Silicon carbide is a hard ceramic material widely used across many modern industrial fields. For example, industrial processing, ceramics manufacturing, and semiconductor manufacturing. Black and green silicon carbide are the two most commonly used. Their difference lies not only in color, but also in composition and applications.
This article will provide the details of black and green silicon carbides. Learning their differences will help you improve your industrial processes and product quality.
Definitions of Black Silicon Carbide and Green Silicon Carbide
Black Silicon Carbide Powder and Green Silicon Carbide PowderBlack Silicon Carbide
Black SiC is commonly made by quartz sand and petroleum coke, smelted at 2,200℃. It offers excellent cost-effectiveness with high hardness and toughness. It is mainly used where high wear and high-temperature durability are needed.
Green Silicon Carbide
Green SiC is made from high-purity quartz sand and petroleum coke smelted under 2,500℃ with purification. Thus, green SiC has high purity and hardness. Green SiC is commonly used in both precision ceramics and high-end abrasives.
The table below shows the main properties of these 2 types of silicon carbide. You can quickly explore their different properties.
| Property | Black Silicon Carbide | Green Silicon Carbide |
| Color | Black or Dark Gray | Green or Light Green |
| Purity | 95%-98% | Not less than 98.5% (up to 99%+) |
| Main Impurities | ·Free carbon ·Iron oxide (≤1.5) | ·Trace free carbon (≤ 0.3) ·Iron oxide (≤0.2) |
| Smelting Temperature | 2,200℃ | 2,500℃ |
| Particle Density | ≥3.12 g/cm3 | ≥3.18 g/cm3 |
| Crystal Characteristics | Hexagonal system (Relatively coarse grains) | Hexagonal system (More complete and pure crystals) |
| Mohs Hardness | 9.2-9.3 | 9.4-9.5 |
| Toughness | Better; not easily fractured | Poorer; higher brittleness |
| Thermal Conductivity (at room temp) | 71-130 W/(m·K) | 100-140 W/(m·K) (Higher purity yields better conductivity) |
| Cost | Lower; high cost-effectiveness | Higher |
Why are They Different in Color?
The color difference is because of the diversity of purity and smelting processes.
Black silicon carbide is colored primarily by the impurities. During the smelting, petroleum coke and anthracite leave behind a little free carbon. Iron oxide impurities also cannot be removed completely. Impurities are uniformly distributed in the crystal gaps to absorb most visible light.
Green silicon carbide is colored by high-purity raw materials and high-temperature smelting. These processes can minimize impurities, and pure hexagonal SiC crystals reflect light in the green wavelength range. Thus, it ultimately shows green.
Applications of Black and Green Silicon Carbide
Different hardness, toughness, and purity make the applications of black and green silicon carbide are also different. You can select the appropriate one based on your production process.
Applications of Black Silicon Carbide
Black silicon carbide possesses excellent hardness and toughness at a relatively low cost. It is mainly used in heavy-duty and coarse processing where precision is not stringently required, and processing efficiency is a priority.
Black silicon carbide will fracture to form sharp cutting edges when it wears down. In the field of abrasives and grinding, it is the preferred choice for coarse grinding, cutting, and rust removal of aluminum, copper alloys, and non-metallic hard and brittle materials. The efficiency is 30% higher than traditional abrasives.
Black silicon carbide also serves as wear-resistant ceramic liners, reducing equipment wear rates by more than 50%. It will significantly lower maintenance downtime, saving you costs.
Moreover, black silicon carbide has a wide range of uses in metallurgy, refractory, and emerging high-tech fields such as internal wall coatings for photovoltaic crucibles and anode coating for lithium batteries.
Wear-Resistant Liners Made by Black Silicon CarbideApplications of Green Silicon Carbide
Green silicon carbide features higher purity and hardness, but is more brittle. Green silicon carbide is mainly used in precision processing where high accuracy and purity are required. It is especially suitable for high-end industries like semiconductor manufacturing.
Green silicon carbide abrasive grains are sharp and uniform in size. For the precision grinding and polishing of materials like optical glass and precision ceramics, it is the preferred choice. Green SiC abrasive enables nano-scale polishing effects. It can be used for precision industrial processing, such as optical glass grinding, to prevent scratches and impurities.
Green silicon carbide also helps enhance the mechanical performance of the ceramics. If you are involving the manufacture of precision silicon carbide components for aerospace, you may consider it. Moreover, green SiC can serve as a filler for coatings to improve wear resistance.
Besides the above applications, green silicon carbide is used in the semiconductor industry, photovoltaic silicon wafer processing, and the manufacture of highly stable semiconductor parts, meeting the requirements of high-end electronic devices.
Semiconductor Components Made by Green Silicon CarbideChoosing Black Silicon Carbide or Green Silicon Carbide?
The most suitable choice should align with your production requirements, processing materials, and budget. You may make a quick decision by the following 3 points.
Consider processing precision and material hardness
Black silicon carbide is not easily fractured and provides high processing efficiency. In coarse grinding or heavy-duty cutting, processed materials are relatively common with moderate precision requirements. You may consider black silicon carbide in this situation. Moreover, its cost is only 60% of the green one, effectively controlling your cost.
Green silicon carbide prevents impurities and surface scratches. For high-end precision grinding and polishing that need extremely high purity and surface precision, you should choose green silicon carbide. Note that green SiC is highly brittle. Sufficient care must be taken during the operation to prevent cracking.
Consider the applications
Black silicon carbide meets your needs for regular wear-resistant ceramics, honeycomb ceramics, and refractory materials. It can also be used as a raw material for general abrasives.
Green silicon carbide are used to manufacture precision ceramics and high-end abrasives. It is also used widely in high-tech fields, such as semiconductor manufacturing and photovoltaics.
Think about the cost
Black silicon carbide is the more suitable if you need high cost-effective one. At the same time, your production should not have special requirements for purity.
Green silicon carbide is preferred for industries that need extremely high purity and performance. If you have a sufficient budget, you can rely on the green one.
The table below provides references for you to make a choice. Get a quickly review.
| Item | Choose Black Silicon Carbide | Choose Green Silicon Carbide |
| Processing Precision | Coarse grinding Heavy-duty cutting Low precision requirements | Precision grinding Polishing High precision requirements |
| Processed Materials | Cast iron, common metals, stone, ordinary ceramic products | Cemented carbide, precision ceramics, semiconductor silicon wafers, optical glass |
| Applications | General wear-resistant ceramics, foam ceramics, refractories, ordinary abrasives, metallurgical deoxidation | Precision ceramics, high-end abrasives, semiconductor manufacturing, photovoltaics, high-end industrial coatings |
| Core Requirements | High efficiency, high toughness, low cost | High purity, high hardness, high precision |
Conclusion
Black silicon carbide brings excellent cost-effectiveness and efficiency. It is more suitable for general industrial environments. Green silicon carbide provides high purity and precision. It is employed in high-end industries that need fine processing. Clear your needs first to find the most suitable one for your industry, enhancing your production efficiency.
Finding silicon carbide tailored to your industry? Contact Newthink New Materials and tell us your needs. We will help you match the products best suited for your industry.
Thanks for your reading. Hope this article will be helpful.
FAQ
- Why does silicon carbide possess different colorslike black and green?
Different smelting temperatures and impurities result in different colors.
- What is the main difference between black silicon carbideand green silicon carbide?
Black silicon carbide is tougher and more cost-effective. Green silicon carbide has higher purity and hardness.
- What isthe definition ofgreen SiC?
Green silicon carbide is a high-purity ceramic material produced by quartz sand and petroleum coke at 2500℃.
- What is the applications of black SiC?
Black silicon carbide is mainly used for heavy-duty grinding, wear-resistant liners, metallurgy, and refractory manufacturing.
- What are the disadvantages of silicon carbide?
Silicon carbide is brittle and easily fractures under impact. As a result, it is expensive to produce and difficult to machine because of its hardness.
