Facts about 石墨: Applications & 使用
石墨 is a naturally-occurring form of crystalline carbon. It is a native element mineral found in metamophic and igneous rocks. 石墨 is a mineral of extremes. It is extremely soft, cleaves with very light pressure, and has a very low specific gravity. In contrast, it is extremely resistant to heat and nearly inert in 联系 with almost any other material. These extreme properties give it a wide range of uses in metallurgy and manufacturing.
Applications & Common 使用 of 石墨
Carbon Brushes (electrical conductivity and low friction and self-lubrication).
- Carbon brushes for electrical motors are manufactured from high purity synthetic graphite.
- Copper-graphite and silver-graphite impregnated composites are used in applications where high electrical conductivity is required: railway technology, wind turbine generators, tacho generators.
Refractories (thermal resistance, thermal conductivity and low wettability by liquid metals).
- Magnesia-carbon bricks for lining steel making furnaces contain up to 25% of graphite.
- Alumina-carbon composites are used in ladles for liquid steel, pouring nozzles, sliding gates.
- Clay-graphite and silicone carbide-graphite composites containing natural coarse flake graphite are used for manufacturing thermocouple and heater tubes, foundrty tools and crucibles for melting non-ferrous metals.
- Facing sand in Sand Casting contains flake graphite to prevent sticking of sand particles to the casting surface.
Electrodes for electric arc furnaces (thermal resistance and electric conductivity).
Molds for continuous casting from isostatically pressed graphite(thermal conductivity, thermal resistance, low friction and self-lubrication, low wettability).
Lubricants (低 friction and self-lubrication).
- 石墨 powder as a solid lubricant.
- 石墨 powder added to oils and greases.
- Polymer coatings containing graphite powder.
- Bronze-graphite composites for sliding bearings.
Friction materials (低 friction, self-lubrication, thermal conductivity, thermal resistance) contain up to 15% graphite powder for controlling coefficient of friction and dissipation of friction energy.
- 离合器.
- Brake drums and pads.
石墨 Foil (thermal resistance, chemical resistance) is made of a graphite powder treated by sulfuric acid and rolled to a required thickness. 石墨 foil is used for manufacturing high temperature gaskets and packages.
Cathodic material in zinc-carbon and lithium-ion batteries (electrical conductivity and chemical resistance) contain fine high purity graphite powder.
Moderators in nuclear reactors (resistance to neutron radiation, thermal resistance).
Carbon fibers for Carbon Fiber Reinforced Polymer Composites (high strength, low density). Automotive, marine and aerospace parts, sport goods (golf clubs, 滑雪板, tennis racquets, fishing rods), bicycle frames are made of Carbon Fiber Reinforced Polymer Composites.
Carbon-Carbon Composites (低 CTE, high Modulus of Elasticity and strength, low density). High performance braking systems, refractory components, hot-pressed dies, heating elements, turbojet engine components.
铅笔 (低 friction) consist of a mixture of microcrystalline graphite and clay.
Physical Properties of 石墨
Chemical Classification – Native element
Color – Steel gray to black
条纹 – 黑色的
光泽 – Metallic, sometimes submetallic or earthy
Diaphaneity – 不透明的
分裂。 – Perfect in one direction
Mohs Hardness – 1 to 2
Specific Gravity – 2.1 to 2.3
Diagnostic Properties – Color, streak, slippery feel, specific gravity
Chemical Composition – C
Crystal System – Hexagonal
使用 of 石墨
- Used to manufacture heat and chemical resistant containers and other objects.
- Battery anodes.
- A dry lubricant.
- The “lead” in pencils.
石墨 Key Properties
- Bulk Density (g/cm3) – 1.3-1.95
- Porosity (%) – 0.7-53
- Modulus of Elasticity (GPa) – 8-15
- Compressive strength (MPa) – 20-200
- Flexural strength (MPa) – 6.9-100
- Coefficient of Thermal Expansion (x10-6 °C) – 1.2-8.2
- Thermal conductivity (W/m.K) – 25-470
- Specific heat capacity (J/kg.K) – 710-830
- Electrical resistivity (Ω.m) – 5×10-6-30×10-6
石墨 Specifications
Mesh Size -200 Mesh
Quantity – 28g
Odor – Odorless
UN Number – UN1325
Solubility Information – Insoluble in water.
Physical Form – Powder, Ultra Superior purity
Percent Purity – 99.9999%
Grade – Ultra superior purity
Chemical Name or Material – 石墨 powder, Natural
Assay – (metals basis)
If you’re interested in discussing how 石墨 can be used for your application, please feel free to 联系 our technical team directly.