Aupac carbon brushes are made using a process known as "powder metallurgical technology." Producing metal products and materials using powder metallurgical technology involves mixing and blending several types of metal powder at a proper ratio, placing it in a mold, compacting and pressing it at high pressures, and then putting it in an oven for sintering at a temperature below the metal-fusion point. The term "powder metallurgical technology" is also often used to describe processes involving ingredients other than metal powder, such as carbon and oxide powder.

About Graphite

Substances composed solely of carbon atoms include diamond, graphite, coke, and the carbon nanotube, which has attracted considerable attention in recent years. These are known as "allotropes" of carbon.
Among these, graphite has the following characteristics:

• High electrical conductivity
• Low coefficient of friction
• High chemical resistance
• High heat resistance

These properties arise from graphite's characteristic crystal structure.
Graphite has a layered crystal structure. Within each layer, carbon atoms are joined by strong covalent bonds. Between the layers, however, the bonding is much weaker, held together only by what is known as "van der Waals force."
As a result, graphite exhibits electrical conductivity comparable to metals within each layer, while the layers themselves slide easily past one another under external force. This is what gives graphite its low-friction properties.
A familiar example is pencil lead. Writing with a pencil is possible because layers of graphite flake off and adhere to the surface of the paper. Because the graphite layers slide so easily, writing does not tear or damage the paper.

Carbon Brushes and Graphite

Carbon brushes require the following properties:

• Low friction against counterpart materials rotating or moving at high speed
• Stable performance in receiving and supplying large electric currents
• Resistance to heat generation
• Resistance to oxidation and chemical corrosion

Graphite meets these demands at a high level, which is why it is widely used as the primary material for carbon brushes.

Artificial Graphite and Natural Graphite

The production of graphite begins with the thermal decomposition of organic matter under airtight conditions, yielding a solid material with a high carbon content. This process is called "carbonization."
This carbon material is then processed at temperatures above 2,500°C, also under airtight conditions, causing its crystal structure to develop into graphite. This process is known as "graphitization."
Graphite produced artificially in this way is called artificial graphite, while graphite formed naturally is called natural graphite.

The Potential of Carbon

Carbon is a special element, playing a vital role not only in graphite and diamond but in all organic matter and life itself.
In recent years, new carbon materials such as carbon nanotubes and graphene have been developed, further expanding carbon's potential. Carbon is truly a material full of possibility, capable of generating a remarkable range of functions.