Diamond, commonly known as “diamond drill,” is a mineral composed of carbon atoms. It is an allotrope of graphite, with the chemical formula C, and is the natural form of what we typically recognize as a diamond. Diamond is the hardest naturally occurring substance on Earth.
Diamond micro powder is mainly divided into three types: single-crystal diamond micro powder, polycrystalline diamond micro powder, and nanodiamond micro powder. Additionally, there are other types, such as pseudo-polycrystalline diamond micro powder and agglomerated diamond micropowder. It has has high hardness and wear resistance.
This makes it ideal for cutting, grinding, drilling, and polishing. It is especially suited for hard materials like cemented carbide, ceramics, gemstones, and optical glass.
Diamond micro powder, in terms of particle size, falls within the micrometer, sub-micrometer, and nanometer ranges. Compared to coarse powders, its specific surface area and surface functional groups are significantly increased, enhancing the interactions between particles during the production process.
Additionally, as the particle size decreases, defects in the particles reduce, leading to increased strength. The production of diamond micropowder is a complex process. It involves not just particle size reduction, but also changes in crystal structure and surface physicochemical properties. The production technology of diamond micro powder is a multidisciplinary engineering challenge. It involves mechanics, powder engineering, physical chemistry, modern instrumentation, and testing techniques.
Diamond Micro Powder Production Process and Equipment
Currently, the most common diamond micro powder is produced by crushing, purifying, and classifying synthetic diamonds. Generally, there are two basic methods for crushing moderately coarse materials to micron or sub-micron size: mechanical impact and air stream grinding.
A ball mill is a crushing device that primarily uses mechanical compression, with some low-speed impact action. In terms of methods, using a ball mill to crush diamonds for diamond micropowder production is the most commonly used approach.
However, due to its low production efficiency, it has now been replaced by an air jet mill.
The working principle of the air jet mill is that compressed air acts as the working medium.
Compressed air is injected at high speed into the grinding chamber through a special supersonic nozzle. The air stream carries the material at high speed, causing intense collisions, friction, and shear between particles, thereby achieving crushing.
This crushing method is beneficial for diamond micro powder production as it produces ideal particle shapes. The biggest advantage of the air stream grinder is that it is not limited by mechanical line speed. It can generate very high air speeds, especially supersonic grinders, which achieve speeds several times the speed of sound. This results in huge kinetic energy, making it easier to obtain micron and sub-micron ultrafine powders. From a crushing principle perspective, this machine type has promising potential for diamond micropowder production.
Diamond powder types and applications
Single-crystal diamond micro powder
ingle-crystal diamond micropowder is made from synthetic diamond single crystal abrasives. It is processed through crushing and shaping using special techniques for superhard materials. Its particles retain the single-crystal characteristics of diamond. The particles have a regular and complete hexagonal-octahedral crystal shape. It has high strength and toughness. It also has excellent thermal stability and strong impact resistance.
Application：It is suitable for the manufacturing of electroplated products, grinding wheels, and polishing wheels. It is used for polishing and engraving high-end stone, automotive glass, high-quality furniture, ceramics, cemented carbide, and magnetic materials. It is also an ideal raw material for grinding and polishing hard materials like cemented carbide, ceramics, gemstones, and optical glass.
Polycrystalline diamond micro powder
Polycrystalline diamond micropowder is produced by high energy during an explosion, which converts graphite into diamond with a carbonado-like structure. Due to the short synthesis time, diamond grains have structural defects and consist mainly of microcrystals smaller than 100 nanometers.
In some special material processing, polycrystalline diamond will not cause deep scratches on the workpiece. Under pressure, microcrystals on the diamond surface continuously shed, forming new cutting edges. This characteristic enables the rapid grinding and polishing of high-hardness special materials. Polycrystalline diamond has a removal rate 2-4 times higher than regular diamond products, without causing scratches.
Application：It is mainly used in fields such as chip optical crystals, ultra-fine processing, large silicon wafer polishing, and surface modification. Spherical polycrystalline diamond micropowder has a gray-black appearance with a slight metallic luster.
Pseudo-polycrystalline diamond micro powder
Pseudo-polycrystalline diamond micropowder has a porous structure, with a surface full of sharp cutting edges. After grinding and polishing, the surface Ra value significantly decreases.
Application: It is widely used in precision grinding and polishing of hard and brittle materials such as sapphire, silicon carbide crystals, and ceramics.
Nanodiamond micro powder
Nanodiamond micro powder consists of microcrystalline diamond particles with a size smaller than 20 nanometers. Special detonation synthesis conditions make its particles nearly spherical, with a surface rich in functional groups. Its specific surface area is an order of magnitude higher than that of single-crystal diamonds. It not only has the excellent hardness and grinding properties of diamond, but also possesses new characteristics of nanomaterials, making it applicable in a wider range of fields.
The development trends of diamond micro powder
Currently, the production technology and process level of the diamond micropowder industry are improving. The production process is gradually becoming automated. With the development of advanced technology and high-end manufacturing, there are increasing demands for diamond micropowder performance. In the future, the diamond micro powder industry will develop towards finer, specialized, and functionalized directions.
Epic powder
Epic Powder, 20+ years of work experience in the ultrafine powder industry. Actively promote the future development of ultra-fine powder, focusing on crushing,grinding,classifying and modification process of ultra-fine powder. Contact us for a free consultation and customized solutions! Our expert team is dedicated to providing high-quality products and services to maximize the value of your powder processing. Epic Powder—Your Trusted Powder Processing Expert !