisson’s ratio is 0.23. Tensile strength is 11.02 ksi. |
| Environmental properties of graphite | Resistance factor of flammability is 3. Fresh water is 5. Organic Solvent is 5. Sea water is 5. Strong acid is 4. UV is 5. Wear is 3 (Properties and characteristics of graphite, 2015). |
| Electrical Properties of graphite | Value of arc resistance for graphite is 8 ohms. Dielectric constant for graphite is 1 MHz at 25 degrees Celsius. Thermal conductivity of graphite is 107-340.0 W/mK. Dielectric strength is 6.35mm. Flexural Strength for graphite is 40-300 MPa. |
| Chemical Properties of Carbon graphite | It has very low toxicity. It shines brightly when exposed to sunlight. It is highly reactive towards acids like HCL and nitric acid. It is used as a catalyst for the alkali reactions. When subjected to petroleum based things it is toxic, as it contains carbon which does not support burning. When placed in saltwater it forms graphene. |
| Thermal properties of graphite | Thermal conductivity of graphite is measured at a temperature range of -191 degrees to 100 degrees. It ranges from 9-12 (W/m.Cͦ). It is increased by increasing temperature. Coefficient of thermal expansion of graphite is 2-6 (10^-6m/(m K))*. Hardness of carbon graphite ranges between 65-85. Modulus of elasticity for graphite lies between 14-17 GNm^-2. Flexural strength of carbon graphite lies between 52-63 MNm^-2. Apparent density of graphite lies between 1.72-1.75 (g.cm^-3). Temperature limit in air for graphite is 315 degrees Celsius. Transition in graphite is so slow that this temperature is not noticeable. |
| Metallurgical properties of graphite | Graphite is a highly malleable material. It consists of hexagonal rings of carbon. Its layers are very weak and they can easily slide over each other. Graphite is machinable but it is very sensitive. Machining of graphite requires precision and accuracy. It needs anodes, boots, crucibles, electrodes, fixtures and heating elements (Kourtides, 1990). |
Material Overview
Sometime before 1565, large deposits of graphite were first discovered in Barrowdale parish, England. Graphite is completely made of carbon. It has a hexagonal structure and its color is grey or dark black. Synthetic graphite was discovered during an accident by Edward Goodrich Acheson when he was trying to make silicon carbide by the reaction of silica and amorphous carbon in an electric furnace. Such types of furnaces are still being used to manufacture synthetic graphite, and that process is also named after Mr. Acheson (Tamashausky, 2006). Natural graphite mostly occurs during metamorphism in metamorphic rocks. During the reign of Elizabeth, graphite was used for lining the molds of cannonballs. Graphite had great military importance at that time. Its movement and usage were strictly observed by only the Crown. Since sixteenth century graphite pencils were used for paper writing. In present era, graphite is being used in the manufacture of battery anodes. These batteries are being used in laptops, mobile, vehicles, etc. The dies which are used for the extrusion of hot steel also use graphite as lubricant. Graphite is successfully being used a replacement for asbestos in making brake shoes of heavy vehicles. Railroad and parts of rail engines which are directly exposed to sunlight are protected from corrosion using the liquid mixture of graphite and waste lubricants. It is also being used in the field of medicine. For example, the valves which are used in the transplant of hearts are being made of graphite these days. Graphite has many advantages which make it unique. It is the only material right now whose mechanical and thermal properties are increased with temperature. It is highly shock absorbent and resistant. It can easily remove hard materials much better than copper. However, Graphite is expensive. Synthetic graphite is mostly inert and does not damage human organs. Graphite is not very harmless. It can cause severe irritation to skin, eyes and nose. It can cause watering of eyes and skin itching.
| Recommended Application of Carbon graphite |
| It is dry lubricant and can be used to replace wet lubricants like oil, etc. |
| It is the only non-metal element which is a good conductor of electricity. It could be used in devices where heat is a big issue, as its thermal properties are enhanced with increased temperature. |
| It could be used for isolation and coating of big ships and planes in order to protect from corrosion and wear and tear as the mechanical properties of graphite are also increased with increase in temperature. |
| Graphite is used as a steel hardener. It could be used in die making processes. The outer and inner layers of the dies are coated with a layer of graphite in order to protect them from excessive wear and tear. It should be used during the manufacturing of the dies. Dies are mostly made of stainless steel and if graphite is added during their formation, it would provide strength and hardness. |
References
Azom. (2001). Carbon-Graphite Materials. AZO Materials, 7.
Kourtides, D. A. (1990). Review of Thermal Properties of graphite composite materials. NASA Technical Memorandum 100049 , 50.
Properties and characteristics of graphite. (2015). POCO GRAPHITE, 42.
Tamashausky, A. V. (2006). An Introduction to Synthetic Graphite., 12.
