The particle size (i.e., particle size) of 10μm) have good fluidity and are suitable for dry pressing, but higher temperatures or longer times are required during sintering to promote densification. Sintering stage: Fine particles of tungsten carbide have high surface energy and fast atomic diffusion rate during sintering, so they can achieve densification at lower temperatures (such as the sintering temperature of nano tungsten carbide is 100-200℃ lower than that of micron-sized particles), reducing the risk of grain growth. Coarse-grained tungsten carbide requires a higher sintering temperature (usually 1400-1600℃), but it is easy to cause grain coarsening, and it is necessary to control grain growth by adding inhibitors (such as VC, Cr3C2). Dispersion and uniformity Fine particles are easy to agglomerate, and they need to be forced to depolymerize through processes such as high-energy ball milling and ultrasonic dispersion to ensure uniform distribution in the matrix (such as cobalt and nickel) to avoid "cobalt pools" or uneven performance of cemented carbide. Coarse particles are relatively easy to disperse, but attention should be paid to the particle size distribution range (such as D50=5μm and narrow distribution) to avoid large particles from accumulating and causing increased porosity. 3. Key technologies for particle size control Preparation method Vapor deposition method (CVD): Nano-scale tungsten carbide powder can be prepared with uniform particle size but high cost, suitable for high-end applications. Mechanical alloying method: The particle size can be reduced to submicron level by crushing tungsten-carbon composite powder through high-energy ball milling, but impurities need to be prevented from being introduced. Spray drying - carbonization method: a common industrial method that controls the spray droplet size and carbonization temperature to achieve micron-level particle size control (such as D50 = 2-5μm). Detection and characterization Laser particle size analyzer (measuring range 0.01-2000μm) is used to quickly obtain particle size distribution (D10, D50, D90). Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) are used to observe particle morphology (spherical, polyhedral, agglomerated state) and grain boundary structure.">tungsten carbide powder is one of the key factors affecting its performance, processing technology, and application scenarios. Tungsten carbide powders of different particle sizes show significant differences in physical properties, preparation processes, and practical applications. The following analyzes the influence of particle size from multiple dimensions:
I. Influence on physical properties
Hardness and wear resistance
Law: Generally, the smaller the particle size (nanoscale/submicron), the higher the hardness and wear resistance.
Principle: Fine-grained tungsten carbide has a smaller grain size and a higher grain boundary density, which can effectively hinder dislocation movement and crack propagation (fine grain strengthening effect). For example, the Vickers hardness of nano-tungsten carbide can reach more than 2000HV, which is higher than that of ordinary micron-grade tungsten carbide (about 1800HV), and is more suitable for extreme wear environments (such as aerospace seals).
Exception: If the particle size is too fine (such as <100nm), the particles are easy to agglomerate to form "soft agglomerates", which may reduce density and performance.
Specific surface area and activity
Law: The smaller the particle size, the larger the specific surface area, and the higher the chemical activity.
Application:
Nano tungsten carbide powder has more advantages in the fields of catalyst carriers, wear-resistant coatings, etc. (high activity promotes interface bonding).
Micron-sized tungsten carbide powder (such as 1-5μm) has a moderate specific surface area, which makes it easier to control the reaction rate in cemented carbide sintering and avoid excessive oxidation.
2. Impact on the preparation process
Molding and sintering performance
Pressing stage:
Fine particles (such as < 1μm) have poor fluidity and need to be combined with binders (such as paraffin, rubber) or spray granulation technology to improve the moldability.
Coarse particles (such as > 10μm) have good fluidity and are suitable for dry pressing, but higher temperatures or longer times are required during sintering to promote densification.
Sintering stage:
Fine particles of tungsten carbide have high surface energy and fast atomic diffusion rate during sintering, so they can achieve densification at lower temperatures (such as the sintering temperature of nano tungsten carbide is 100-200℃ lower than that of micron-sized particles), reducing the risk of grain growth.
Coarse-grained tungsten carbide requires a higher sintering temperature (usually 1400-1600℃), but it is easy to cause grain coarsening, and it is necessary to control grain growth by adding inhibitors (such as VC, Cr3C2).
Dispersion and uniformity
Fine particles are easy to agglomerate, and they need to be forced to depolymerize through processes such as high-energy ball milling and ultrasonic dispersion to ensure uniform distribution in the matrix (such as cobalt and nickel) to avoid "cobalt pools" or uneven performance of cemented carbide.
Coarse particles are relatively easy to disperse, but attention should be paid to the particle size distribution range (such as D50=5μm and narrow distribution) to avoid large particles from accumulating and causing increased porosity.
3. Key technologies for particle size control
Preparation method
Vapor deposition method (CVD): Nano-scale t 10μm) have good fluidity and are suitable for dry pressing, but higher temperatures or longer times are required during sintering to promote densification. Sintering stage: Fine particles of tungsten carbide have high surface energy and fast atomic diffusion rate during sintering, so they can achieve densification at lower temperatures (such as the sintering temperature of nano tungsten carbide is 100-200℃ lower than that of micron-sized particles), reducing the risk of grain growth. Coarse-grained tungsten carbide requires a higher sintering temperature (usually 1400-1600℃), but it is easy to cause grain coarsening, and it is necessary to control grain growth by adding inhibitors (such as VC, Cr3C2). Dispersion and uniformity Fine particles are easy to agglomerate, and they need to be forced to depolymerize through processes such as high-energy ball milling and ultrasonic dispersion to ensure uniform distribution in the matrix (such as cobalt and nickel) to avoid "cobalt pools" or uneven performance of cemented carbide. Coarse particles are relatively easy to disperse, but attention should be paid to the particle size distribution range (such as D50=5μm and narrow distribution) to avoid large particles from accumulating and causing increased porosity. 3. Key technologies for particle size control Preparation method Vapor deposition method (CVD): Nano-scale tungsten carbide powder can be prepared with uniform particle size but high cost, suitable for high-end applications. Mechanical alloying method: The particle size can be reduced to submicron level by crushing tungsten-carbon composite powder through high-energy ball milling, but impurities need to be prevented from being introduced. Spray drying - carbonization method: a common industrial method that controls the spray droplet size and carbonization temperature to achieve micron-level particle size control (such as D50 = 2-5μm). Detection and characterization Laser particle size analyzer (measuring range 0.01-2000μm) is used to quickly obtain particle size distribution (D10, D50, D90). Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) are used to observe particle morphology (spherical, polyhedral, agglomerated state) and grain boundary structure.">ungsten carbide powder can be prepared with uniform particle size but high cost, suitable for high-end applications.
Mechanical alloying method: The particle size can be reduced to submicron level by crushing tungsten-carbon composite powder through high-energy ball milling, but impurities need to be prevented from being introduced.
Spray drying - carbonization method: a common industrial method that controls the spray droplet size and carbonization temperature to achieve micron-level particle size control (such as D50 = 2-5μm).
Detection and characterization
Laser particle size analyzer (measuring range 0.01-2000μm) is used to quickly obtain particle size distribution (D10, D50, D90).
Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) are used to observe particle morphology (spherical, polyhedral, agglomerated state) and grain boundary structure.
cast@ebcastings.com
WhatsApp：0086 18800596372
The particle size (i.e., particle size) of 10μm) have good fluidity and are suitable for dry pressing, but higher temperatures or longer times are required during sintering to promote densification. Sintering stage: Fine particles of tungsten carbide have high surface energy and fast atomic diffusion rate during sintering, so they can achieve densification at lower temperatures (such as the sintering temperature of nano tungsten carbide is 100-200℃ lower than that of micron-sized particles), reducing the risk of grain growth. Coarse-grained tungsten carbide requires a higher sintering temperature (usually 1400-1600℃), but it is easy to cause grain coarsening, and it is necessary to control grain growth by adding inhibitors (such as VC, Cr3C2). Dispersion and uniformity Fine particles are easy to agglomerate, and they need to be forced to depolymerize through processes such as high-energy ball milling and ultrasonic dispersion to ensure uniform distribution in the matrix (such as cobalt and nickel) to avoid "cobalt pools" or uneven performance of cemented carbide. Coarse particles are relatively easy to disperse, but attention should be paid to the particle size distribution range (such as D50=5μm and narrow distribution) to avoid large particles from accumulating and causing increased porosity. 3. Key technologies for particle size control Preparation method Vapor deposition method (CVD): Nano-scale tungsten carbide powder can be prepared with uniform particle size but high cost, suitable for high-end applications. Mechanical alloying method: The particle size can be reduced to submicron level by crushing tungsten-carbon composite powder through high-energy ball milling, but impurities need to be prevented from being introduced. Spray drying - carbonization method: a common industrial method that controls the spray droplet size and carbonization temperature to achieve micron-level particle size control (such as D50 = 2-5μm). Detection and characterization Laser particle size analyzer (measuring range 0.01-2000μm) is used to quickly obtain particle size distribution (D10, D50, D90). Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) are used to observe particle morphology (spherical, polyhedral, agglomerated state) and grain boundary structure.">tungsten carbide powder is one of the key factors affecting its performance, processing technology, and application scenarios. Tungsten carbide powders of different particle sizes show significant differences in physical properties, preparation processes, and practical applications. The following analyzes the influence of particle size from multiple dimensions:
I. Influence on physical properties
Hardness and wear resistance
Law: Generally, the smaller the particle size (nanoscale/submicron), the higher the hardness and wear resistance.
Principle: Fine-grained tungsten carbide has a smaller grain size and a higher grain boundary density, which can effectively hinder dislocation movement and crack propagation (fine grain strengthening effect). For example, the Vickers hardness of nano-tungsten carbide can reach more than 2000HV, which is higher than that of ordinary micron-grade tungsten carbide (about 1800HV), and is more suitable for extreme wear environments (such as aerospace seals).
Exception: If the particle size is too fine (such as <100nm), the particles are easy to agglomerate to form "soft agglomerates", which may reduce density and performance.
Specific surface area and activity
Law: The smaller the particle size, the larger the specific surface area, and the higher the chemical activity.
Application:
Nano tungsten carbide powder has more advantages in the fields of catalyst carriers, wear-resistant coatings, etc. (high activity promotes interface bonding).
Micron-sized tungsten carbide powder (such as 1-5μm) has a moderate specific surface area, which makes it easier to control the reaction rate in cemented carbide sintering and avoid excessive oxidation.
2. Impact on the preparation process
Molding and sintering performance
Pressing stage:
Fine particles (such as < 1μm) have poor fluidity and need to be combined with binders (such as paraffin, rubber) or spray granulation technology to improve the moldability.
Coarse particles (such as > 10μm) have good fluidity and are suitable for dry pressing, but higher temperatures or longer times are required during sintering to promote densification.
Sintering stage:
Fine particles of tungsten carbide have high surface energy and fast atomic diffusion rate during sintering, so they can achieve densification at lower temperatures (such as the sintering temperature of nano tungsten carbide is 100-200℃ lower than that of micron-sized particles), reducing the risk of grain growth.
Coarse-grained tungsten carbide requires a higher sintering temperature (usually 1400-1600℃), but it is easy to cause grain coarsening, and it is necessary to control grain growth by adding inhibitors (such as VC, Cr3C2).
Dispersion and uniformity
Fine particles are easy to agglomerate, and they need to be forced to depolymerize through processes such as high-energy ball milling and ultrasonic dispersion to ensure uniform distribution in the matrix (such as cobalt and nickel) to avoid "cobalt pools" or uneven performance of cemented carbide.
Coarse particles are relatively easy to disperse, but attention should be paid to the particle size distribution range (such as D50=5μm and narrow distribution) to avoid large particles from accumulating and causing increased porosity.
3. Key technologies for particle size control
Preparation method
Vapor deposition method (CVD): Nano-scale t 10μm) have good fluidity and are suitable for dry pressing, but higher temperatures or longer times are required during sintering to promote densification. Sintering stage: Fine particles of tungsten carbide have high surface energy and fast atomic diffusion rate during sintering, so they can achieve densification at lower temperatures (such as the sintering temperature of nano tungsten carbide is 100-200℃ lower than that of micron-sized particles), reducing the risk of grain growth. Coarse-grained tungsten carbide requires a higher sintering temperature (usually 1400-1600℃), but it is easy to cause grain coarsening, and it is necessary to control grain growth by adding inhibitors (such as VC, Cr3C2). Dispersion and uniformity Fine particles are easy to agglomerate, and they need to be forced to depolymerize through processes such as high-energy ball milling and ultrasonic dispersion to ensure uniform distribution in the matrix (such as cobalt and nickel) to avoid "cobalt pools" or uneven performance of cemented carbide. Coarse particles are relatively easy to disperse, but attention should be paid to the particle size distribution range (such as D50=5μm and narrow distribution) to avoid large particles from accumulating and causing increased porosity. 3. Key technologies for particle size control Preparation method Vapor deposition method (CVD): Nano-scale tungsten carbide powder can be prepared with uniform particle size but high cost, suitable for high-end applications. Mechanical alloying method: The particle size can be reduced to submicron level by crushing tungsten-carbon composite powder through high-energy ball milling, but impurities need to be prevented from being introduced. Spray drying - carbonization method: a common industrial method that controls the spray droplet size and carbonization temperature to achieve micron-level particle size control (such as D50 = 2-5μm). Detection and characterization Laser particle size analyzer (measuring range 0.01-2000μm) is used to quickly obtain particle size distribution (D10, D50, D90). Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) are used to observe particle morphology (spherical, polyhedral, agglomerated state) and grain boundary structure.">ungsten carbide powder can be prepared with uniform particle size but high cost, suitable for high-end applications.
Mechanical alloying method: The particle size can be reduced to submicron level by crushing tungsten-carbon composite powder through high-energy ball milling, but impurities need to be prevented from being introduced.
Spray drying - carbonization method: a common industrial method that controls the spray droplet size and carbonization temperature to achieve micron-level particle size control (such as D50 = 2-5μm).
Detection and characterization
Laser particle size analyzer (measuring range 0.01-2000μm) is used to quickly obtain particle size distribution (D10, D50, D90).
Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) are used to observe particle morphology (spherical, polyhedral, agglomerated state) and grain boundary structure.
cast@ebcastings.com
WhatsApp：0086 18800596372
