Machined Graphite

About Machined Graphite and Machined Graphite Suppliers Including: Carbon Graphite, Graphite Design, Graphite Machining, Graphite Rods & Graphite Tubes.

Machined graphite is formed for use in a wide variety of manufactured parts benefiting the automotive, aerospace, semiconductor, chemical, metallurgical, nuclear and electronics industries. It is usually the result of a copper and pure graphite composite, creating a material that is both structurally sound and reliable. Copper graphite is expensive, but it has improved conductivity and strength compared to pure graphite. Other metallic graphite mixtures may be used but may prove less effective.

In order to understand the formation of machined graphite, it is important to know that pure graphite is of two different types, natural and synthetic. Natural graphite is one of four forms of carbon, and manufacturers use it to produce machined graphite. It is combined with tar pitch and petroleum coke during heat treatments to make synthetic graphite, which is the type that is actually used in machined graphite parts. The heat enables the machined graphite to increase its strength, making it one of the easiest electrode materials, and providing exceptional shock resistance as well. As an electrode, machined graphite is used in EDM to create parts. Because the strength of graphite increases as the temperature rises, it is preferable to most metals in particular applications. Aside from its strength, graphite’s conductivity, flexibility and chemical resistance add to its favorability.

Machined graphite can refer to one of three different processes, including extruded, compression molded and isostatically pressed. These processes each create unique grades of graphite that are particularly suited for certain parts and components. Extruded and isostatically pressed graphite, distributed in either round or rectangular blocks, are used mainly in manufacturing parts, such as rods, tubes and fixtures. Compression molded graphite is of high demand in the sporting goods industry and is used primarily in the production of golf clubs and fishing poles. Graphite in a variety of forms also serves as a pigment, UV shield, lubricant or conductor of electricity in numerous products.

The manufacturers of machined graphite have a wide range of capabilities and work with customers to handle their machined graphite needs. Manufacturers offer custom manufacturing and are capable of aiding in the design of the part as well. Graphite if produced in bulk quantities for future shaping, or as specific components and already finished parts, whichever suits the customer’s needs. Manufacturers also can assist in the recycling of obsolete graphite scrap, parts or particles. Due to heightened environmental restrictions and regulation, it is best to utilize the aid of a graphite manufacturer in any recycling choices. Another safety issue occurs when graphite dust is present in the work place. It is considerably hazardous if it combines with machine oil; this mixture can destroy the accuracy of machines.

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Images Provied by Becker Brothers Graphite Corporation

Types of Machined Graphite

• Carbon graphite is used in mechanical applications due to its strength and hardness. Carbon graphite has a lower level of heat resistance and conductivity than graphite.
  
• Extruded graphite has relatively fine grain size, and has good mechanical, electrical and thermal properties, with a preferential grain orientation and low ash content. Density, mechanical strength and oxidation resistance can be improved by means of further impregnation.
  
• EDM graphite is an important component of electrical discharge machines. The use of graphite causes less wear and tear on the EDM electrodes and removes metal quickly and efficiently.
  
• Graphite bearings are often used in load capacity systems along with graphite bushings.
  
• Graphite composites are beneficial because they are lightweight, yet strong and durable. Graphite composites are used in the automotive, airplane, and aerospace industries to provide structural support and reinforcement.
  
• Graphite crucibles are used to store materials and samples during fusion and other mixing processes.
  
• Graphite design produces many products from machined graphite.
  
• Graphite electrodes are used in ladle furnaces and electric arc furnaces. Graphite electrodes are advantageous for their high conductivity and performance under high temperatures.
  
• Graphite fixtures consist of packaging fixtures and sealing fixtures. Graphite fixtures are used in the automation and semiconductor industries.
  
• Graphite machining is the process that produces parts out of synthetic graphite materials.
  
• Graphite rods are used in the fiber optics and semiconductor industries to produce a wide variety of machine components, including dies, spindles, and chucks.
  
• Graphite tubes are used in furnaces because of graphite’s low heat sensitivity. Graphite is also used in the production of fluxing tubes used in the metal manufacturing industry; other industries using graphite tubes include chemical and scientific industries.
  
• Isostatically pressed graphite is an especially fine grain, dense, isotropic graphite, which can be produced in large dimensions.

Machined Graphite Terms

Angstrofine – The most advanced type of EDM graphite. Angrostofine is used when fine detail and a smooth finish is required.

Billet – An uncut block of graphite produced by the manufacturer that ranges from two to seven square inches. A billet is commonly used for longer projects.

Breakthrough – The exit end of a through-hole cavity which occurs at the moment of completion.

Carbon – An abundant element of natural occurrence, often used instead of the word graphite. Graphite is a type of the element carbon.

Coke – A processed form of coal. Processed coke burns more steadily and is stronger than metallurgical coke.

Composite – Two or more materials combined. An example is copper graphite, which is a metallic/carbon composite.

EDM – Electrical Discharge Machining; a process in which metal is removed through burning or erosion instead of through cutting.

Electrode – A tool used in EDM which mirrors the desired shape. The electrode must be made out of materials that can carry an electric current.

Filler – The carbonaceous particles in manufactured graphite comprising the base aggregate in an unbaked green-mix formula.

Flash – Thin fin or web of metal extending beyond the confines of the casting, usually along the joint line as a result of poor contact between cope and drag molds.

Grain – Referring to a region in a carbon or graphite body that is identifiable as being derived from a particle of filler.

Horn Gate – Curved gate in the shape of a horn arranged to allow entry of molten metal at the bottom of the casting cavity.

Isotropic – Having uniform properties in all directions. The measured properties of an isotropic material are independent of the axis of testing.

Machined – To shape, cut or finish a product by the use of a machine.

Premium Graphite – A material with a particle size of five microns or less.

Transducer – Changes one form of energy into another; in EDM it is used to change electromagnetic force into mechanical force for the machining of graphite. Although there is sound produced when machining graphite, it is too high pitched for most human hearing.

Trim Die – Die used for shearing or trimming a workpiece.

Workpiece – Material that is being machined. The material will continue to be operated on until it is a replica of the original.