A brief discussion on the technology of high grade diamond powder

The technical indicators of high-quality diamond micro powder involve particle size distribution, particle shape, purity, physical properties and other dimensions, which directly affect its application effect in different industrial scenarios (such as polishing, grinding, cutting, etc.). The following are the key technical indicators and requirements sorted out from the comprehensive search results:

Particle size distribution and characterization parameters
1. Particle size range
The particle size of diamond micro powder is usually 0.1-50 microns, and the requirements for particle size vary significantly in different application scenarios
Polishing: Select 0-0.5 micron to 6-12 micron of micro powder to reduce scratches and improve surface finish 5
Grinding: Micro-powder ranging from 5-10 microns to 12-22 microns is more suitable for both efficiency and surface quality.
Fine grinding: 20-30 micron powder can improve the grinding efficiency
2. Particle size distribution characterization
D10: the corresponding particle size of 10% of the cumulative distribution, reflecting the proportion of fine particles. The proportion of fine particles should be controlled to avoid the reduction of grinding efficiency.
D50 (median diameter): represents the average particle size, which is the core parameter of particle size distribution and directly affects the processing efficiency and accuracy.
D95: the corresponding particle size of 95% cumulative distribution, and control the content of coarse particles (such as D95 exceeding the standard is easy to cause scratches on workpieces).
Mv (volume average particle size): greatly affected by large particles and used to evaluate the coarse end distribution
3. Standard system
International standards commonly used include ANSI (e.g. D50, D100) and ISO (e.g. ISO6106:2016).
Second, particle shape and surface characteristics
1. Shape parameters
Roundness: the closer the roundness is to 1, the more spherical the particles are and the better the polishing effect; particles with low roundness (many corners) are more suitable for electroplating wire saws and other scenes that need sharp edges.
Plate-like particles: particles with transmittance> 90% are regarded as plate-like, and the proportion should be less than 10%; excessive plate-like particles will lead to deviation of particle size detection and unstable application effect.
Bead-like particles: the length to width ratio of particles> 3:1 should be strictly controlled, and the proportion should not exceed 3%.
2. Shape detection method
Optical microscope: suitable for shape observation of particles above 2 microns
Scanning electron microscope (SEM): used for the morphology analysis of ultrafine particles at the nanometer level.
Purity and impurity control
1. Impurity content
Diamond purity should be> 99%, and metal impurities (such as iron, copper) and harmful substances (sulfur, chlorine) should be strictly controlled below 1%.
Magnetic impurities should be low to avoid the effect of agglomeration on precision polishing.
2. Magnetic susceptibility
High purity diamond should be close to non-magnetic, and high magnetic susceptibility indicates the residual metal impurities, which need to be detected by electromagnetic induction method.
Physical performance indicators
1. Impact toughness
The crushing resistance of particles is characterized by the unbroken rate (or semi-cracked times) after impact test, which directly affects the durability of grinding tools.
2. Thermal stability
Fine powder needs to maintain stability at high temperature (such as 750-1000℃) to avoid graphite formation or oxidation resulting in strength reduction; commonly used thermogravimetric analysis (TGA) detection.
3. Microhardness
The microhardness of diamond powder is up to 10000 kq/mm2, so it is necessary to ensure high particle strength to maintain cutting efficiency.
Application adaptability requirements 238
1. Balance between particle size distribution and processing effect
Coarse particles (such as high D95) improve grinding efficiency but reduce surface finish: fine particles (smaller D10) have the opposite effect. Adjust the distribution range according to requirements.
2. Shape adaptation
Block multi-edge particles are suitable for resin grinding wheels; spherical particles are suitable for precision polishing.
Testing methods and standards
1. Particle size detection
Laser diffraction: widely used for micron/submicron particles, simple operation and reliable data;
Sieve method: only applicable to particles above 40 microns;
2. Shape detection
Particle image analyzer can quantify the parameters such as sphericity and reduce the error of manual observation;

sum up
High-quality diamond micro-powder requires comprehensive control over particle size distribution (D10/D50/D95), particle shape (roundness, flake or needle content), purity (impurities, magnetic properties), and physical properties (strength, thermal stability). Manufacturers should optimize parameters based on specific application scenarios and ensure consistent quality through methods such as laser diffraction and electron microscopy. When selecting, users should consider specific processing requirements (such as efficiency and finish) and match the indicators accordingly. For example, precision polishing should prioritize controlling D95 and roundness, while rough grinding can relax shape requirements to enhance efficiency.
The above content is excerpted from the superhard materials network.


Post time: Jun-11-2025