Graphite has excellent physical and chemical properties […]
Graphite has excellent physical and chemical properties, among which the more important is its electrical conductivity. The high-quality electrical conductivity allows natural graphite to be used in many fields of industrial appliances, and there are certain requirements for graphite during use.
1. Graphite is widely used in industrial appliances.
Graphite is widely used as an anode of electrodes, brushes, carbon rods, carbon tubes, and mercury rectifiers in industrial appliances. It can also be used as graphite gaskets, coatings for TV picture tubes, telephone parts, etc. Among them, graphite electrodes are the most widely used. When smelting various iron alloys and alloy steels, graphite electrodes are used. A strong current can be introduced into the smelting area of the electric furnace through the electrode to generate an electric arc. As high as about 2000 degrees, so as to achieve the purpose of smelting or reaction. In addition, when electrolyzing magnesium, aluminum, and sodium, graphite electrodes can also be used for the anode of the electrolytic cell.
2. Industrial electrical appliances have certain requirements for the graphite used.
Graphite has also been fully used in industrial appliances, but all aspects of graphite used in industrial appliances are very demanding. For example, alkaline storage batteries and some special electric carbon products require that the particle size of graphite be controlled from 150 mesh to 325 mesh, that is, within the range of 0.1mm to 0.042mm, and the purity should be above 90% to 99%. Among them, harmful impurities are mainly The metal iron content is required to be below 10%, and the graphite particle size for TV picture tubes is required to be below 0.5um.
Graphite is now widely added to brush materials to improve the electrical conductivity and wear resistance of the brush. Brush materials are mainly used for various engines, converters and motors. There are two main types of brushes, one is resin or coal tar pitch as a binder, and graphite powder and metal powder are used as materials to make graphite brushes, also known as colored brushes; the other is carbon Materials (such as graphite powder, coke powder, etc.) are made of main raw materials, also called black brushes.
1. TD32X black aviation brush.
The brush used in the main generator QF-4.8 of the domestic imitation aircraft is the specially developed TD32X black aviation brush. The base material is DZ type brush, which is processed by dipping and core filling. The brush has excellent commutation performance and three-proof capability, with a service life of about 800 h. The service life of the brush is longer than that of the French 9020M black aviation brush.
2. TD27 black aviation brush.
The TD27 black aviation brush is a new type of aviation brush developed through the two-stage method through technical cooperation with Russia and the introduction of advanced process equipment such as vibrating ball mills, lubricating material granulators and double spiral continuous extruders. This brush is characterized by good commutation performance, appropriate peripheral speed (up to 60m/s), large rated current density (up to 30 A/cm2) and low wear. The flying height of the aircraft using this brush is more than 20,000 meters, the operating temperature can be greater than 200 ℃, and it has excellent three-proof capability. The main technical performance level of this product can be equivalent to that of Russian products, which shows that the production and preparation technology of my country's black aviation brush has reached a new level.
3. T2J5 colored aviation brushes.
The T2J5 colored aviation brushes suitable for large-capacity aviation starter generators are also specially developed. The brush has good commutation performance, low friction loss, and extended service life of the motor, which is 1.5 times that of the original TJ5 brush. And the technical performance of the brush is much higher than the TJ5 brush, reaching the leading level.