Diamond powder is mainly divided into three types: single crystal diamond powder, polycrystalline diamond powder and nano diamond powder.
Single crystal diamond powder is produced from synthetic diamond single crystal abrasive grains, which are crushed and shaped, and produced by a special process.
Polycrystalline diamond powder is made of graphite using a unique directional blasting method. The shock wave of the directional blasting of a high-explosive explosive accelerates the flight of the metal flying piece and hits the graphite piece to cause the graphite to be converted into polycrystalline diamond. Its structure is very similar to that of natural carbonado diamond. Its particles are composed of tiny diamond grains combined through unsaturated bonds. It has good toughness. However, due to the limitation of synthesis conditions of polycrystalline diamond powder, the manufacturer is very Less, the product cost is higher.
Diamond powder has high hardness and good wear resistance, and can be widely used in cutting, grinding, drilling, etc. It is an ideal raw material for grinding and polishing hard alloys, ceramics, gems, optical glass and other high-hardness materials. Diamond powder products are tools and components made by processing diamond powder.
Diamond powder belongs to micron, sub-micron and nano-powder in terms of its particle size. Compared with coarse-grained powder, its specific surface area and specific surface functional groups are significantly increased, so in the production process, the force between the particles is greatly increased. In addition, with the refinement of the particle size, the defects of the particles themselves are reduced, and the strength is bound to increase. It can be seen that the production process of diamond micropowder is quite difficult. It is not only a process of particle refinement, but also changes in crystal structure and surface physical and chemical properties. Therefore, the production process of diamond micropowder is a multi-disciplinary engineering technology issue involving machinery, powder engineering, mechanics, physical chemistry, modern instrumentation and testing technology.
Diamond powder application
Traditional diamond powder can be divided into two categories, polycrystalline diamond powder and single crystal diamond powder. With the rapid development of nanotechnology, a new type has been independently developed among the original two major diamond-like powders: nano-diamond powder.
1.Polycrystalline diamond powder
Polycrystalline diamond is synthesized under the action of a transient strong shock wave formed by an explosion. It is a micron and sub-micron polycrystalline composed of nanocrystals. Polycrystalline is isotropic, has no cleavage surface, impact resistance and high bending strength, so it not only has the hardness of superhard materials, but also has nano The material has exceptionally high strength and high toughness. Its dual advantages constitute its unique physical properties, and it has important applications in high-tech industries and traditional pillar industries.
Uses: Mainly used in the fields of chip optical crystal ultra-fine processing, super-finishing polishing of large silicon wafers, surface modification, etc. The spherical polycrystalline diamond powder has a gray-black appearance with a slight metallic luster.
2.Single crystal diamond powder
The crystal shape of single crystal diamond powder is regular and complete hexa-octahedron, with high strength, toughness and good thermal stability, and strong impact resistance. Uses: Suitable for the manufacture of electroplated products, grinding wheels, grinding wheels, for polishing, carving, automotive glass, high-end furniture, ceramics, hard alloys, magnetic materials, etc.
3. Nano diamond powder
Nano-diamond powder not only has the inherent characteristics of diamond, but also has small size effect, large specific surface area effect, quantum size effect, etc., thus exhibiting the characteristics of nanomaterials. The diamond synthesized in the detonation wave has a cubic structure with a lattice constant of (0.3562+0.0003) nm, a crystal density of 3.1g/cm3, and a specific surface area of 300m2/g～390m2/g. After different chemical treatments, a variety of different functional groups can be formed on the diamond surface. This diamond crystal has a high adsorption capacity.
Other uses of nano-diamond:
(1) Preparing advanced grinding paste and polishing liquid for ultra-fine processing of quartz, optical glass, semiconductor, alloy and metal surfaces.
(2) Preparation of catalyst: Nano-diamond and amorphous carbon have a large specific surface area, contain a variety of surface functional groups, and are very active. The preparation of catalysts can improve the activity data and promote the interaction of organic compounds.
(3) Preparation of nano-composite structural materials: composite nano-diamonds with nano-silicon powder, nano-ceramics and various nano-metals can produce new-type nano-structure materials. Because of their unique properties, they can be used to manufacture semiconductor devices and integrated circuit components. And microcomputer parts.
With the growing maturity of the diamond tool manufacturing industry and the rapid growth of China’s economy, my country’s market demand for diamond powder is also growing rapidly. The advancement of tool manufacturing technology also puts forward higher requirements on the upstream diamond powder industry. Since diamond powders of different crystalline states and different particle types have their own characteristics, a few domestic manufacturers have been able to produce different types of diamond powders according to different uses of diamond powders.
For example: cutting tools (PCD), resin bond abrasive tools, metal bond products, special diamond powder for grinding paste, etc. This is an important step for my country’s diamond micropowder industry to upgrade and adjust its product structure, develop towards high-end specialization, and catch up with the world’s advanced level.